Anomalous mechanics of Zn <sup>2+</sup> -modified fibrin networks
Jing Xia, Li‐Heng Cai, Huayin Wu, F. C. MacKintosh, David A. Weitz
Abstract
Significance Fibrin forms a three-dimensional network in blood clots during hemostasis that must be strong enough to stop bleeding yet flexible enough to withstand pressure variations of arterial flow. During clotting, activated platelets release Zn 2+ whose effect on the structure and mechanics of fibrin gels is poorly understood. We show that Zn 2+ unexpectedly reduces fibrin gel stiffness even though it induces bundling that coarsens the network. This results from weak interactions between the fibrils that make up the bundle, leading to a loose coupling that results in a softer network. These results provide important insight into the impact of Zn 2+ on the behavior of blood clots and represent a different class of network that becomes weaker even with increasing bundle thickness.