Modification Of Hyaluronic Acid And Construction Of Wound Dressing

As the body’s first protective barrier,the skin is easily affected by external forces,leading to trauma.Adverse factors such as massive bleeding,infection,and excessive inflammatory responses in the wound can all lead to delayed skin self-repair.In order to accelerate wound closure,hydrogel wound dressings have maintained a high research interest because of their advantages such as extracellular matrix-like structure,high moisture retention,and good biocompatibility.Nowadays,hydrogel-based wound dressing derivative selfgel powder adhesives have attracted attention in this research field because of their high water absorption properties,rapid self-gelling ability,and high adhesion strength.The first part of this article.Firstly,a small-batch synthesis formula for oxidation of hyaluronic acid HA was explored to prepare OHA with different degrees of hydroformylation.Based on the consideration of blood compatibility and the amount of aldehyde groups,further research on the production process of OHA-2 was carried out.Through the pilot-scale and large-scale synthesis of OHA-2,as well as the residual amount of impurities,the mass production process conditions were fine-tuned to achieve stable production of OHA-2.Secondly,in order to explore the effect of HA purity on the synthesis and properties of OHA,a small-batch synthesis formula for the oxidation of medical grade hyaluronic acid HA-MD was carried out to prepare OHA-MD with different degrees of hydroformylation.It was confirmed that OHA-MD-2 had similar blood compatibility and healing effect as OHA-2.The second part of this article.Taking OHA-2 as the basic skeleton and adding branched polyethyleneimine(PEI)modified heat-sensitive polymer poloxamer 407(F127),a temperature-sensitive shrinkage self-gelling powder adhesive OHFP was prepared.Through rheological,lap-shear,water absorption,hemolysis,and cytotoxicity tests,it is verified that the adhesive has the advantages of gel-sol transition performance,high adhesion performance,high water absorption,good biocompatibility,etc.OHFP-2 rapidly gels by absorbing blood or exudate(Schiff base reaction),utilizes the interaction between aldehyde groups on OHA and tissue amino groups to provide adhesion,and shrinks in response to body temperature to further enhance adhesion strength,achieve rapid hemostasis,and promote wounds closed effect.In conclusion,stable mass production of OHA-2 has been achieved through craft production research,and it has been verified that OHA-2 and OHA-MD-2 have similar biocompatibility and healing-promoting effects.Considering the guaranteed amount of aldehyde groups and economic benefits,a heat-sensitive self-gelling wound dressing was prepared by using OHA-2 to achieve the therapeutic effect of rapid hemostasis and promotion of wound closure.