Fabrication Of Thermal-responsive Hydrogels And Study On Antibacterial Repair Of Surface Wounds

Bacterial infections are the main factor threatening human health.At present,antibiotics are mainly used to eliminate bacteria in clinic.However,many drug-resistant super bacteria have emerged with the large-scale use of antibiotics.Humans are facing a situation where there is no cure.Since the 21st century,nanotechnology is more and more widely used in medicine with the rise of nanotechnology.Among them,silver nanoparticles can produce high-efficiency antibacterial activity due to their large specific surface area,which can be used against drug-resistant bacteria.Antibacterial agents usually need to combine a good carrier to produce good therapeutic effect.The hydrogel has attracted the attention of scientists due to its good biocompatibility.The unique three-dimensional network structure of hydrogel has strong water absorption and moisture retention ability,which can provide a good environment for wound healing.Hydrogel has more advantages than traditional medical dressing.However,there are still many limitations in the application of hydrogels.The ideal method of drug delivery is to release drugs,which meet the physiological needs of patients at the right time and at the exact location.Most hydrogels do not control drug release,so intelligent hydrogels emerge as the times require.It can reduce the harm of unnecessary drug release to the body.In this work,sodium alginate hydrogel with photothermal conversion function has been developed,which can effectively kill bacteria and promote wound healing under the irradiation of near-infrared light.The specific content is as follows:AA-[Zn（OH）₄]^2-amorphous nanoparticles were synthesized by existing methods in the laboratory.ZnO/CaCO₃/Ag composite nanoparticles were successfully prepared by hydrothermal method.The materials were characterized by scanning electron microscopy（SEM）transmission electron microscopy（TEM）X-ray diffraction（XRD）and other tests,and the phase of the materials was determined.Furthermore,composite nanoparticles with different silver contents were cultured with E.coli and S.aureus,and then screen out the composite nanoparticles with the strongest antibacterial performance for the following research.Based on ZnO/CaCO₃/Ag composite nanoparticles,An easily prepared alginate saline gel for wound infection was prepared and studied the effect of loading of composite nanoparticles on the mechanical properties of hydrogels.Then,Polydopamine nanoparticles were loaded into hydrogels to make the hydrogel transform into heat near the infrared light,so that the temperature of the hydrogel system will continuously increase,and then promote the release of silver ions.At the same time,the increase of temperature will lead to the destruction of bacterial cell membrane.Therefore,the combination of hydrogel and laser will produce more significant antibacterial effect.Hydrogels can treat wound infections and promote wound healing.Through the mouse wound infection model,showing the potential of anti-infective drugs.