Topological Modulation And Biofunctionalization Of Nanofibers Scaffolds In Promoting Wound Healing In Burned Rats

Objective:Chronic non-healing wounds caused by serious wound defect are a serious complication that can easily threaten patients’ lives due to damaged skin microvasculature and the accumulation and long duration of action of inflammatory cells.Therefore,novel wound dressings with prominent wound repair are urgently needed.Composite structured nanofiber scaffolds can be prepared by electrospinning technology and have been widely used in the field of regenerative repair due to their superior bionic properties and biocompatibility.Methods:1.Multi-layered nanofiber scaffolds were prepared using electrospinning,nanofibers yarn and electrospraying techniques.Polycaprolactone(PCL)coated gradient epidermal growth factor(EGF)radially aligned nanofiber scaffolds as the upper layer;Gel with methacryloyylated chitosan(CSMA)random nanofiber scaffolds as the middle layer;gelatin with nanofiber yarn PCL coated uniform decellularized dermal matrix(ADM)mesh topography scaffold as the lower layer.2.To investigate the effect of topological signals provided by radially aligned scaffolds versus biochemical signals provided by active factors on epidermal repair,this study was conducted to evaluate the effect of radially aligned nanofiber scaffolds coated with gradient EGF on epidermal cell migration and proliferation by CCK-8 and cell migration assays.3.To investigate the antibacterial properties possessed by wound dressings,this study examined the antibacterial properties of CSMA-incorporated mid-layer scaffolds against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by agar plate diffusion assay and cytotoxicity assay.4.To investigate the role of mesh topology and ADM biochemical signaling on the regulation of adipose stem cells(ADSC),this study was conducted to evaluate the effect of regulated adipose stem cell paracrine secretion on fibroblast migration.Results:1.Three multi-layered scaffolds with bionic properties for different skin level repair respectively,radially aligned nanofiber scaffolds successfully coated with gradient EGF;gelatin nanofiber scaffolds successfully loaded by photo-crosslinking CSMA;nanofiber yarn technology and photo-welding technology successfully prepared mesh scaffolds and intercalated gelatin short fiber coated with ADM active protein.2.The radially aligned nanofiber scaffolds with coating gradient had significantly higher proliferation and migration rate of epidermal cells than the control group and radially aligned nanofiber scaffolds.3.Antimicrobial assay(antimicrobial circle size): Gel/CSMA > Gel.cell proliferation of gelatin nanofiber scaffolds loaded with CSMA was not significantly different from other groups(P > 0.05).4.Simulated the real time state of wound healing,the migration of fibroblasts by adipose stem cell paracrine regulated by the mesh topography scaffold coated with ADM was faster than other groups.Conclusion:This study demonstrated the designed triple scaffolds with different topologies and biofunctionalized the upper and lower layers.The different properties performed by the three-layer scaffold in wound healing were evaluated.The upper layer scaffold has significant effects on epidermal cell migration and proliferation;the middle layer scaffold has antibacterial properties;and the lower layer scaffold loaded with ADSC regulates fibroblast migration.In further refining the topological structure and biofunctionalization interactions,a foundation is laid for guiding the auxiliary secretory signaling network to develop scaffold materials to promote tissue regeneration and repair.