Blood thinners: antithrombin-independent effects of low-molecular-weight heparin on fibrin fiber mechanics

Understanding the mechanics of individual fibrin fibers is relevant to the pathophysiology of various thromboembolic diseases such as deep vein thrombosis (DVT), pulmonary embolism, and ischemic stroke. Our study aims to explore the effects of heparins independent of their primary effect in ending the coagulation cascade. Specifically, our study explores antithrombin-independent effects on the mechanics, diameter, and extensibility of single fibrin fibers treated with various concentrations of the low-molecular-weight-heparin enoxaparin. We use atomic force microscopy and Euler-Lagrange beam mechanics to create stress-strain models of individual fibers, providing useful information on enoxaparin’s effect on fiber behavior. Our results quantitively show that therapeutic doses of enoxaparin increase fiber diameter, thus decreasing the fiber’s Young modulus. There are also visible qualitative changes with both therapeutic and prophylactic doses of enoxaparin. These results can guide future studies on the effects of using anticoagulants in treating thromboembolic disease.