Coaxial Structured Drug Loaded Dressing Combined With Induced Stem Cell Differentiation For Enhanced Wound Healing

At present,the clinical strategies for treating chronic wounds are limited,especially when it comes to pain relief and rapid wound healing.Therefore,there is an urgent need to develop alternative treatment methods.In recent years,how electrospun nanofiber scaffolds promote wound healing,and how to use electrospinning technology to prepare multi-dimensional,porous and multi-functional nanofiber scaffolds have greatly promoted the development of wound healing dressings.The technology of electrospun nanofiber scaffolds with multi-functional nanomaterials has greatly promoted the development of wound healing dressings.Therefore,the combination of controllable drug-loaded dressings with the induced stem cell differentiation and the interaction between nanoparticles and polymers have aroused great interest.In this study,a directional core-shell drug-loaded magnetocaloric response PCL/Gelatin-Antibiotics/Fe₃O₄multifunctional dressing was developed.Due to the magnetothermal heating effect of magnetic nanoparticles and the contraction of elastic electrospun fibers,the fibers release antibiotics as needed to prevent drug-resistant infection.Ⅳ collagenase catalyzes the degradation of gelatin by achieving an optimum reaction temperature,the purpose of which is also to reduce the viscosity of liquid gelatin and promote the release of drugs.With the sacrifice of gelatin,the directional structure of scaffold and the internal steric hindrance promoted stem cell differentiation and wound healing.The expression of Vimentin,VEGF,b FGF,TGF-β,and THY1was confirmed by fluorescence immunostaining and RT-PCR.Western blot was used to detect expression of Vimentin,collagen,CD34,and CD31 in the（5/5,v/v）PCL/gelatin scaffold incubated with mouse wound.Therefore,the functional fibers can significantly accelerate the healing process.Mineralization of hydroxyapatite induced by acidic metal oxides has attracted substantial research interest in the research and development of orthopedic substitutes.In this study,PCL/Ta₂O₅nanocomposites were synthesized by electrospinning the mixture of nano-tantalum oxide（Ta₂O₅）and polycaprolactone（PCL）.The scaffold simulates the mineralization process of hydroxyapatite in simulated body fluid.However,in the process of mineralization,there is a chemical reaction between hydrophobic scaffolds and acid oxides,which is believed to have a significant impact on the biological effects of the scaffolds.The results of SEM,EDS,XRD,Mapping,FTIR,GPC,¹³CNMR,and ~1HNMR explain the principle of hydroxyapatite mineralization induced by Ta₂O₅and the reason why the composite scaffold is blurred,that is,the carbonyl carbon of PCL attacked by the surface hydroxyl groups of Ta₂O₅to catalyze its ring-opening polymerization to synthesize PCL/Ta₂O₅nanocomposites in one step.In order to accurately explore the effect of this reaction on the metabolism of biological macromolecules in the future,we provide a detailed route of AgNPs-DMSA@TAT probe synthesis.The results provide a reference for the sedimentation of hydroxyapatite induced by acid oxides and its effect on traditional electrospun fiber scaffolds.Finally,This paper also summarizes the four stages of wound healing,and then discusses the development of electrospinning technology,the contents of electrospinning equipment and the factors affecting the electrospinning process.Finally,we introduce the possible mechanism of electrospun nanofibers in promoting wound healing,the classification of electrospun polymers,the cell penetration of fiber scaffolds,antibacterial fiber scaffolds,and the future multi-functional scaffolds.Although nanofiber scaffolds have made great progress as a multi-functional biomaterial,it is still a major challenge to commercialize them to fully meet the needs of patients.