Preparation Of Antibacterial Hydrogel And Coating Based On Tannic Acid And Its Performance Research

Various medical materials such as wound dressings and implantable medical devices have been widely used and played a vital role in modern medical care.However,the surface of medical materials creates an ideal environment for the adhesion of bacteria and the establishment of biofilm.Once the bacteria adhere to the materials and establish the biofilm successfully,the bacteria will destroy the function of the device,resist the host immune system and most antibiotics,resulting in bacterial infection and even threaten life.Therefore,there is an urgent need to develop antibacterial materials that can effectively prevent bacterial adhesion and biofilm formation.Alos,the materials should have good mechanical properties and biocompatibility.In order to prevent bacterial infections on the surface of diabetic foot wounds and implantable medical devices,this article designed two antibacterial materials based on natural plant polyphenol tannic acid,and explored the antibacterial mechanism of the materials as well as their application prospects as medical materials.First,the diabetic foot wounds are often subjected to external forces,the healing speed is slow and the tissue repair is difficult.So,natural plant polyphenol tannin acid,zwitterionic monomer SBMA,and the chemical cross-linking agent polyethylene glycol diacrylate were used by thermal initiation to form the hydrogel.The hydrogel has excellent compression properties,with compressive stress up to19.76MPa.The hydrogel can withstand more than 3,500 compression cycles,and can relieve plantar pressure effectively.The hydrogel can stick to pigskin and glass surface,and the adhesive strength is 20.22 k Pa and 84.00 k Pa,respectively.The free radical scavenging activity of tannic acid makes it has good antioxidant properties.Also,the composite hydrogel has excellent antibacterial property against Staphylococcus aureus to avoid the risk of antibiotic resistance.Experiments in mice have proved that it has the effect of promoting wound healing.The hydrogel is promising for diabetic foot wound repair.Furthermore,to solve the problem of bacterial infections on the surface of implantable medical devices,tannic acid and copper sulfate with inherent antibacterial properties were used to modify the surface of polydimethylsiloxane(PDMS)through a simple one-step assembly method.The antibacterial coatings with tannic acid,tannic acid coordinated with copper ions are prepared respectively.The addition of tannic acid and metal ions reduce the contact angle of the material to39.1°and improve the hydrophilicity.The maximum copper ion content in the coating is 2.33μg/cm~2.The high antibacterial agent content makes the coating have excellent anti-Staphylococcus aureus biofilm and antibacterial activity,the modified material shows low cytotoxicity with a cell viability of 97.65%.The material is expected to be used as an antibacterial coating on the surface of implantable medical devices.