Thrombosis remains a global health concern, necessitating research into its underlying mechanisms. Utilizing a high-speed bright-field microscope based on optical frequency-division multiplexing and microfluidics, we performed image-based single-cell profiling and temporal monitoring of circulating platelet aggregates that are the precursors to thrombosis. Our analysis encompassed 41 thrombosis patients, 110 COVID-19 patients, and 11 healthy individuals. By investigating the morphological changes of platelet aggregates under the influence of thrombosis, COVID-19, and COVID-19 vaccination, we observed distinct morphological alterations in platelet aggregates across different conditions, which shed light on the interplay between platelet aggregation and thrombotic events.
Vascular stenosis caused by atherosclerosis can lead to platelet activation and aggregation in thrombosis. However, the efficacy of antiplatelet drugs under stenosis is not well understood due to the lack of analytical tools. Here we demonstrate a new method combining optofluidic time-stretch quantitative phase microscopy and a 3D stenosis chip to enable highspeed, high-resolution, label-free imaging of circulating platelet aggregates under atherogenic flow conditions. Interestingly, our findings indicate that the proposed high-speed on-chip optofluidic imaging is a powerful tool for studying platelet biology, antiplatelet drug screening, and developing therapeutic strategies for patients with atherosclerotic diseases.
There is widespread concern about the safety of COVID-19 vaccinations related to platelet hyperactivity. However, their long-term influence on platelet activity remains unknown. We address this issue by applying a high-speed bright-field microscope based on optical frequency-division multiplexing and microfluidics for massive image-based analysis. We performed image-based single-cell profiling and temporal monitoring of circulating platelet aggregates in the blood samples of healthy human participants before and after they received three vaccination doses over a nearly one-year period. The results demonstrate no significant or persistent change in platelet activity after vaccine doses.
Vascular stenosis is a pathological hallmark of atherosclerosis, but its transient process is not well understood due to the lack of analytical tools to study it. Here we report spatiotemporally resolved observation of shear-induced platelet aggregation by combining a microfluidic on-chip stenosis model and optofluidic time-stretch microscopy. Our results indicate a synergistic effect of stenosis and agonists on platelet activation and aggregation. Particularly, an agonist, thrombin receptor activator peptide 6, causes preferential enhancement of platelet aggregation. Our findings are expected to deepen our understanding of stenosis-induced platelet aggregation and pave ways for developing effective antithrombotic therapeutics.
In COVID-19 therapy with artificial lungs such as extracorporeal membrane oxygenation (ECMO) machines, platelets in the extracorporeal circulation are often activated by their contact with the artificial materials, leading to the formation of blood clots followed by serious complications such as stroke and heart attack. However, anticoagulation and antithrombotic management is challenging due to the lack of testing tools to evaluate the circulation. Here we demonstrate real-time monitoring of thrombogenesis in the circulation of an ECMO-equipped goat with an intelligent platelet aggregate characterizer (iPAC), which is based on imaging flow cytometry and deep-learning-based analysis of numerous platelet aggregates in blood.
We present an extreme-throughput (>1 million cells per second) imaging flow cytometer with deep learning to achieve a highly simple, rapid, and cost-effective liquid biopsy for ex-vivo drug-susceptibility testing of leukemia. The drug resistance of leukemia cells was detected in whole blood with only 24-hour drug treatment without hemolysis or dilution, making the sample preparation extremely simple, rapid and cost-effective. Our method also accurately evaluated the drug susceptibility of white blood cells from untreated patients with acute lymphoblastic leukemia, holding great promise for affordable precision medicine.
Platelets participate in both physiological hemostasis and pathological thrombosis by forming aggregates activated by various agonists. However, it has been considered impossible to identify the stimuli and classify the aggregates. Here we present an intelligent method for classifying platelet aggregates by agonist type based on the combination of high-throughput imaging flow cytometry and a convolutional neural network. It morphologically identifies the contributions of different agonists to platelet aggregation with high accuracy. The method is a powerful tool for studying the underlying mechanism of platelet aggregation and is expected to develop a new class of clinical diagnostics and therapeutics.
KEYWORDS: In vivo imaging, Visualization, Digital image processing, Statistical analysis, Microscopy, Blood, Prostate cancer, Breast cancer, Spatial resolution, Microfluidics
According to WHO, approximately 10 million new cases of thrombotic disorders are diagnosed worldwide every year. In the U.S. and Europe, their related diseases kill more people than those from AIDS, prostate cancer, breast cancer and motor vehicle accidents combined. Although thrombotic disorders, especially arterial ones, mainly result from enhanced platelet aggregability in the vascular system, visual detection of platelet aggregates in vivo is not employed in clinical settings. Here we present a high-throughput label-free platelet aggregate detection method, aiming at the diagnosis and monitoring of thrombotic disorders in clinical settings. With optofluidic time-stretch microscopy with a spatial resolution of 780 nm and an ultrahigh linear scanning rate of 75 MHz, it is capable of detecting aggregated platelets in lysed blood which flows through a hydrodynamic-focusing microfluidic device at a high throughput of 10,000 particles/s. With digital image processing and statistical analysis, we are able to distinguish them from single platelets and other blood cells via morphological features. The detection results are compared with results of fluorescence-based detection (which is slow and inaccurate, but established). Our results indicate that the method holds promise for real-time, low-cost, label-free, and minimally invasive detection of platelet aggregates, which is potentially applicable to detection of platelet aggregates in vivo and to the diagnosis and monitoring of thrombotic disorders in clinical settings. This technique, if introduced clinically, may provide important clinical information in addition to that obtained by conventional techniques for thrombotic disorder diagnosis, including ex vivo platelet aggregation tests.
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