Study On The Application Of GelMA Hydrogel Loaded With Antimicrobial Peptides And MXene Nanoparticles In The Repair Of Infectious Wounds

Objective: According to the current demand,we plan to design a new hydrogel dressing for wound,which can replace traditional dressing,promote skin healing and have antiinfection ability at the same time.To provide a new therapeutic idea and scheme for the repair of infectious skin defects.Methods: In this study,the photosensitive hydrogel dressing was prepared using MXene nanoparticles loaded with GelMA(methylacrylyl gelatin)and tick-derived antibacterial polypeptide Os.The composite photosensitive hydrogel was characterized by material science and tested in vitro and in vivo.The mechanical properties of composite hydrogels were tested by universal testing machine.The swelling and degradation properties of the composite hydrogel were tested in vitro.The antibacterial properties of hydrogel were tested by absorbance spectrophotometry and live staining of bacteria.The biocompatibility of the composite hydrogels was evaluated by CCK-8 counting,cell staining for life and death,and cell staining for FITC/DAPI.The effect of hydrogel on the rate of wound repair was verified by the calculation of wound healing rate through the preparation of full-layer skin defect model in rats.H&E,Masson,Sirius red staining and other histological analysis were performed on the new skin tissue to test the wound repair effect of hydrogel.The biological toxicity of hydrogel was analyzed by H&E staining on the internal organs of experimental rats.Through a series of experiments,the material characterization,biological properties and in vivo effects of the photosensitive hydrogel dressing were systematically investigated.Results: With the addition of Os and MXene nanoparticles,the surface roughness of the composite hydrogel was significantly increased under scanning electron microscope.Mechanical experiments showed that Os and MXene could improve the compression resistance of hydrogel materials,and the difference of compression modulus of hydrogel among all groups was statistically significant(P< 0.05).The swelling property of the composite hydrogel was also significantly improved,and the swelling rate of hydrogel was significantly different among all groups(P<0.05).The composite antimicrobial peptides and MXene nanoparticles had no significant effect on the degradation performance of hydrogel(P > 0.05).Antibacterial experiments showed that GelMA/Os/MXene nanocomposite hydrogels showed the highest antibacterial effect.In vivo proliferation experiments showed that GelMA/Os/MXene group showed the strongest proliferative properties and fibroblast spread morphology reached the maximum on GelMA/Os/MXene group hydrogel.In vivo experiments in rats showed that GelMA/Os/MXene composite hydrogel could significantly accelerate wound healing,and the healing rate reached the maximum.H&E staining results showed that the epidermal thickness of GelMA/Os/MXene composite hydrogel group was the thinner.MASSON staining and Sirius scarlet staining showed that GelMA/Os/MXene composite hydrogel group had the highest degree of skin maturity.H&E staining of rat organs showed no inflammatory cell infiltration and pathological changes in the experimental group.Conclusion: In this study,MXene nanoparticles loaded with GelMA(methylacrylyl gelatin)and tick-derived antibacterial polypeptide Os were used to prepare photosensitive hydrogel.The new hydrogel significantly improved the mechanical properties of the material,had in vivo degradation ability and swelling characteristics,could provide a moist repair environment for the wound surface,had excellent antibacterial ability,and could promote fibroblast proliferation.It has good biocompatibility,can promote wound healing,can promote collagen deposition,can promote new skin maturation,and has no biological toxicity.It is expected to be an important material for new wound dressing in the future.