Oyster shell powder reinforced chitosan-poly(vinyl alcohol) freeze-dried composite sponge for on-site hemorrhage control.

A composite hemostatic sponge consisting of chitosan (CS) with oyster shell powder (OSP) has been developed as a potentially sustainable composite material for controlling hemorrhage at the injury site. The system is designed assuming that Ca+ released by OSP will accelerate the effect of chitosan at damage sites, enhancing the overall hemostatic efficacy. The sponge was thoroughly characterized using FTIR, SEM, and EDX analysis. In vitro, blood clotting assays such as clotting time (CT) [188 ± 4 s], prothrombin time (PT) [36 ± 1 s], activated partial thromboplastin time (aPTT) [51 ± 2 s], and plasma recalcification time (PRT) [58 ± 3 s] demonstrated that the inclusion of CaCO3 significantly improved clot formation, with the CS-OSP sponge outperforming control sponges without OSP. RT-PCR analysis of vascular endothelial growth factor A (VEGF-A), platelet-derived growth factor (PDGF), and interleukin growth factor 1 (IGF-1) on fibroblast cell lines evidenced the wound healing-promoting activity of OSP-reinforced CS sponges. This was further supported by in vivo studies using a rabbit femoral artery injury model, where the CaCO3-enhanced sponge achieved superior hemostasis and reduced blood loss more effectively than the control sponges without CaCO3. These findings suggest that the oyster shell-derived CaCO3 enhances the hemostatic activity of chitosan-based sponges, providing a promising candidate for rapid hemorrhage control in clinical settings, particularly in scenarios involving both oozing and pressurized bleeding.