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Updated: Dec 11, 2025
Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Design of a Microfluidic Bleeding Chip to Evaluate Antithrombotic Agents for Use in COVID-19 Patients
Hari Hara Sudhan Lakshmanan1, Adity A Pore2, Tia C L Kohs1
1Department of Biomedical Engineering, Oregon Health & Science University, 3303 SW Bond Ave; CH13B, Portland, OR 97239 USA.
Insights
A new microfluidic "bleeding chip" was developed to assess antithrombotic therapies for COVID-19. This tool models hemostatic plug formation in vitro, aiding the development of treatments to prevent thrombosis and reduce mortality.
Area of Science:
- Biomedical Engineering
- Hematology
- Virology
Background:
- COVID-19 mortality is linked to cytokine release and blood coagulation.
- Effective interventions are needed to prevent thrombosis in COVID-19 patients.
- Limited in vitro methods exist for evaluating anticoagulant effects on hemostasis.
Purpose of the Study:
- To design and present a microfluidic "bleeding chip" device.
- To evaluate the effects of antithrombotic therapies on hemostatic plug formation in vitro.
Main Methods:
- A microfluidic device with two orthogonal channels was designed.
- A "bleeding channel" with collagen-coated pillars models hemostasis at injury sites.
- Human whole blood was perfused through the device.
Main Results:
- Platelet adhesion and aggregation occurred at the pillars.
- Hemostatic plug formation and occlusion of the bleeding channel were observed.
- The device successfully modeled in vitro hemostasis.
Conclusions:
- A microfluidic device can model hemostatic plug formation.
- This tool has potential for assessing anticoagulant therapies.
- Development of such tools is crucial for managing COVID-19 thrombotic complications.
Introduction:
Interventions that could prevent thrombosis, clinical decompensation, and respiratory compromise in patients with novel coronavirus disease (COVID-19) are key to decrease mortality rate. Studies show that profound cytokine release and excessive activation of blood coagulation appear to be key drivers of COVID-19 associated mortality. Since limited in vitro methods exist for assessing the effects of anticoagulants on hemostasis, the development of novel therapies to safely prevent thrombosis in COVID-19 patients relies on preclinical animal models and early phase human trials. Herein we present the design of a microfluidic "bleeding chip" to evaluate the effects of antithrombotic therapies on hemostatic plug formation in vitro.
Methods:
The design of the microfluidic device consists of two orthogonal channels: an inlet that serves as a model blood vessel, and a bleeding channel to model hemostatic plug formation at sites of compromised endothelial barrier function. This is achieved by placing a series of 3 pillars spaced 10 μm apart at the intersection of the two channels. The pillars and bleeding channel are coated with the extracellular matrix protein collagen.
Results:
Perfusion of human whole blood through the microfluidic bleeding chip led to initial platelet adhesion and aggregation at the pillars followed by hemostatic plug formation and occlusion of the bleeding channel.
Conclusions:
Safe and effective mitigating agents are needed for treatment and prevention of thrombotic complications in COVID-19 patients. This simple microfluidic device holds potential to be developed into a tool for assessing the effects of anticoagulant therapy on hemostasis.
