Preparation And Properties Of Injectable Hydrogels With Antibacterial Function For 3D Printing

At present,biomaterials have good application prospects in various fields,and hydrogels are favored by many researchers as polymer materials.Most of the wound dressing products currently on sale are not suitable for specific conditions or to provide a specific dose of medication as requested by the patient.3D-printed drug delivery systems have the potential to provide customized and innovative solutions in this area.3Dprinting can be rapidly produced and designed by digitally controlled layer by layer deposition with computer-aided design（CAD）.The ideal wound dressing should provide a moist environment with antibacterial properties.To solve the above problems,this paper introduced metal ion Al³⁺with hyaluronic acid（HA）and L-glutamic acid（L-GA）as the first layer of network monomers,and formed the first layer of network through ion cross-linking;acrylamide（AM）was used as the second layer of network monomer,which was polymerized to form polyacrylamide by adding initiator（APS）and cross-linking agent（MBA）.The injectable and printable double network hydrogels were prepared by adjusting the ratio of each formula.The specific research contents are as follows:（1）By adjusting the ratio of each raw material,the double-network hydrogel was prepared,named HPA/PAM-x DN hydrogel,and the influence on the material was studied by adding different ion concentrations.The internal structure and functional groups of hydrogel were analyzed by FT-IR,XPS and XRD.The experimental results show that the hydrogel has good tensile properties and can be used as dressing.（2）After analyzing the internal structure and basic properties of HPA/PAM-x DN hydrogel,the equilibrium moisture,swelling degree and environmental sensitivity of HPA/PAM-x DN hydrogel were tested and analyzed,and the swelling kinetics was analyzed.Experimental results showed that the drying rate and swelling degree of the materials changed with the addition of Al³⁺concentration.At the same time,the hydrogel has environmental sensitivity namely p H sensitivity.Taken as a whole,the hydrogel can provide a moist environment and with water retention,satisfying the environment as a dressing.（3）Ciprofloxacin（CIP）was used as a simulated drug to test the drug load of hydrogel;in addition,the bacteriostatic properties of hydrogels soaked in pure essential oil were tested and analyzed,and the bacteriostatic cycles were observed and compared.It was proved that HPA/PAM-x DN hydrogel had sustained drug release behavior and then simulated its sustained release kinetics.With the increase of Al³⁺concentration,the bacteriostatic circle of hydrogel increased,indicating that the bacteriostatic effect was enhanced;at the same time,compared with the filter paper soaked in essential oil,hydrogels have a larger bacteriostatic circle,which indicates that hydrogels themselves have certain bacteriostatic properties.