This PDF file contains the front matter associated with SPIE Proceedings Volume 9230 including the Title Page, Copyright information, Table of Contents, Author Index, Introduction, and Conference Committee listing.

Based on a THz pipe-based near-field imaging system, we demonstrated the capability of THz imaging to diagnose human breast and liver cancers. Through THz near-field mapping of the absorption constants of cancer tissues, the acquired images can not only clearly distinguish cancer from normal tissues fast, automatically, and correctly without pathological H&E staining, but also identify the distribution region of cancer, which matches well with the identification with pathological examination. Due to its capability to perform quantitative analysis, our study indicates the potential of the THz pipe-based near-field imaging for future automation on human tumor pathological examinations and for quick definition of the tumor margins during the surgical procedure such as breast-conserving surgery. With the help of THz imaging, we can expect to economize the use of hospital and human resources.

Hepatocarcinoma, a malignant cancer, threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistance of the advanced hepatocarcinoma to chemotherapy. Berberine (Ber), an isoquinoline derivative alkaloid, has a wide range of pharmacological properties and is considered to have anti-hepatocarcinoma effects. However its low oral bioavailability restricts its wide application. In this report, Ber nanosuspension (Ber-NS) composed of Ber and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was prepared by high pressure homogenization technique. Both in vitro and in vivo anti-hepatocarcinoma effects of Ber-NS relative to effcacy of bulk Ber were evaluated. The particle size and zeta potential of Ber-NS were 73.1 ± 3.7 nm and 6.99 ± 0.17 mV, respectively. Ber-NS exhibited significant inhibitory effects against human HepG2 and Huh7 cells, and the corresponding IC₅₀ values were 8.1 and 4.7 μg/ml (18.3 and 6.5 μg/ml of Ber solution). In vivo studies also showed higher antitumor efficacy, and inhibition rates was 63.7% (41.4 % of Ber solution) at 100 mg/kg intragastric administration in the H22 solid tumor bearing mice. These results suggest that the delivery of Ber as a nanosuspension is a promising approach for treating hepatocarcinoma.

Noninvasive blood glucose level (BGL) monitoring has recently become a research hotspot in the world. Photoacoustic spectroscopy is a well-established, hybrid and promising noninvasive technique, which has already drawn many researchers’ attentions in recent years due to the advantage of overcoming the scattering light interference. As the preliminary exploration of photoacoustic BGL monitoring, a photoacoustic BGL monitoring set-up based on nanosecond pulsed laser with repetition rate of 20Hz and ultrasound transducer with central frequency of 9.55MHz was established in this paper. To explore the mechanism of the time resolved BGL photoacoustic signal, a series of in vitro experiments of glucose aqueous solutions were tested, the time resolved photoacoustic signals for different concentrations of glucose solutions under different output wavelengths were captured with the data average of 512 times. The peak-to-peak values of each solution were gotten at the wavelength interval of 10nm. Difference with the peak-to-peak value of pure water via subtractive spectroscopy, the characteristic wavelengths of glucose were gotten, and the optimum characteristic wavelengths were determined via data pre-processing and principle component analysis(PCA) algorithm, the calibration equation between concentration and the peak-to-peak value was gotten via multiple linear regression(MLR), and the calibration root mean square error(CRMSE) and the prediction root mean square error(PRMSE) of glucose level is all less than 10mg/dl under the correction equation.

The synchronous fluorescence (SF) technique can provide some useful information with the endogenous fluorophores in complex systems. The SF technique has been used in the characterization of the type I collagen in PBS solution (pH=7.4) and the photo-reaction of hypocrellin B (HB) with type I collagen in solution irradiation with the 475 nm light under saturated by oxygen, air and nitrogen respectively. The SF spectra show the peaks attribute to tyrosine residues (275 nm) and pyridinoline cross-link (325 nm) in collagen. The photo-induced reaction with HB causing the fluorescence quenching but no wavelength shift, this suggests the photo-reaction don’t changing the microenvironment of PYD cross-link. The fluorescence quenching rate is faster than others when the solution saturated by oxygen. The results imply that the photo-induced reaction is oxygen dependence.

In recent years, more and more Americans are diagnosed with prostate cancer, and the current detection methods still have some disadvantages. Photoacoustic imaging, as a new non-invasive imaging technique, has the capable of imaging complex tissue and owns the ability of early tumor imaging. And the photoacoustic signal of the tumor is bound up with its light energy distribution. In this paper, Monte Carlo method was used to simulate the light propagation in the prostate phantom. The pictures of light energy distribution by the irradiation of a pulsed laser were obtained. With the pulsed laser, according to the absorption coefficient of tumor, the local energy temporal changes in prostate can be illustrated. As we known, the local photoacoustic signal has a relationship with the change of light energy. Then we can see the influence of photoacoustic signal under the changes of the absorption coefficient of tumor.

Food-borne pathogens such as Listeria monocytogenes have been recognized as a major cause of human infections worldwide, leading to substantial health problems. Food-borne pathogen identification needs to be simpler, cheaper and more reliable than the current traditional methods. Here, we have constructed a low-cost paper biosensor for the detection of viable pathogenic bacteria with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes. The amplification products were applied to the paper biosensor to perform a visual test, in which endpoint detection was performed using sandwich hybridization assays. When the RNA products migrated along the paper biosensor by capillary action, the gold nanoparticles accumulated at the designated Test line and Control line. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from Listeria monocytogenes could be detected. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. The developed method is suitable for point-of-care applications to detect food-borne pathogens, as it can effectively overcome the false-positive results caused by amplifying nonviable Listeria monocytogenes.

When measuring the Mueller matrix images of a sample with a GRIN lens, many Mueller matrix elements will be seriously distorted by the intrinsic birefringence of the GRIN lens. Imaging polarimeter measurements of GRIN lenses showed radially symmetric phase retardance polarization. We simulated the Mueller matrices of the GRIN lens with light of different incident angles, removed the polarization artifacts with the simulated results and recovered the polarization features of the sample. The results demonstrate the possibility of performing Mueller matrix measurements using endoscopes or other optical instruments with strong birefringence.

PI3K-Akt signaling pathway plays the key role in cell apoptosis and survival, and the components of PI3K /Akt signaling pathway are often abnormally expressed in human tumors. Therefore, determination of the Akt (protein kinase B, PKB) messenger ribonucleic acid (mRNA) expression is significantly important in understanding the mechanism of tumor progression. In this study, we designed a special hairpin deoxyribonucleic acid (DNA) functionalized with gold nanoparticles and fluorescein isothiocyanate(FITC) as a beacon for detecting human Akt mRNA. Spectrofluorometer was used to detect the fluorescence quenching and recovery of the beacons, and laser confocal scanning microscopy was adopted to image Akt mRNA in cells. The results showed that this beacon could sensitively and quantitatively measure the Akt mRNA in living cells . This strategy is potentially useful for the cellular imaging of RNA or protein expression in living cells.

Exploiting the bright and colorful photophysical properties of semiconductor quantum dots (QDs) is an onward trend in biotechnology and QDs have been widely used as fluorescent probes in cell-targeted imaging. However, nonspecific binding to cellular membranes has been a major challenge. In this study, high quality cadmium telluride (CdTe) quantum dots with different particle sizes were prepared via hydrothermal method. The surface of the QDs was modified with the chemically reduced bovine serum albumin (BSA) for effective reduction of nonspecific binding in cell targeting. Here,the as–prepared QDs exhibits tunable photoluminescence (PL) emission between 525nm and 620 nm.BSA-coated QDs which also provide reaction sites for conjugation of targeting ligands is mainly achieved by multiple mercapto groups in BSA macromolecules as multidentate ligands and partially by ligand exchange interaction between BSA and QDs. The BSA-coated QDs, with an overwhelming majority of hydrodynamic diameter size of 15nm ,are found to exhibit strong fluorescent intensities. The cellular uptake and localization of QDs was studied using laser confocal scanning microscopy. The results indicated that the nonspecific cellular binding is effectively reduced by BSA-coated QDs, compared with the N-acetyl-L-cysteine (NAC) -coated CdTe QDs.

Quantum dots (QDs) is a promising candidate for biomedical imaging. However, the bio-toxicity of traditional quantum dots obstructed their further application seriously. In this work, a simple solution growth method was utilized to synthesize ZnO QDs. However, their self-assemble feature makes them unstable in aqueous solution. Furthermore, (3-Aminopropyl) triethoxysilane was selected as a capping agent to stabilize ZnO QDs and then ZnO@SiO₂ nanoparticles were obtained. They dispersed excellently in water and exhibited favorable fluorescence properties owing to the protection of silane. The biocompatability of ZnO@SiO₂ nanoparticles was verified by MTT assy. The cell affinity studies demonstrated that ZnO@SiO₂ nanoparticles could be uptaken by cells efficiently. Therefore, the as-prepared ZnO@SiO₂ nanoparticles is a promising candidate for applications in cell imaging.

With the copolymer micelles being widely used in the field of tumor therapy, environmental responding copolymers had gained large interest. In our previous work, we synthesized the nanovehicle N-succinyl-N’-4-(2-nitrobenzyloxy)-succinyl-chitosan micelles (SNSC) that were composed of a light-sensitive triggering group 2-nitrobenzyl alcohol on the hydrophobic block and succinyl group modified chitosan. We have demonstrated that the use of a continuous-wave diode near-infrared (NIR) laser could cleave the amphiphilic block copolymer micelles and trigger the release of their “payloads”. In the present study, SNSC were further optimized and characterized by UV-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy (TEM) that was used to display the two-photon photolysis of SNSC micelles under the NIR irradiation (765nm) . Later on, laser confocal fluorescence microscopy was used to investigate the fluorescein (Ex/Em: 490/520 nm)-loaded SNSC imaging ability. As a result, the optimized SNSCs exhibited higher loading efficiency and smaller size which contributed to an improved stability, drug delivery and cell imaging abilities.

Mammalian target of rapamycin (mTOR) as a key protein in PI3K-AKT-mTOR signaling pathway ,plays an important role in the tumor growth. The small interfering RNA (siRNA) of mTOR would decrease the expression of mTOR protein. In this study, we screened the mTOR siRNA sequence using MATLAB software and ascertained it based on BLAST. Then we imported it with the aid of Lipofectamine2000 into MCF-7 cancer cells where mTOR is over expression .And then we used a special hairpin deoxyribonucleic acid (DNA) for combining with the human mTOR mRNA to functionalize gold nanoparticles, which served as a molecule beacon for detecting human mTOR mRNA transcription. Laser scanning confocal microscope and Flow Cytometry data showed that the quenching efficiency was up to 90%,which are consistent with the RT-PCR measurement and Western. Compared to the previous approaches, this beacon has advantages of higher target to background ratio of detection. The strategy reported in this study is a promising approach for the intracellular measurement of the result of siRNA or protein expression in living cells, and has great potential in the study of drug screening and discovery.

MicroRNAs (miRNAs) participate in the significant processes of life course, can be used as quantificational biomarkers for cellular level researches and related diseases. Conventional methods of miRNAs’ quantitative detection are obsessed with low sensitivity, time and labour consuming. Otherwise, the emerging miRNAs detection approaches are mostly exposed to the expensive equipment demands and the professional operation, remains at the stage of laboratory and concept demonstration phase. Herein, we designed a novel miRNAs detection platform that based on enzyme-free DNA circuits and electrochemical luminescence (ECL). MicroRNA21 was chosen as the ideal analyte of this platform. The whole process consists of enzyme-free DNA circuits and ECL signal giving-out steps, achieves advantages of operating in constant temperature condition, without the participation of the enzyme, preferable sensitivity and specificity. Through this approach, the sensitivity achieved at 10pM. It is indicated that this miRNAs detection platform possesses potentials to be an innovation of miRNA detection technologies in routine tests. Benefits of the high penetration of ECL in well-equipped medical establishment, this approach could greatly lessen the obstacles in process of popularization and possess excellent prospects of practical application.

Fluorescence molecular tomography (FMT) is an important molecular imaging modality developed to reveal the three-dimensional distribution of fluorescent targets using fluorescent measurements and appropriate image reconstruction methods. During the past years, many efforts have been devoted to the development of efficient inverse reconstruction methods for FMT. In this study, a projected restarted framework is proposed, using an inner–outer iteration scheme to compute the nonnegative solutions of the ill-posed non-square linear systems in FMT. In the inner iteration, conventional inverse reconstruction methods are employed to obtain a solution for the residual equation of the original linear system. In the outer iteration, the solution of the original linear system is updated using the results obtained in the inner iteration. Two kinds of projected restarted methods are obtained based on Tikhonov regularization (TR) and Generalized Minimal RESidual (GMRES). Both simulation and phantom studies are carried out to evaluate the performance of the proposed methods in the situation of limited projections, which is very helpful for reducing the acquisition time of fluorescent measurements and suitable for resolving fast biological processes in vivo. Compared with the conventional TR and GMRES needing 36 or even more projections, the projected restarted methods can maintain the image quality when limited projections (n≥4) are employed in the reconstruction. In addition, satisfactory reconstruction results based on the projected restarted methods can be obtained even when high noise level (SNR=20 dB) or closely adjacent targets (edge-to-edge distance between two targets is 0.4 cm) are encountered.

The adrenergic system plays an important role in regulation of central and peripheral circulation in normal state and during hemorrhage. Because the impaired gastric mucosal blood flow (GMBF) is the major cause of gastroduodenal lesions, including ulcer bleeding (UB), we studied the adrenergic mechanism responsible for regulation of GMBF in rats with a model of stress-induced UB (SUB) using the laser Doppler flowmetry (LDF). First, we examined the effect of adrenaline on GMBF in rats under normal state and during UB. In all healthy animals the submucosal adrenaline injection caused a decrease in local GMBF. During UB the submucosal injection of adrenaline was accompanied by less pronounced GMBF suppression in 30,3% rats with SUB vs. healthy ones. In 69,7% rats with SUB we observed the increase in local GMBF after submucosal injection of adrenaline. Second, we studied the sensitivity of gastric β2-adrenoreceptors and the activity of two factors which are involved in β2-adrenomediated vasorelaxation-K_ATP -channels and NO. The effects of submucosal injection of isoproterenol, ICI118551 and glybenclamide on GMBF as well as NO levels in gastric tissue were significantly elevated in rats with SUB vs. healthy rats. Thus, our results indicate that high activation of gastric β2-adrenoreceptors associated with the increased vascular K_ATP -channels activity and elevated NO production is the important adrenergic mechanism implicated in the pathogenesis of UB.

Bioluminescence tomography (BLT) is an important optical molecular imaging modality aimed at visualizing physiological and pathological processes at cellular and molecular levels. While the forward process of light propagation is described by the diffusion approximation to radiative transfer equation, BLT is the inverse problem to reconstruct the 3D localization and quantification of internal bioluminescent sources distribution. Due to the inherent ill-posedness of the BLT problem, regularization is generally indispensable to obtain more favorable reconstruction. In particular, total variation (TV) regularization is known to be effective for piecewise-constant source distribution which can permit sharp discontinuities and preserve edges. However, total variation regularization generally suffers from the unsatisfactory staircasing effect. In this work, we introduce the Bregman iterative regularization to alleviate this degeneration and enhance the numerical reconstruction of BLT. Based on the existing Landweber method (LM), we put forward the Bregman-LM-TV algorithm for BLT. Numerical experiments are carried out and preliminary simulation results are reported to evaluate the proposed algorithms. It is found that Bregman-LM-TV can significantly outperform the individual Landweber method for BLT when the source distribution is piecewise-constant.

Raman spectroscopy is a rapidly non-invasive technique with great potential for biomedical research. The aim of this study was to evaluate the feasibility of using Raman spectroscopy of human saliva for acute myocardial infarction (AMI) detection. Raman spectroscopy measurements were performed on two groups of saliva samples: one group from patients (n=30) with confirmed AMI and the other group from healthy controls (n=31). The diagnostic performance for differentiating AMI saliva from normal saliva was evaluated by multivariate statistical analysis. The combination of principal component analysis (PCA) and linear discriminate analysis (LDA) of the measured Raman spectra separated the spectral features of the two groups into two distinct clusters with little overlaps, rendering the sensitivity of 80.0% and specificity of 80.6%. The results from this exploratory study demonstrated that Raman spectroscopy of human saliva can serve as a potentially clinical tool for rapid AMI detection and screening.

Fibroadenoma (FA), typically composed of stroma and epithelial cells, is a very common benign breast disease. Women with FA are associated with an increased risk of future breast cancer. The objective of this study was to demonstrate the potential of multiphoton laser scanning microscopy (MPLSM) for characterizing the morphology of collagen in the human breast fibroadenomas. In the study, high-contrast SHG images of human normal breast tissues and fibroadenoma tissues were obtained for comparison. The morphology of collagen was different between normal breast tissue and fibroadenoma. This study shows that MPLSM has the ability to distinguish fibroadenoma tissues from the normal breast tissues based on the noninvasive SHG imaging. With the advent of the clinical portability of miniature MPLSM, we believe that the technique has great potential to be used in vivo studies and for monitoring the treatment responses of fibroadenomas in clinical.

We report here our study on ultrafast spectral dynamics in the interior of SNase using picosecond-resolved emission spectra of tryptophan through site-directed mutagenesis. By probing the solvation dynamics in the nucleotide binding pocket and the Ca²⁺ binding pocket as well as in the interior of hydrophobic core, two robust relaxation time scales on a few picoseconds and on tens of picoseconds have been observed. Both two time scales are strongly correlated with local structural and chemical properties of protein. These distinct differences in solvation dynamics reflect the intimate relationship between the dynamic structures and the functions of enzyme.

Recently, three-dimensional (3D) super resolution imaging of cellular structures in thick samples has been enabled with the wide-field super-resolution fluorescence microscopy based on double helix point spread function (DH-PSF). However, when the sample is Epi-illuminated, much background fluorescence from those excited molecules out-of-focus will reduce the signal-to-noise ratio (SNR) of the image in-focus. In this paper, we resort to a selective-plane illumination strategy, which has been used for tissue-level imaging and single molecule tracking, to eliminate out-of-focus background and to improve SNR and the localization accuracy of the standard DH-PSF super-resolution imaging in thick samples. We present a novel super-resolution microscopy that combine selective-plane illumination and DH-PSF. The setup utilizes a well-defined laser light sheet which theoretical thickness is 1.7μm (FWHM) at 640nm excitation wavelength. The image SNR of DH-PSF microscopy between selective-plane illumination and Epi-illumination are compared. As we expect, the SNR of the DH-PSF microscopy based selective-plane illumination is increased remarkably. So, 3D localization precision of DH-PSF would be improved significantly. We demonstrate its capabilities by studying 3D localizing of single fluorescent particles. These features will provide high thick samples compatibility for future biomedical applications.

Mueller matrix polarimetry techniques contain rich micro-structural information of samples, such as the sizes and refractive indices of scatterers. Recently, Mueller matrix imaging methods have shown great potentials as powerful tools for biomedical diagnosis. However, the orientations of anisotropic fibrous structures in tissues have prominent influence on Mueller matrix measurements, resulting in difficulties for extracting micro-structural information effectively. In this paper, we apply the backscattering Mueller matrix imaging technique to biological samples with different microstructures, such as chicken heart muscle, bovine skeletal muscle, porcine liver and fat tissues. Experimental results show that the directions of the muscle fibers have prominent influence on the Mueller matrix elements. In order to reduce the orientation influence, we adopt the rotation-independent MMT and RLPI parameters, which were proposed in our previous studies, to the tissue samples. Preliminary results in this paper show that the orientation-independent parameters and their statistic features are helpful for analyzing the tissues to obtain their micro-structural properties. Since the micro-structure variations are often related to the pathological changes, the method can be applied to microscope imaging techniques and used to detect abnormal tissues such as cancer and other lesions for diagnosis purposes.

Objective: Nowadays, the nanomaterials have been applied in every aspects of our life, including cosmetics, fresh-keeping, antisepsis and medicines. However, we know little about the toxic effects of nanoparticles towards plants. In this thesis, we synthesized quantum dots (QDs), and then toxicity and invasive effects of QDs for mung beans were investigated. Methods: We synthesised red CdTe QDs in water sphase with L-Cystein stabilizers, then prepared different concentration of QDs solution to cultivate mung bean plant, the radical length of mung beans was measured after four days every day, after 7 days, the distribution of QDs in mung bean plant was recorded under the microscopic. Results: The result showed the QDs inhibited the growth of mung beans, the higher the concentration of QDs was, the greater the inhibition effect was. After 7 days, the radicle average lengths of mung beans in different concentrations of QDs solution（blank 0.1μmol/L 0.2μmol/L 0.5 μmol/L 1 μmol/L）were 19.350± 0.427, 14.050± 0.879, 10.525± 0.554, 7.250± 0.522, 7.650± 0.229. The QDs mostly adhered onto the root surface and hairs. Conclusion: In conclusion, the QDs synthesized with L-cystein have effects on the growth of mung beans. However, it is necessary to do more experiments to confirm the mechanism of the toxicity effect of QDs on plants.

Fluorescence molecular tomography (FMT) can quantify fluorophore concentration based on the static assumption that the fluorophore concentration is time invariant during the multi-projection acquisition process. However, when investigating the kinetic behaviors of fluorophores, especially when the change of fluorophore concentration is fast, the static assumption would provide inadequate temporal information and bring noise in the reconstruction results. In this study, we propose a dual-excitation approach for dynamic FMT to effectively image the time-varying fluorophores. Dual-excitation with the same source-detector pair is employed to collect two fluorescence measurements with a fixed time interval. Then, linear extrapolation is applied to the two measurements to compensate the measurement data from the adjacent source-detector pair. With the compensated measurement data over 360° projections, a sequence of fluorophore concentration images can be reconstructed with Tikhonov regularization. Numerical simulation results demonstrate the feasibility of the proposed approach in improving the temporal resolution and reducing the noise in dynamic FMT.

The patient specific geometry of the heart is of interest for a number of diagnostic methods, e.g., when modeling the inverse electrocardiography (ECG) problem. One approach to get images of the heart is three-dimensional ultrasound. However, segmentation of the surface is complicated and segmentation methods are typically validated against manually drawn contours. This requires considerable expert knowledge. Hence, we have developed a setup that allows studying the accuracy of image segmentation from cardiac ultrasound. Using an optical tracking system, we have measured the three-dimensional surface of an isolated porcine heart. We studied whether the actual geometry can be reconstructed from both optical and ultrasound images. We illustrate the use of our approach in quantifying the segmentation result for a three-dimensional region-based active contour algorithm.

Objective: In recent years, semiconducting polymer dots (Pdots)have caught considerable attention for their outstanding optical characteristics in biomedical imaging applications. Not as semiconductor quantum dots, Pdots are composed of nonmetallic material and their biological effects remain unclear. In this work, we investigated the effects of a band new polymer dots on bioactivity of mouse sperm using a computer-aided sperm analysis system(CASA) and an in vitro fertilization (IVF) model. Methods: The semiconducting polymer dots used in this study is CN-PPV Pdots, which emits in the orange wavelength range with high brightness. Epididymal mouse sperm were collected from 7-8weeks old Balb/c mouse. Firstly, CN-PPV Pdots was added into the Human Tubal Fluid (HTF) media at various concentrations (0, 1, 10, 100 nmol/L respectively ), then sperm bioactivity and vitality were evaluated every 10 minutes. Secondly, the treated sperm were co-cultured with matured oocytes in HTF media, fertilization rate and oocytes development were recorded after 24 hours co-incubation. Results: Sperm viability in the control group (0 nmol/L) and experimental group (1, 10,100 nmol/L) were 57.20±4.51%, 58.17±4.81%, 55.50±4.52%, 46.26%±3.83%, respectively. Fertilization rate in different groups showed no obvious differences, control group (0 nmol/L) and experimental group (1, 10, 100 nmol/L) were 38.75±1.71%, 37.01±4.69%, 32.75±1.71%, 35.24±2.37%, respectively. Conclusion: Our data indicated that the CN-PPV Pdots had a very high biocompatibility on sperm in both the activation and the IVF process, even in extreme high Pdots concentration,the sperm bioactivity only got slight restrained. The effect of CN-PPV Pdots seems has no or little toxicity,and the long-term embryonic development has yet to be verified.

Because of their excellent near-infrared (NIR) optical properties, phthalocyanines (Pcs) have been regarded as promising therapy agents for fluorescence image-guided drug delivery and noninvasive treatment of tumors by photodynamic therapy (PDT). Nevertheless, phthalocyanines are substantially limited in clinical applications owing to their poor solubility, aggregation and insufficient selectivity for cancer cells. To address these issues, we have developed a novel dendrimer-based theranostic nanoparticle for tumor-targeted delivery of phthalocyanine. The preparation procedure involved the modification of the silicon (IV) phthalocyanine molecule with a dendritic axially substitution, which significantly enhances their photophysical property. In order to improve biocompatibility and tumor-targeted delivery, the hydrophobic dendritic phthalocyanine was encapsulated by diblock amphiphilic copolymer poly (ethylene glycol)-poly (Epsilon-caprolactone) (MPEG-PCL) to form a polymeric nanoparticle. The polymeric nanoparticle is spherical with a diameter at about 90 nm. The photophysical property of the polymeric nanoparticle was studied by UV/Vis and fluorescence spectroscopic methods. Compared with the free dendritic phthalocyanine, the Q band of the polymeric nanoparticle was red-shifted, and the fluorescence intensity decreased. Furthermore, the polymeric nanoparticle has a relatively high loading amount and encapsulation rate. Therefore, the polymeric nanoparticle would be a promising third-generation photosensitizer (PS) for PDT.

Molecular dynamics (MD) simulation provides a quantitative method for screening efficient optical clearing agents. Some excellent optical clearing agents were obtained through the MD simulation of alcohols with hydroxyl groups. Among of the agents, fructose, one of polyols has the better efficacy which is one of monoaccharides. In comparison, disaccharides received little attention. In this study, sucrose and maltose were screened from common disaccharides for comparing with fructose. Actually, each agent has different saturation concentration. Here, the combination of molecular dynamic simulation and in vitro experiment was employed in this study. Firstly, the hydrogen bonds were used to predict the optical clearing potential of sucrose, maltose and fructose by using molecular dynamic simulation, respectively. The simulated results indicated that the optical clearing potential in a descending order as: sucrose, maltose and fructose. The reduced scattering coefficient of in vitro rat skin samples was used to evaluate the skin optical clearing potential based on measurements of reflectance and transmittance using a commercial spectrophotometer with an integrating sphere. Both the experimental and simulated results show that for the same concentration, disaccharides have better optical clearing potential than fructose. However, maltose has too low saturation concentration to produce similar optical clearing efficacy as the other two. By contrast, sucrose is the best one even though it has lower saturation concentrations than fructose.

Lipid rafts are cholesterol- and glycosphingolipids- enriched microdomains on plasma membrane surface of mammal cells, involved in a variety of cellular processes. Depleting cholesterol from the plasma membrane by drugs influences the trafficking of lipid raft markers. Optical imaging techniques are powerful tools to study lipid rafts in live cells due to its noninvasive feature. In this study, breast cancer cells MCF-7 were treated with different concentrations of MβCD to deplete cholesterol and an environmentally sensitive fluorescence probe, Laurdan was loaded to image lipid order by two-photon microscopy. The generalized polarization (GP) values were calculated to distinguish the lipid order and disorder phase. GP images and GP distributions of native and cholesterol-depleted MCF-7 cells were obtained. Our results suggest that even at low concentration (0.5 mM) of MβCD, the morphology of the MCF-7 cells changes. Small high GP areas (lipid order phase) decrease more rapidly than low GP areas (lipid disorder phase), indicating that lipid raft structure was altered more severely than nonraft domains. The data demonstrates that cholesterol dramatically affect raft coverage and plasma membrane fluidity in living cells.

A label-free high resolution photoacoustic microscopy (PAM) system for imaging cellular malformation is presented. The carbon fibers were used to testify the lateral resolution of the PAM. Currently, the lateral resolution is better than 2.7 μm. The human normal red blood cells (RBCs) were used to prove the imaging capability of the system, and a single red blood cell was mapped with high contrast. Moreover, the iron deficiency anemia RBCs were clearly distinguished from the cell morphology by using the PAM. The experimental results demonstrate that the photoacoustic microscopy system can accomplish label-free photoacoustic imaging and that it has clinical potential for use in the detection of erythrocytes and blood vessels malformation.

Mechanical properties of living cells play an important role in understanding various cells’ function and state. Therefore cell biomechanics is expected to become a useful tool for cancer diagnosis. In this study, atomic force microscopy (AFM) using a square pyramid probe was performed to investigate cancerous (MCF-7) and benign (MCF-10A) human breast epithelial cells. The new QI^TM mode was used to acquire high-resolution topographic images and elasticity of living cells. Furthermore, individual force curves were recorded at maximum loads of 0.2, 0.5 and 1 nN, and the dependence of cell’s elasticity with loading force was discussed. It was showed that the cancerous cells exhibited smaller elasticity modulus in comparison to non-cancerous counterparts. The elasticity modulus increased as the loading force increased from 0.2 nN to 1 nN. This observation indicates that loading force affects the cell’s apparent elasticity and it is important to choose the appropriate force applied to cells in order to distinguish normal and cancer cells. The results reveal that the mechanical properties of living cells measured by atomic force microscopy may be a useful indicator of cell type and disease.

Ultrasound modulated fluorescence tomography (USMFT) has the potential to be a useful technique to obtain fluorescence images with optical contrast and ultrasound (US) resolution in deep tissue. However, due to the intrinsic incoherent properties of fluorescence and the low modulation depth, the signal-to-noise ratio (SNR) and image contrast are poor. In this paper, the feasibility of using pyrene-labelled nanosize liposomes as contrast agents to improve the modulation depth in USMFT is investigated by using a light-scattering technique. Compared with microbubbles (MBs), which have been applied to USMFT to improve the modulation depth, liposomes are more stable and they can be manufactured with good repeatability. Also liposomes have a lower US scattering coefficient due to their liquid core as compared to the gas core of MBs, which can be advantageous when switching on fluorescence in a region of interest is required. Pyrene can form excimer fluorescence when in close proximity to other pyrene molecules. The exposure of these liposomes to US can change the collision rate of the pyrene molecules and hence modulate the optical emission. In the current work, 100 nm sized liposomes composed of varying concentrations of pyrene-labelled phospholipids were investigated to identify a suitable liposome-based US contrast agent candidate. The fluorescence emission of the pyrene-labelled liposomes insonified by continuous US were studied. It has been observed that the excimer emission from 0.5 mol% pyrene-labelled liposome is US sensitive at pressures between 1.4 MPa and 2.7 MPa. Possible fluorescence modulation mechanisms and application of pyrene-labelled liposomes for high-resolution, high-contrast fluorescence imaging are also discussed.

Despite the introduction of high-technology methods of detection and diagnosis, screening of primary liver cancer (PLC) remains imperfect. To diagnosis PLC earlier, Surface-enhanced Raman spectroscopy (SERS) coupled with cellulose-acetate membrane electrophoresis were introduced to separate human serum albumin and SERS spectra. Three groups (15 normal persons’ samples, 17 hepatitis/cirrhosis samples, 15 cases of PLC) of serum albumin were tested. Silver colloid was used to obtain SERS spectra of human serum albumin. Principal component analysis (PCA) and linear discriminant analysis (LDA) were also employed for statistical analysis. The mean Raman spectra of three groups and the difference spectra of any two suggested that the albumin has changed in liver patients. Compared to normal groups, some Raman peaks have shifted or even disappeared in hepatitis/cirrhosis and PLCs groups. The sensitivity and specificity between PLCs and normal groups is 80% and 93.3%. Among hepatitis/cirrhosis and normal groups, the sensitivity is 88.2% and specificity is also 93.3%. Besides, the sensitivity and specificity between PLCs and hepatitis/cirrhosis groups is 86.7% and 76.5%. All the above data and results indicated that early screening of PLC is potential by SERS in different stages of liver disease before cancer occurs.

This paper focuses on the absorption effect due to pathological changes. Using Monte Carlo simulation on our previously proposed sphere-cylinder-birefringence model (SCBM), and forward scattering experiments on phantoms containing polystyrene microspheres, well-aligned glass fibers and ink solution, we investigate how depolarization, retardance and diattenuation change with tissue absorption by decomposing the Mueller matrix using Mueller matrix polar decomposition method. According to the simulation and experimental results, this paper presents the influence of absorption on polarization scattering process from three aspects: firstly, the absorption depresses the depolarization contributed by the spherical and cylindrical scatterers; secondly, it decreases the retardance due to the anisotropic cylinder; thirdly, the increasing absorption enhances the diattenuation from cylindrical scatterers.

With the widespread use of high-power laser systems operating within the wavelength region of approximately 1.3 to 1.4 μm, it becomes very necessary to refine the laser safety guidelines setting the exposure limits for the eye and skin. In this paper, an optical-thermal-damage model was developed to simulate laser propagation, energy deposition, heat transfer and thermal damage in the skin for 1.319 μm laser irradiation. Meanwhile, an experiment was also conducted in vitro to measure the tempreture history of a porcine skin specimen irradiated by a 1.319 μm laser. Predictions from the model included light distribution in the skin, temperature response and thermal damge level of the tissue. It was shown that the light distribution region was much larger than that of the incident laser at the wavelength of 1.319 μm, and the maximum value of the fluence rate located on the interior region of the skin, not on the surface. By comparing the calculated temperature curve with the experimentally recorded temperautre data, good agreement was shown betweeen them, which validated the numerical model. The model also indicated that the damage integral changed little when the temperature of skin tissue was lower than about 55 °C, after that, the integral increased rapidly and denatunation of the tissue would occur. Based on this model, we can further explore the damage mechanisms and trends for the skin and eye within the wavelength region of 1.3 μm to 1.4 μm, incorporating with in vivo experimental investigations.

Human hair is a keratinous tissue composed mostly of flexible keratin, which can form a complex architecture consisting of distinct compartments or units (e.g. hair bulb, inner root sheath, shaft). Variations in hair shaft morphology can reflect ethnical diversity, but may also indicate internal diseases, nutritional deficiency, or hair and scalp disorders. Hair shaft abnormalities in cross section and diameter, as well as ultramorphological characterization and follicle shapes, might be visualized non-invasively by high-speed 2D and 3D optical coherence tomography (OCT). In this study, swept source OCT (ThorLabs) was used to examine human hair. Preliminary results showed that the high-speed OCT was a suitable and promising tool for non-invasive analysis of hair conditions.

In order to measure the axial flowing velocity of a suspension carbon particles of tens of micometer-scale, the photoacoustic doppler frequency shift was calculated from a series of individual A scans using a autocorrelation method. A 532nm pulsed laser with the repetition rate of 20Hz was used as a pumping source to generate photoacoustic signal. The photoacoustic signals were detected using a focused PZT ultrasound transducer with central frequency of 5MHz. The suspension of carbon particles was driven by a syringe pump. Firstly, the complex photoacoustic signal was calculated by the Hilbert transformation from time-domain photoacoustic signal. The complex photoacoustic signal was then autocorrelated to calculate doppler frequency shift. The flow velocity was calculated by averaging the autocorrelation results of individual A scans. In comparison , the previously reported data processing methods using cross-correlation method in time domain or frequency domain require high sequential scanning rate or high laser repetition rate up to several kHz to avoid aliasing or uncorrelation between sequential waveform pairs. But it is difficult to get several kHz repetition rate for a single pulsed laser and the correlation between waveform pairs of sequential A scans were also limited by the laser repetition rate. To solve the problem, we used the autocorrelation method of individual A scans to calculated Doppler frequency shift. The time delay can be user defined to avoid aliasing. The feasibility of the proposed autocorrelation method was preliminarily demonstrated by quantifying the motion of a carbon particles suspension flow from 5 to 60 mm/s. The experimental results showed that the autocorrelation result approximately agreed with the setting velocity linearly.

Fourier transform infrared imaging (FTIRI) combined with chemometrics can be used to detect the structure of bio-macromolecule, measure the concentrations of some components, and so on. In this study, FTIRI with Partial Least-Squares (PLS) regression was applied to study the concentration of two main components in bovine nasal cartilage (BNC), collagen and proteoglycan. An infrared spectrum library was built by mixing the collagen and chondroitin 6-sulfate (main of proteoglycan) at different ratios. Some pretreatments are needed for building PLS model. FTIR images were collected from BNC sections at 6.25μm and 25μm pixel size. The spectra extracted from BNC-FTIR images were imported into the PLS regression program to predict the concentrations of collagen and proteoglycan. These PLS-determined concentrations are agreed with the result in our previous work and biochemical analytical results. The prediction shows that the concentrations of collagen and proteoglycan in BNC are comparative on the whole. However, the concentration of proteoglycan is a litter higher than that of collagen, to some extent.

Laminar optical tomography (LOT) is a new mesoscopic functional optical imaging technique. Currently, the forward problem of LOT image reconstruction is generally solved on the basis of Monte-Carlo (MC) methods. However, considering the nonlinear nature of the image reconstruction in LOT, with the increasing number of source positions, methods based on MC takes too much computation time. Based on the scheme of trajectory translation and target voxel regression (TT&TVR) proposed by our group, this paper develops a fast 3D image reconstruction algorithm. The algorithm is applied to the absorption reconstruction of the layered inhomogeneous media. Results demonstrate that the reconstructing time is less than 15min with the X-Y-Z section of the sample subdivided into 50 × 50 × 10 voxels, and the target size and quantitativeness ratio can be obtained in a satisfying accuracy.

Folliculitis, furunculosis and acne vulgaris are very common skin disorders of the hair follicles and are associated with large grease-producing (sebaceous) glands. Although the detailed mechanisms involved these skin disorders are not fully understood, it is believed that the bacteria Propionibacterium acnes and Staphylococcus aureus are the key pathogenic factors involved. Conventional treatments targeting the pathogenic factors include a variety of topical and oral medications such as antibiotics. The wide use of antibiotics leads to bacterial resistance, and hence there is a need for new alternatives in above bacterial skin treatment. Photodynamic antimicrobial chemotherapy (PACT) is based on an initial photosensitization of the infected area, followed by irradiation with visible light, producing singlet oxygen which is cytotoxic to bacteria. Herein we reported a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-(Lys)₅) and its PACT effect for the bacteria involved in these skin infections. Our results demonstrated strong bactericidal effects of this photosensitizer on both strains of the bacteria, suggesting ZnPc-(Lys)₅ as a promising antimicrobial photosensitizer for the treatment of infectious diseases caused by these bacteria.

Upconversion nanoparticles (UCNPs) have attracted much attention as novel contrast agents for low-background biomedical imaging and potential photosensitizer carriers for photodynamic therapy (PDT) in deep tissues. In this work, firstly we synthesized NaYF₄:Yb³⁺,Tm³⁺@NaYF₄:Yb³⁺,Er³⁺ core-shell structured UCNPs with multiple emission peaks (e.g. 480, 539, 654 and 800 nm) by a seeded growth approach. By coating folate-modified amphiphilic chitosan (FASOC) on UCNPs, the as-prepared UCNPs were favorably endowed with good water solubility and the enhanced tumor-selectivity to cancer cells that overexpressed folate receptor. Then, water-insoluble photosensitizer zinc(II) phthalocyanine (ZnPc) was loaded into the FASOC-UCNPs via hydrophobic interactions for potential near-infrared light induced photodynamic therapy (PDT). Our results indicate that the multifunctional FASOC-UCNP-ZnPc nanoconstruct has efficient NIR-to-NIR upconversion luminescence and PDT abilities, which could be potentially employed as a theranostic platform for cancer treatment.

In order to improve Doxorubicin (Dox) targeting in vivo and reduce toxicity, use the targeting ligand 2-deoxy-aminoglucose (2DG) to modify Doxorubicin to form a new anti-tumor drug. The products was charactered by ¹H-NMR, MS, and the targeting research by near-infrared imaging. Compared with Dox , the product treating MCF-7 and U87MG cells shows higher antitumor activity in vitro by MTT assay. In conclusion, the modified product effectively enhance the targeting and pharmacodynamics in contrast with Dox, and it would be a potential therapeutic drug for cancer.

Recently, three-dimensional GO-based hydrogels have attracted great attention due to the unique advantages. It is generally know that bacteria are everywhere and many of them could cause the diseases and threaten human health. However, developing new antibacterial materials with high-efficiency, low cost, broad-spectrum, and easy recycling is still a great challenge. Herein, inspired by mussel, we synthesized benzalkonium bromide/polydopamine/reduced graphene oxide hydrogel (BKB/PDA/rGOG). The as-prepared three-dimensional hydrogels were characterized by scanning eletron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The resultant hydrogels exhibited strong antibacterial effects to both Gram-negative and Gram-positive bacteria due to the synergistic effect of graphene oxide and benzalkonium bromide. In addition, the resultant hydrogels could be removed easily from the resolution, which was undoubtedly good news for industry application.

Objective: Over the past decade, fluorescent semiconductor nanocrystals, also known as quantum dots (QDs), have been applied in biomedical imaging in vitro and in vivo because of their fascinating optical properties. In this work, we investigated the application of CdTe QDs for tumor fluorescence in vivo imaging. Methods: The transparent dorsal skin fold window chamber (DSFC) was constructed on the 4~6 week-old BALB/c mice. The melanoma cells stably expressing green fluorescent protein ---ZsGreen were transplanted into the chamber and the melanoma DSFC model was established successfully. The water soluble CdTe QDs were synthesized and then administrated in the model through the tail intravenous injection. The fluorescent expression of B16 cells were assayed by fluorescent microscopy, the tumor growth, the blood capillaries distributions and its dynamic changes were observed by stereomicroscopy and laser scanning confocal microscopy. Results: The results demonstrated that the expression efficiency of ZsGreen was 41%, which met the experimental requirement. The tumors was visible inside the chamber after implantation of melanoma cells for 5~6 days, while no obvious changes in mice behaviors were found. After injection of the QDs, CdTe QDs accumulated at the invading edge of a range of solid tumor. We could also observe the tumor cells growth near the blood vessels, the angiogenesis occurred inside the tumor and the local blood capillaries increased. Conclusions: This work provided a new strategy for the tumor in vivo imaging and the development of targeted antineoplastic drugs.

Our previous studies have demonstrated that as a mitochondria-targeting cancer phototherapy, high fluence low-power laser irradiation (HF-LPLI) induces mitochondrial superoxide anion burst, resulting in oxidative damage to tumor cells. In this study, we further explored the immunological effects of HF-LPLI-induced apoptotic tumor cells. When macrophages were co-incubated with apoptotic cells induced by HF-LPLI, we observed the increased levels of TNF-α secretion and NO production in macrophages. Further experiments showed that NF-κB was activated in macrophages after co-incubation with HF-LPLI-induced apoptotic cells, and inhibition of NF-κB activity by pyrrolidinedithiocarbamic acid (PDTC) reduced the elevated levels of TNF-α secretion and NO production. These data indicate that HF-LPLI-induced apoptotic tumor cells induce the secretion of pro-inflammatory cytokines in macrophages, which may be helpful for better understanding the biological effects of cancer phototherapy.

Background: Squamous cell carcinoma (SCC) is a common skin cancer and its treatment is still a challenge. Although topical photodynamic therapy (PDT) is effective for treating in situ and superficial SCC, the effectiveness of topical ALA delivery to thick SCC can be limited by its bioavailability. Polylactic-co-glycolic acid nanopartieles (PLGA NPs) might provide a promising ALA delivery strategy. The aim of this study was to evaluate the efficacy of ALA PLGA NPs PDT for the treatment of cutaneous SCC in a mouse model. Methods: ALA loaded PLGA NPs were prepared and characterized. The therapeutic efficacy of ALA PLGA NP mediated PDT in treating UV-induced cutaneous SCC in the mice model were examined. Results: In vivo study showed that ALA PLGA NPs PDT were more effective than free ALA of the same concentration in treating mouse cutaneous SCC. Conclusion: ALA PLGA NPs provides a promising strategy for delivering ALA and treating cutaneous SCC.

Neuronal cells play very important role on metabolism regulation and mechanism control, so cell number is a fundamental determinant of brain function. Combined suitable cell-labeling approaches with recently proposed three-dimensional optical imaging techniques, whole mouse brain coronal sections can be acquired with 1-μm voxel resolution. We have developed a completely automatic pipeline to perform cell centroids detection, and provided three-dimensional quantitative information of cells in the primary motor cortex of C57BL/6 mouse. It involves four principal steps: i) preprocessing; ii) image binarization; iii) cell centroids extraction and contour segmentation; iv) laminar density estimation. Investigations on the presented method reveal promising detection accuracy in terms of recall and precision, with average recall rate 92.1% and average precision rate 86.2%. We also analyze laminar density distribution of cells from pial surface to corpus callosum from the output vectorizations of detected cell centroids in mouse primary motor cortex, and find significant cellular density distribution variations in different layers. This automatic cell centroids detection approach will be beneficial for fast cell-counting and accurate density estimation, as time-consuming and error-prone manual identification is avoided.

The gas NO is a ubiquitous intercellular messenger that modulates a wide range of physiological and pathophysiological functions. But few studies were made to study the role of NO in the Ca²⁺ release in dorsal root ganglion (DRG) neurons by confocal microscopy. Thus the objective of this study was to assess if NO has a role in Ca²⁺ signaling in DRG neurons using confocal microscopy combined with special fluorescence probe Fluo-3/AM. A 100 μM concentration of the NO donors (Sodium Nitroprusside, Dihydrate, SNP) and NO synthase inhibitor (NG-Monomethyl-L-arginine, Monoacetate salt, L-NMMA) was used in the study. Results showed that the fluorescence intensity increased rapidly after injecting SNP, which indicated that SNP could enhance intracellular Ca²⁺ release. And the fluorescence intensity shrank gradually with time and kept at a low level for quite a long period after loading with L-NMMA which indicated that L-NMMA could block intracellular Ca²⁺ release. All these results demonstrated that NO was involved in the regulation of intracellular Ca²⁺ release in the DRG neurons.

Downregulation of brain-derived neurotrophic factor (BDNF) in the hippocampus occurs early in the progression of Alzheimer’s disease (AD). Since BDNF plays a critical role in neuronal survival and dendrite growth, BDNF upregulation may contribute to rescue dendrite atrophy and cell loss in AD. Low-level laser therapy (LLLT) has been demonstrated to regulate neuronal function both in vitro and in vivo. In the present study, we found that LLLT rescued neurons loss and dendritic atrophy via the increase of both BDNF mRNA and protein expression. In addition, dendrite growth was improved after LLLT, characterized by upregulation of PSD95 expression, and the increase in length, branching, and spine density of dendrites in hippocampal neurons. Together, these studies suggest that upregulation of BDNF with LLLT can ameliorate Aβ-induced neurons loss and dendritic atrophy, thus identifying a novel pathway by which LLLT protects against Aβ-induced neurotoxicity. Our research may provide a feasible therapeutic approach to control the progression of Alzheimer’s disease.

Optical coherence tomography (OCT) has been widely employed as non-invasive 3D imaging diagnostic instrument, particularly in the field of ophthalmology. Although OCT has been approved for use in clinic in USA, Europe and Asia, international standardization of this technology is still in progress. Validation of OCT imaging capabilities is considered extremely important to ensure its effective use in clinical diagnoses. Phantom with appropriate test targets can assist evaluate and calibrate imaging performance of OCT at both installation and throughout lifetime of the instrument. In this paper, we design and fabricate a physical model eye with 3D resolution test targets to characterize OCT imaging performance. The model eye was fabricated with transparent resin to simulate realistic ophthalmic testing environment, and most key optical elements including cornea, lens and vitreous body were realized. The test targets which mimic USAF 1951 test chart were fabricated on the fundus of the model eye by 3D printing technology. Differing from traditional two dimensional USAF 1951 test chart, a group of patterns which have different thickness in depth were fabricated. By measuring the 3D test targets, axial resolution as well as lateral resolution of an OCT system can be evaluated at the same time with this model eye. To investigate this specialized model eye, it was measured by a scientific spectral domain OCT instrument and a clinical OCT system respectively. The results demonstrate that the model eye with 3D resolution test targets have the potential of qualitatively and quantitatively validating the performance of OCT systems.

Compact and discriminative feature extraction is a challenging task for infrared face recognition. In this paper, we propose an infrared face recognition method using Partial Least Square (PLS) regression on Discrete Cosine Transform (DCT) coefficients. With the strong ability for data de-correlation and compact energy, DCT is studied to get the compact features in infrared face. To dig out discriminative information in DCT coefficients, class-specific One-to-Rest Partial Least Squares (PLS) classifier is learned for accurate classification. The infrared data were collected by an infrared camera Thermo Vision A40 supplied by FLIR Systems Inc. The experimental results show that the recognition rate of the proposed algorithm can reach 95.8%, outperforms that of the state of art infrared face recognition methods based on Linear Discriminant Analysis (LDA) and DCT.

Texture analysis plays a crucial role in identifying objects or regions of interest in an image. It has been applied to a variety of medical image processing, ranging from the detection of disease and the segmentation of specific anatomical structures, to differentiation between healthy and pathological tissues. Second harmonic generation (SHG) microscopy as a potential noninvasive tool for imaging biological tissues has been widely used in medicine, with reduced phototoxicity and photobleaching. In this paper, we clarified the principles of texture analysis including statistical, transform, structural and model-based methods and gave examples of its applications, reviewing studies of the technique. Moreover, we tried to apply texture analysis to the SHG images for the differentiation of human skin scar tissues. Texture analysis method based on local binary pattern (LBP) and wavelet transform was used to extract texture features of SHG images from collagen in normal and abnormal scars, and then the scar SHG images were classified into normal or abnormal ones. Compared with other texture analysis methods with respect to the receiver operating characteristic analysis, LBP combined with wavelet transform was demonstrated to achieve higher accuracy. It can provide a new way for clinical diagnosis of scar types. At last, future development of texture analysis in SHG images were discussed.

We presented a novel dual-wavelength diffuse optical imaging system which can perform 2-D or 3-D imaging fast and high-sensitively for monitoring the dynamic change of optical parameters. A newly proposed lock-in photon-counting detection method was adopted for week optical signal collection, which brought in excellent property as well as simplified geometry. Fundamental principles of the lock-in photon-counting detection were elaborately demonstrated, and the feasibility was strictly verified by the linearity experiment. Systemic performance of the prototype set up was experimentally accessed, including stray light rejection and inherent interference. Results showed that the system possessed superior anti-interference capability (under 0.58% in darkroom) compared with traditional photon-counting detection, and the crosstalk between two wavelengths was lower than 2.28%. For comprehensive assessment, 2-D phantom experiments towards relatively large dimension model (diameter of 4cm) were conducted. Different absorption targets were imaged to investigate detection sensitivity. Reconstruction image under all conditions was exciting, with a desirable SNR. Study on image quality v.s. integration time put forward a new method for accessing higher SNR with the sacrifice of measuring speed. In summary, the newly developed system showed great potential in promoting detection sensitivity as well as measuring speed. This will make substantial progress in dynamically tracking the blood concentration distribution in many clinical areas, such as small animal disease modeling, human brain activity research and thick tissues (for example, breast) diagnosis.

Two-photon excited fluorescence (TPEF) microscopy, has become a powerful tool for imaging unstained tissue samples at subcellular level in biomedical research. The purpose of this study was to determine whether TPEF imaging of histological sections without H-E staining can be used to identify the boundary between normal pancreas and pancreatic metastasis from renal cell carcinoma (RCC). The typical features such as the significant increase of cancerous nests, the absence of pancreatic ductal, the appearance of cancer cells were observed to present the boundary between normal pancreas and pancreatic metastasis from RCC. These results correlated well with the corresponding histological outcomes. With the advent of clinically miniaturized TPEF microscopy and integrative endoscopy, TPEF microscopy has the potential application on surgical location of pancreatic metastasis from RCC in the near future.

The collagen signature in colorectal submucosa is changed due to remodeling of the extracellular matrix during the malignant process and plays an important role in noninvasive early detection of human colorectal cancer. In this work, multiphoton microscopy (MPM) was used to monitor the changes of collagen in normal colorectal submucosa (NCS) and cancerous colorectal submucosa (CCS). What’s more, the collagen content was quantitatively measured. It was found that in CCS the morphology of collagen becomes much looser and the collagen content is significantly reduced compared to NCS. These results suggest that MPM has the ability to provide collagen signature as a potential diagnostic marker for early detection of colorectal cancer.

Fibroadenoma (FA) is the most common benign tumor of the female breast and several studies have reported that women with it have increased risk of breast cancer. While the ductal carcinoma in situ (DCIS) is a very early form of breast cancer. Thus, early detections of FA and DCIS are critical for improving breast tumor outcome and survival. In this paper, we use multiphoton microscopy (MPM) to obtain the high-contrast images of fresh, unfixed, unstained human breast specimens (normal breast tissue, FA and DCIS). Our results show that MPM has the ability to identify the characteristics of FA and DCIS including changes of duct architecture and collagen morphology. These results are consistent with the histological results. With the advancement of MPM, the technique has potential ability to serve as a real-time noninvasive imaging tool for early detection of breast tumor.

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the prevalent skin cancers, which have a quite high incidence in the white race. In recent years, however, their incidences have been increasing in the yellow race, resulting in a great threat to the public health. According to researches, chronics UVB irradiation (280nm~320nm) is the major culprit of skin cancer in humans. In our study, the model of UVB induced skin cancer was established firstly. Optical coherence tomography (OCT) combined with the histopathology was exploited to monitor the morphologic and histological changes of the process of UVB induced skin cancer. Meanwhile, this canceration process was systematically studied and analyzed from the perspective of tissue optics. The attenuation coefficient (μ_t) has a rising trend in the epidermis, but which shows a downward trend in the dermis. The results are conducive to understand the process of UVB-induced skin cancer and further be able to provide a reference for medical researchers.

A photoacoustic tomography imaging system using a low-coherence interferometer with rapid detection of phase modulation was designed, fabricated, and tested for biologic imaging. A noncontact probing technique was applied to improve the practicability of the system. The technique is experimentally verified by the image of a simulated tissue sample and the blood vessels within a mouse ear flap (pinna) in vivo. The system’s axial and lateral resolutions are evaluated at 45 and ~15 μm, respectively. The system’s imaging depth is 1mm in a special phantom. The results show that the system has the feasibility to be used as a photoacoustic tomography imaging method, and it may provide a kind of possibility of noncontact real-time PAT.

To evaluate the effects of red Light-Emitting Diodes on elbow extensor and flexor strength and the recovery of exercise induced fatigue, the torque values from the isokinetic dynamometer as well as biochemistry parameters were used as outcome measures. A randomized double-blind placebo-controlled crossover trial was performed with twenty male young tennis athletes. Active LED therapy (LEDT, with wavelength 625nm, 10 minutes total irradiation time, irradiated area amount to 30cm², and 900J of total energy irradiated) or an identical placebo was delivered under double-blinded conditions to the left elbow just before exercise. The isokinetic muscle strength was measured immediately after irradiation. The blood lactate levels were sampled pre-exercise and post-exercise. The peak torque values of elbow extensor strength were significantly different between two groups. As in elbow flexor strength, the difference of peak torque was not significant. The blood lactate concentration of LEDT group post-exercise was significantly lower than those of placebo group. The results indicate that 625nm LED therapy is effective in preventing muscle fatigue as it can significantly reduce peak torque value of elbow extensors and blood lactate concentration. It has no effect on the strength of left elbow flexor or backhand performance in tennis.

Photodynamic therapy (PDT) is a clinically approved treatment that was applied to oncology , dermatology, and ophthalmology. Reactive oxygen species (ROS) play a important role in the efficacy of PDT. Online monitoring of reactive oxygen species is the key to understand effect of PDT treatment. We used Fluorescence probes DPBF and luminescent probe luminal to measure the ROS in cells. And we revaluate the relationship between the amount of light and cell survival. There is strongly correlated between the amount of light and cell kill.

We present a full-range Fourier domain polarization-sensitive optical coherence tomography technique which is able to obtain images of retardance, fast optical axis and intensity of sample. In this technique, the sinusoidal phase modulation is introduced into the spectral interferograms while the probe beam scans over the sample (B-scan). Then the complex horizontal and vertical signals are reconstructed by demodulation. By the Fourier transformation of the two interferograms, the full range images are obtained. Herein, the typical linear phase modulation is modified to sinusoidal phase modulation, which improves the system tolerance of sample movements and avoids sensitivity fall-off along the transverse scan. Furthermore, the images are obtained through the recombination of the horizontal and vertical polarization beam components acquired by a single camera, which avoids the problems of synchronous control and alignments in the situation of two cameras.

Integrin αvβ3 receptors are expressed on activated endothelial cells during neovascularization to maintain tumor growth, so they become hot research tagets in cancer diagnosis. Peptides possess several attractive features when compared to protein and small molecule, such as small size and high structural compatibility with target proteins. Efficient design of high-affinity peptide ligands to Integrin αvβ3 receptors has been an important problem. Designed peptides in silico provide a valuable and high-selectivity peptide, meanwhile decrease the time of drug screening. In this study, we design peptide which can bind with integrin αvβ3 via computer, and then synthesis near infrared fluorescent probe. The characterization of this near infrared fluorescent probe was detected by UV. To investigate the tumor cell targeting of this probe, it was labeled with visible fluorescent dye Rhodamine B (RhB) for microscopy. To evaluate the targeting capability of this near infrared fluorescent probe, mice bearing integrin αvβ3 positive tumor xenografts were used. In vitro cellular experiments indicated that this probe have a clear binding affinity to αvβ3-positive tumor cells. In vivo experiments confirmed the receptor binding specificity of this probe. The peptide of computational design can bind with integrin αvβ3. Combined peptide near-infrared fluorescent probe with imaging technology use for clinical and tumor diagnosis have a greater development in future.

A major problem in cancer treatment is the development of resistance to chemotherapeutic agents in tumor cells. Detection of effective prognostic biomarkers and targets are of crucial importance to the management of individualized therapies. However, quantitative analysis of the drug resistance gene had been difficult because of technical limitations. In this study, we designed and used a special hairpin deoxyribonucleic acid (DNA), which served as a beacon for detecting human drug resistance indicater. Upon hybridizing with the target mRNA, the hairpin DNA modified gold nanoparticle beacons (hDAuNP beacons) release the fluorophores attached at 5’end of the oligonucleotide sequence. The fluorescence properties of the beacon before and after the hybridization with the complementary DNA were confirmed in vitro. The hDAuNP beacons could be taken up by living cells with low inherent cytotoxicity and higher stability. hDAuNP beacon imaged by confocal laser scanning microscopy to detect the resistance gene expression. The detected fluorescence in MCF7and MCF7/ADR cells correlates with the specific drug resistance gene expression, which is consistent with the result from Q-PCR. Thus, this approach overcame many of the challenges of previous techniques by creating highly sensitive and effective intracellular probes for monitoring gene expression.

Gastric cancer is one of the leading causes of cancer death in the world due to its high morbidity and mortality. Hyperspectral imaging (HSI) is an emerging, non-destructive, cutting edge analytical technology that combines conventional imaging and spectroscopy in one single system. The manuscript has investigated the application of near-infrared hyperspectral imaging (900-1700 nm) (NIR-HSI) for gastric cancer detection with algorithms. Major spectral differences were observed in three regions (950-1050, 1150-1250, and 1400-1500 nm). By inspecting cancerous mean spectrum three major absorption bands were observed around 975, 1215 and 1450 nm. Furthermore, the cancer target detection results are consistent and conformed with histopathological examination results. These results suggest that NIR-HSI is a simple, feasible and sensitive optical diagnostic technology for gastric cancer target detection with chemometrics.

Adaptive optics is implemented in a confocal scanning fluorescence microscope with wavefront sensorless scheme. Using the image sharpness as the optimization metric, aberration correction is performed to compensate both system- and specimen-induced aberrations by using stochastic parallel gradient descent algorithm based upon Zernike polynomial modes. In vivo vascular imaging of mice ear is completed and the results revealed the improved signal and resolution leading to in substantially enhanced image contrast with aberration correction which allowed us to detect clearer vasculature structures.

Molecular characterization of semen that can be used to provide an objective diagnosis of semen quality is still lacking. Raman spectroscopy measures vibrational modes of molecules, thus can be utilized to characterize biological fluids. Here, we employed Raman spectroscopy to characterize and compare normal and abnormal semen samples in the fingerprint region (400-1800cm^-1). Multivariate analysis methods including principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were used for spectral analysis to differentiate between normal and abnormal semen samples. Compared with PCA-LDA analysis, PLS-DA improved the diagnostic results, showing a sensitivity of 77% and specificity of 73%. Furthermore, our preliminary quantitative analysis based on PLS algorithm demonstrated that spermatozoa concentration were relatively well predicted (R²=0.825). In conclusion, this study demonstrated that micro-Raman spectroscopy combined with multivariate methods can provide as a new diagnostic technique for semen analysis and differentiation between normal and abnormal semen samples.

Speckle noise is a key factor that can influence the image quality of optical coherence tomography (OCT). The averaging of multiple B-scans can effectively suppress the speckle noise. Because of the sample motion, the images have to be exactly aligned before averaging. In this paper, we propose a new method for OCT image registration that combines global and local registration. The method is able to align the large global displacements in axial and lateral directions, as well as local displacements caused by non-linear deformation between images. Compared with other OCT image registration methods, our method improves the signal-to-noise ratio and contrast-to-noise ratio.

Surface-enhanced Raman scattering (SERS) spectroscopy combined with membrane electrophoresis (ME) was firstly employed to detect albumin variation in type II diabetic development. Albumin was first purified from human serum by ME and then mixed with silver nanoparticles to perform SERS spectral analysis. SERS spectra were obtained from blood albumin samples of 20 diabetic patients and 19 healthy volunteers. Subtle but discernible changes in the acquired mean spectra of the two groups were observed. Tentative assignment of albumin SERS bands indicated specific structural changes of albumin molecule with diabetic development. Meanwhile, PCA-LDA diagnostic algorithms were employed to classify the two kinds of albumin SERS spectra, yielding the diagnostic sensitivity of 90% and specificity of 94.7%. The results from this exploratory study demonstrated that the EM-SERS method in combination with multivariate statistical analysis has great potential for the label-free detection of albumin variation for improving type II diabetes screening.

A surface-enhanced Raman spectroscopy (SERS) approach was utilized for urine biochemical analysis with the aim to develop a label-free and non-invasive optical diagnostic method for esophagus cancer detection. SERS spectrums were acquired from 31 normal urine samples and 47 malignant esophagus cancer (EC) urine samples. Tentative assignments of urine SERS bands demonstrated esophagus cancer specific changes, including an increase in the relative amounts of urea and a decrease in the percentage of uric acid in the urine of normal compared with EC. The empirical algorithm integrated with linear discriminant analysis (LDA) were employed to identify some important urine SERS bands for differentiation between healthy subjects and EC urine. The empirical diagnostic approach based on the ratio of the SERS peak intensity at 527 to 1002 cm^-1 and 725 to 1002 cm^-1 coupled with LDA yielded a diagnostic sensitivity of 72.3% and specificity of 96.8%, respectively. The area under the receive operating characteristic (ROC) curve was 0.954, which further evaluate the performance of the diagnostic algorithm based on the ratio of the SERS peak intensity combined with LDA analysis. This work demonstrated that the urine SERS spectra associated with empirical algorithm has potential for noninvasive diagnosis of esophagus cancer.

The use of normal Raman (NR) spectroscopy and surface enhanced Raman scattering (SERS) spectroscopy to analyze the biochemical information of human serum proteins and hence distinguish between normal and primary hepatic carcinoma (PHC) serum samples was investigated. The serum samples were obtained from patients who were clinically diagnosed with PHC (n=20) and healthy volunteers (n=20). All spectra were collected in the spectral range of 400-1800 cm^-1 and analyzed through the multivariate statistical methods of principal component analysis (PCA). The results showed that both NR and SERS combined with PCA had good performance in distinguishing the human serum proteins between PHC patients and healthy volunteers with high sensitivity and specificity of 100%. And we can get more detail information of component and conformation of human serum proteins by considering NR and SERS spectrum. Our results support the concept again that serum protein Raman and SERS spectroscopy combined with PCA analysis both can become noninvasive and rapid diagnostic tools to detect the primary hepatic carcinoma.

Fluorescence molecular tomography (FMT) gains increasing interests in deep tissue imaging. Here we report a novel FMT system setup with full angel projections. In this system, a tungsten-halogen lamp is applied as illumination, while a scientific complementary metal oxide semiconductor (sCMOS) is used as a detecting device. With a unique line-pattern illumination and a high sensitivity sCMOS, our FMT system can complete data acquisition over 36 perspective angles along the animal within 10 minutes. We also employ a novel transparent animal bed, which is suitable to hold the animal for long time experiments. Both phantom and in vivo animal experiments have been studied, and our results demonstrate this FMT system has a great potential for small animal study. In addition, our design allows this FMT system to be easily applied in either stand-alone fluorescent systems or combined with other molecular imaging methods.

We developed a prototype dual-modal ocular imaging system integrating optical-resolution photoacoustic microscopy and high-frequency ultrasound imaging modalities. This system can perform high-resolution ocular imaging from the anterior region down to the fundus area. The novel system successfully imaged the murine eyes in vivo, including iris, lens, retina, and retinal pigment epithelium. Our results demonstrated that this system has a great potential in the diagnosis of ophthalmic diseases.

A compact, high-speed line scanning quasi-confocal ophthalmoscope (LSO) for retina imaging is presented in this paper. By using a line beam to illuminate the retina, meanwhile a linear array sensor is used for imaging the retina, the LSO system significantly reduces the size, complexity, and cost comparing to a conventional confocal scanning laser ophthalmoscope (CSLO). With only one moving scanner to provide raster scanning of the line beam of the retina, the imaging frequency achieves 160 Hz and the lateral resolution is nearly 10 μm for 1024×330 pixels imaging mode. Preliminary experiments are performed for imaging the macula, the optic nerve head and other targets, providing high resolution and high speed videos of human retina.

The combination of diagnostics and therapeutics is growing rapidly in cancer treatment. Here, using upconversion nanoparticles coated with chitosan conjugated with a targeting molecule and loaded with indocyanine green (ICG), an excitation-selectable nanoprobe with highly integrated functionalities, including the emission of visible and near-infrared (NIR) light, strong optical absorption in the NIR region and high photostability was developed. After injected in mice, the nanoprobes targeted to the tumor vascular system. NIR lasers (980 and 808 nm) were then selectively applied to the mice. The results show that, the emitted upconversion fluorescence and NIR fluorescence can be used in a complementary manner for high signal/noise ratio and sensitive tumor imaging for more precise tumor localization; Highly effective photothermal therapy can be realized using 808 nm laser irradiation. The upconversion fluorescence at 654 nm is useful for monitoring treatment effect during thermal therapy. In summary, using the nanoprobes, outstanding therapeutic efficacy could be realized and the nanofabrication strategy would highlight the promise of upconversion nanoparticles in cancer theranostics.

Microwave-induced thermoacoustic imaging (TAI) has attracted considerable interest as a promising imaging modality. Previous studies show that TAI has great potential for use in breast tumor detection with high contrast and high spatial resolution, nevertheless it requires high energy density and possesses small field of view (FOV). In this paper, a ultrashort microwave pulse (USMP) TAI system was employed for quality imaging with much less energy density required , and simultaneously, large enough FOV was obtained to cover the whole breast. The experimental results clearly demonstrate that the new USMP TAI system can be used for three-dimensional (3-D) localization of deep breast tumors with low microwave radiation dose over the whole breast.

Photoacoustic imaging is a fast growing imaging technology depending on its high optical resolution of optics while taking the advantage of the high penetration depth of ultrasound. In this paper, we demonstrate the new progress in the photoacoustic imaging. Atherosclerosis is characterized by a progressive build-up of lipid in the arterial wall, which is known as plaque. Histological studies demonstrate that the primary cause of acute cardiovascular events is the rupture of atherosclerotic plaques. Lipid and inflammation within the plaque are related to influence the propensity of plaques to disrupt. Photoacoustic intravascular tomography (IVPAT) holds a great advantage in providing comprehensive morphological and functional information of plaques. Lipid relative concentration maps of atherosclerotic aorta were obtained and compared with histology. Furthermore, by selectively targeting the intravascular inflammatory cytokines, IVPAT is also capable of mapping the inflamed area and determining the degree of inflammation.

Micro-Raman spectroscopy is widely used for non-invasive tissue diagnosis and detection, as it provides detailed information about biomolecular composition, structure, and interaction of tissue. In this work, micro-Raman spectroscopy was used to investigate non-cancerous and cancerous nasopharyngeal tissues. The obtained nasopharyngeal tissue samples in vitro are divided into two groups: cancerous (n=12, undifferentiated non-keratinizing carcinomas) and non-cancerous (n=10, 7 chronic inflammations, 2 lymphomas and 1 lymphocytosis). Firstly, we analyzed the Raman spectra in the fingerprint (FP, 400-1800cm^-1) region acquired. Preliminary results showed that there are some spectral differences in different pathological conditions. Furthermore, Raman spectra from cancerous and non-cancerous nasopharyngeal tissue in the high wavenumber region (HW, 2800-3100cm^-1) were also reported for the first time. After detailed analysis, we achieved significant differences in Raman bands at 2854, 2874, 2934, and 3067cm^-1 between cancerous and non-cancerous nasopharyngeal tissues. This study demonstrates that both fingerprint and high wavenumber regions of micro-Raman spectroscopy have the potential for the early detection of nasopharyngeal carcinomas.