Significance: Tumor heterogeneity poses a challenge for the chemotherapeutic treatment of cancer. Tissue dynamics spectroscopy captures dynamic contrast and can capture the response of living tissue to applied therapeutics, but the current analysis averages over the complicated spatial response of living biopsy samples.
Aim: To develop tissue dynamics spectroscopic imaging (TDSI) to map the heterogeneous spatial response of tumor tissue to anticancer drugs.
Approach: TDSI is applied to tumor spheroids grown from cell lines and to ex vivo living esophageal biopsy samples. Doppler fluctuation spectroscopy is performed on a voxel basis to extract spatial maps of biodynamic biomarkers. Functional images and bivariate spatial maps are produced using a bivariate color merge to represent the spatial distribution of pairs of signed drug-response biodynamic biomarkers.
Results: We have mapped the spatial variability of drug responses within biopsies and have tracked sample-to-sample variability. Sample heterogeneity observed in the biodynamic maps is associated with histological heterogeneity observed using inverted selective-plane illumination microscopy.
Conclusion: We have demonstrated the utility of TDSI as a functional imaging method to measure tumor heterogeneity and its potential for use in drug-response profiling.
Early stage porcine parthenogenetic embryos were evaluated for metabolic activity using a biodynamic microscope (BDM) that images dynamic light scattering using low-coherence digital holography. The microscope has a 45-deg illumination configuration that reduces specular background for the imaging of small translucent samples. The off-axis illumination is compatible with coherence-gated imaging because of volumetric light scattering in which the coherence plane is tilted at half the illumination angle in a three-dimensional tissue target. The BDM was used to profile the viability of porcine parthenotes with normal and with inhibited mitochondrial adenosine triphosphate (ATP) production using Doppler fluctuation spectroscopy. The ATP concentrations in the parthenotes, which are indicative of developmental potential, were validated by a conventional bioluminescence assay. Biodynamic classifications achieved ∼80 % accuracy correlating sample ATP treatment, providing a quick, label-free surrogate measurement to replace invasive metabolic assays as a candidate for evaluating quality of early embryos in the assisted reproductive technology setting.
Intracellular dynamics are dominated by active transport driven by energetic processes far from equilibrium. Cytoskeletal restructuring, membrane motions and molecular motors use GTP and ATP to drive directed transport that is quasi-one-dimensional with speeds from 10 nm/sec to 10 microns/sec and persistence times tp as large as several seconds. Light scattering under these conditions can be in the lifetime-broadened Doppler shift regime as opposed to a random diffusive regime. The isotropic distribution of 1D transport within cells and tissues produces broad-band signatures that do not produce specific Doppler spectral peaks, but produce Doppler spectral edges that can be related to the mean squared speeds inside cells. The wDtp = 1 product provides a natural dividing line between the Doppler and the diffusive regimes, with a broad cross-over range into which many tissue-based light scattering processes fall. In this talk, I will show how the intracellular Doppler character of dynamic light scattering is derived and modeled, and provide experimental support from biodynamic imaging. Biodynamic imaging uses low-coherence digital holography to capture dynamic spectra in three dimensions from living tissue samples. Biodynamic imaging, based on changes in intracellular dynamics caused by applied therapeutics or changing environments, is expanding into multiple applications, including the selection of chemotherapy for personalized cancer care, screening of potential new therapeutics, and the selection of embryos for artificial reproductive technology. I will give an overview of these applications, describing how changes in biophysical behavior provide actionable biomarkers for clinical applications.
Biodynamic imaging uses coherence-gated dynamic light scattering to create three dimensional maps of intracellular dynamics in living tissue biopsies. The technique is sensitive to changes in intracellular dynamics dependent on the mechanism of action (MoA) of therapeutics applied in vitro to the living samples. A preclinical trial in the assessment of chemotherapeutic response of dogs with B-cell lymphoma to the doxorubicin-based therapy CHOP has been completed using biodynamic imaging. The trial enrolled 19 canine patients presenting with non-Hodgkin’s B-cell lymphoma. Biopsies were acquired through surgery or through needle cores. The time-varying power spectrum of scattered light after drugs are applied ex vivo to the biopsies represent biodynamic biomarkers that are used in machine learning algorithms to predict the patient clinical outcome. Two distinct phenotypes emerged from the analysis that correlate with patient drug resistance or sensitivity. Cross validation of the algorithms perform with an accuracy of 90% in the prediction of dogs that will respond to treatment. Biodynamic imaging has the potential to help select chemotherapy for personalized cancer care.
Biodynamic imaging (BDI) is capable of capturing the intracellular dynamics of blastocysts within a relatively short time. Spectroscopic signatures of embryos in the 0.01 Hz - 1 Hz range display responses to external factors before morphology changes take place. Viability evaluation is consistent with results from other non-invasive methods. Biodynamic imaging is a potential tool for selecting high quality embryos in clinical IVF practices.
Biodynamic imaging is a novel 3D optical imaging technology based on short-coherence digital holography that measures intracellular motions of cells inside their natural microenvironments. Here both common-path and Mach-Zehnder designs are presented. Biological tissues such as tumor spheroids and ex vivo biopsies are used as targets, and backscattered light is collected as signal. Drugs are applied to samples, and their effects are evaluated by identifying biomarkers that capture intracellular dynamics from the reconstructed holograms. Through digital holography and coherence gating, information from different depths of the samples can be extracted, enabling the deep-tissue measurement of the responses to drugs.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.