Effect of chitin-architected spatiotemporal three-dimensional culture microenvironments on human umbilical cord-derived mesenchymal stem cells

Mesenchymal stem cell(MSC)transplantation has been explored for the clinical treatment of various diseases.However,the current two-dimensional(2D)culture method lacks a natural spatial microenvironment in vitro.This limitation restricts the stable establishment and adaptive maintenance of MSC stemness.Using natural polymers with biocompatibility for constructing stereoscopic MSC microenvironments may have significant application potential.This study used chitin-based nanoscaffolds to establish a novel MSC three-dimensional(3D)culture.We compared 2D and 3D cultured human umbilical cord-derived MSCs(UCMSCs),including dif-ferentiation assays,cell markers,proliferation,and angiogenesis.When UCMSCs are in 3D culture,they can differentiate into bone,cartilage,and fat.In 3D culture condition,cell proliferation is enhanced,accompanied by an elevation in the secretion of paracrine factors,including vascular endothelial growth factor(VEGF),hepa-tocyte growth factor(HGF),Interleukin-6(IL-6),and Interleukin-8(IL-8)by UCMSCs.Additionally,a 3D culture environment promotes angiogenesis and duct formation with HUVECs(Human Umbilical Vein Endothelial Cells),showing greater luminal area,total length,and branching points of tubule formation than a 2D culture.MSCs cultured in a 3D environment exhibit enhanced undifferentiated,as well as higher cell activity,making them a promising candidate for regenerative medicine and therapeutic applications.

Construction of multifunctional hydrogel with metal-polyphenol capsules for infected full-thickness skin wound healing

Damaged skin cannot prevent harmful bacteria from invading tissues,causing infected wounds or even severe tissue damage.In this study,we developed a controlled-release antibacterial composite hydrogel system that can promote wound angiogenesis and inhibit inflammation by sustained releasing Cu-Epigallocatechin-3-gallate(Cu-EGCG)nano-capsules.The prepared SilMA/HAMA/Cu-EGCG hydrogel showed an obvious inhibitory effect on Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus).It could also promote the proliferation and migration of L929 fibroblasts.In vivo full-thickness infected wound healing experiments confirmed the angiogenesis and inflammation regulating effect.Accelerate collagen deposition and wound healing speed were also observed in the SilMA/HAMA/Cu-EGCG hydrogel treated group.The findings of this study show the great potential of this controlled-release antibacterial composite hydrogel in the application of chronic wound healing.