Structurally reassembled sunflower stem pith composite sponge for prehospital temporary emergency hemostasis

Abstract

Uncontrolled bleeding is a major cause of life-threatening conditions in emergency situations. Due to the limited blood absorption and procoagulant capacity, current hemostatic materials are often exhibit poor efficacy in treating uncontrolled bleeding. Although sunflower stem pith (SSP) has been been proven to facilitate blood coagulation, its practical application is restricted by anisotropic fluid absorption and low mass transfer efficiency. In this study, a novel SSP composite hemostaticmaterial was fabricated by disrupting the anisotropic structure of SSP and reassembling into an isotropic architecture within chitosan network, which exhibited controlled fluid absorption, shape memory and procoagulant properties. Among all samples, SSP composite sponge containing 1% chitosan (SSP+1% CS) showed the highest blood absorption capacity, with blood absorption ratio reaching 2009.8% (w/w) and blood absorption speed of 140.3 μg/(cm3·s), shape recovery ratio exceeding 95% in blood within 12 s. In vitro coagulation tests verified that SSP composite sponge reduced clotting time by more than 39% compared to gauze. SSP composite sponge significantly shortened the hemostatic time and reduced the blood loss in four animal bleeding models. In the rabbit femoral artery injury model, the hemostatic time of the SSP composite sponge was 71.8 s, which was 32% shorter than 105.6 s of the QuikClot® group; the blood loss of the SSPs group was 2.1 g, representing a 55% reduction relative to 4.68 g in the QuikClot® group. Cytotoxicity and hemocompatibility assays confirmed the excellent biocompatibility of SSP composite sponges. Consequently, SSP composite sponge turned out to be a promising material for prehospital emergency hemostasis, which provide a model of high-valued application of SSP bioresources.