Injectable Nano Whitlockite Incorporated Chitosan Hydrogel for Effective Hemostasis

Uncontrolled bleeding can lead to many complications that might cause multiple organ failures and even death. Of all the hemostatic agents used, chitosan has been reported to show better hemostatic potential. It acts through one mechanism involved in hemostasis that is plug formation by adhering to the injured site. Hence our focus is to enhance the hemostatic potential of chitosan (Ch) hydrogel by incorporating nano whitlockite (nWH: Ca₁₈Mg₂(HPO₄)₂(PO₄)₁₂) that would release Ca²⁺, Mg²⁺, and PO₄^3- ions that would simultaneously initiate the coagulation cascade. Ch-nWH composite hydrogel can act simultaneously on different mechanisms involved in hemostasis and bring about rapid bleeding control. The nWH particles were synthesized using precipitation technique and were characterized. Particle size of nWH was found to be 75 ± 5 nm. Composite hydrogel was characterized using FTIR and XRD to confirm the presence of different constituents of the hydrogel. Rheological studies showed the shear-thinning property and increased elastic modulus of the composite hydrogel compared to Ch hydrogel. 2%Ch-4%nWH hydrogel was observed to be cytocompatible with Human Umbilical Vein Endothelial Cells (HUVEC). In the in vitro blood clotting analysis using citrated human whole blood, 2%Ch-4%nWH hydrogel showed rapid blood clot formation compared to control 2%Ch hydrogel. Further in vivo experiments performed on liver and femoral artery injuries created on Sprague-Dawley (S.D) rat model reveals that 2%Ch-4%nWH hydrogel promoted rapid bleeding control and less volume of blood loss compared to Ch hydrogel. These in vitro and in vivo results showed that incorporation of nWH has enhanced the hemostatic potential of Ch hydrogel. Therefore, the synthesized 2%Ch-4%nWH hydrogel may be a promising system that could bring about rapid hemostasis during life threatening bleeding.