Study On The Properties Of Proanthocyanidin Crosslinked Chitosan/Gelatin Sponge For Wound Hemostasis And Healing

Uncontrolled bleeding is the main cause of death for injured people during wars,traffic accidents,natural disasters and surgical procedures.The natural polymer hemostatic materials commonly available on the market have the advantages of high biocompatibility and degradability,but the hemostatic effect is general,and the rapid hemostasis for patients with hemorrhage is very poor.In addition,the wound healing process after hemostasis is generally long,and medical materials with anti-inflammatory and antibacterial functions have been shown great healing-promoting effects.Therefore,there is one need to develop new natural polymer hemostatic materials that can simultaneously achieve both rapid hemostatic effect for hemorrhage and wound healing-promoting medical functions.In the first part of this thesis,the preparation process and hemostatic effect of proanthocyanidin cross-linked chitosan/gelatin sponge(PCGS)was investigated in a two-step process.In the first step,different ratios of chitosan/gelatin composite sponge(CGS)were prepared by using the selffoaming property of gelatin under high-speed stirring;the optimal ratio of chitosan/gelatin composite sponge CGS7 was screened by liquid absorption performance test and blood coagulation index test.In the second step,the Schiff base cross-linking reaction of CGS7 by procyanidin(PC)immersion was performed to prepare the CGS7 with improved mechanical strength.In vitro tests demonstrated that PCGS7 has high hemocompatibility and in vitro procoagulant properties(low in vitro coagulation index),and further demonstrated by femoral artery hemostasis experiments that PCGS7 can effectively control large vessel bleeding with better performance than commercially available gelatin sponge.Based on the first part,the second part investigated the antibacterial and antioxidant properties and wound healing-promoting effects of PCGS7.Firstly,the sponge was tested for its minimum antibacterial concentration by co-culture with bacterial solution,which proved that the sponge has better antibacterial properties;the presence of free radicals can lead to the aggravation of wound inflammation,so we further tested the scavenging rate of superoxide radicals and DPPH radicals by the sponge which proved that PCGS7 has stronger free radical scavenging ability.Finally,it was verified by the healing experiment after the infection of tooth extraction sockets in rats,which showed that PCGS7 has the anti-infection property and can effectively inhibit the inflammatory secretion of wounds and accelerate the healing of infected wounds.