Assessment of Cannabidiol Effects on Whole-Blood Coagulation Dynamics Using a Novel Point-of-Care Radial Expansion Assay

Leah K. DuBose
FAMU - FSU College of Engineering

Co-authors: Rojan Saghian¹, Domenica Jaramillo¹, Oluwadara Soremi¹, Leah DuBose¹, Jingjiao Guan¹, Kyle Smith², Zixiang Leonardo Liu, PhD, Assistant Professor^1,2
1FAMU-FSU College of Engineering, ²Florida State University

Statement of the problem (Objectives): The surging incidence of cannabinoid-associated coagulopathy (CAC) underscores a critical diagnostic gap: the inability of current paradigms to evaluate the complex interplay between cannabinoid exposure and hemostatic stability.

Background: Cannabinoids, including cannabidiol (CBD), are widely used by patients receiving anticoagulant therapies, yet their effects on hemostasis remain poorly understood. While case reports and drug-interaction studies have suggested potential associations between cannabinoid exposure and altered bleeding risk, experimental evidence describing the direct effects of cannabinoids on blood coagulation is limited and often conflicting. Current coagulation assays primarily assess isolated plasma coagulation pathways and may not fully capture the integrated rheological and clotting behavior of whole blood.

Methods: To investigate the effects of cannabidiol (CBD) on whole-blood coagulation, we employed a miniaturized Radial Flow Assay (RFA), a point-of-care platform that quantifies temporal changes in blood spreading area as a surrogate measure of viscosity and coagulation dynamics under low-shear conditions. Experiments were conducted using citrated whole blood (3.2% w/v sodium citrate) and heparinized whole blood (3.5 USP units/mL heparin). CBD was evaluated across physiologically relevant concentrations, and coagulation responses were assessed using radial expansion area. RFA measurements were compared against established coagulation assays, including a lateral flow assay (LFA) for recalcified blood and Activated Clotting Time (ACT) testing for heparinized blood.

Results: The RFA detected dose-dependent coagulation responses during recalcification of citrated whole blood, confirming assay sensitivity to coagulation-induced changes in blood spreading dynamics. Across physiologically relevant concentrations, CBD produced no significant changes in radial expansion behavior of recalcified blood. Consistent with these findings, ACT measurements of heparinized blood following protamine neutralization showed no significant differences between CBD-treated and control groups.

Conclusions: CBD produced no measurable changes in whole-blood coagulation, indicating minimal direct effects on secondary hemostasis. Differences observed between RFA and conventional coagulation assays suggest that clot microstructure, in addition to fibrin quantity, contributes to assay-specific responses. These findings support the hypothesis that cannabinoid-associated coagulopathy may be driven predominantly by platelet dysfunction and impaired shear-induced platelet aggregation rather than alterations in coagulation factor activity. Ongoing studies using physiologically relevant microfluidic models will evaluate the effects of cannabinoids on platelet mechanobiology and thrombus formation under high-shear flow conditions.