Preparation Of Light-assisted Antibacterial Composite Hydrogel And Its Mechanics And Wound Healing Function

Hydrogels have been extensively researched in the field of wound dressing because their heavily-hydrated 3D porous structures allow them to mimic human tissue microenvironment and provide a moist environment on the wound.However,conventional hydrogels do not possess antibacterial property.Clinical treatment for infections mainly relies on systemic antibiotics,while the excessive use of antibiotics has led to the spreading of multidrug-resistant bacteria.Moreover,hydrogels usually exhibit relatively poor mechanical performance,which limit their clinical application.In response to these problems,β-graphene oxide(β-GO)with good photothermal property under 808 nm near-infrared light,rose bengal(RB)with good photocatalytic property under 550 nm visible light and polyvinyl alcohol(PVA)hydrogel were hybridized to prepare light-assisted antibacterial composite hydrogel.At the same time,the introduction of the β-GO network structure significantly enhanced the mechanical property of the composite hydrogel.The main research contents of this subject are as follows:(1)Firstly,the biological crosslinking agent β-cyclodextrin aldehyde(β-CD-DA)was used to crosslink graphene oxide(GO)to form β-GO,and RB was grafted onto chitosan by chemical bond.Then β-GO nanoparticles,chitosan particles grafted with RB and PVA were synthesized through freeze-thaw cycles to prepare β-GO/RB/PVA composite hydrogel.X-ray photoelectron spectroscopy(XPS),field emission transmission electron microscopy(TEM),field emission scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)were used to characterize the microstructure of synthetic nanoparticles and hydrogels.The experimental results confirm that the β-GO/RB/PVA composite hydrogel was successfully prepared.The mechanical propertiy of the hydrogel was evaluated through tensile and compression experiments.The results show that the mechanical property ofβ-GO/RB/PVA composite hydrogel was significantly enhanced.(2)The antibacterial property of the composite hydrogel in vitro was evaluated by spread plate experiment,fluorescence staining experiment and SEM morphology observation.The experimental results show that the β-GO/RB/PVA composite hydrogel could generate a large amount of reactive oxygen under 550 nm visible light irradiation and generate a large amount of heat under 808 nm near-infrared light irradiation.Under dual light(550 nm + 808 nm)irradiation,the synergistic effect of photodynamic and photothermal could quickly kill bacteria within 10 min.The vivo antibacterial experiments also show that the composite hydrogel had excellent antibacterial property in vivo under dual light(550 nm + 808 nm)irradiation.(3)The vitro biocompatibility of the hydrogel was evaluated by fluorescence staining experiment and MTT experiment,the results show the composite hydrogel had good biocompatibility.Through the establishment of an infected wound model,the wound healing function and the vivo biocompatibility of the β-GO/RB/PVA hydrogel were evaluated.It was found that the composite hydrogel could effectively promote wound healing by controlling infection,and exhibited good in vivo compatibility.