Influence Of In Vitro Spatial Organization Of Hair Follicle-associated Cells On Hair Follicle Regeneration

Self-transplantation of hair follicles is currently the main treatment for hair loss.This strategy is inapplicable for patients with severe hair loss due to insufficient hair follicles for transplantation.Dermal hair papilla cells(DPC)play an important role in the hair recycling cycle.Our group previously demonstrated that 3D spherical culture of dermal fibroblasts led to DPC-like cells,which offers a new cell sorurce for cell regeneration.A series of signaling pathways are involved in the formation of hairs and many of them are related to epithelial-mesenchymal interactions.It is unknown whether the induction of dermal fibroblasts into DPC-like cells can be affectd by organizing epithelial and mesenchymal cells into different spatial structures.This thesis intends to investigate the effects of in vitro spatial organization of cells on dermal fibroblasts.The main studies are as follows.1)The spatial distributions of epithelial and mesenchymal cells were constructed by electrostatic spray technique to obtain core-shell structured,parallel structured and simple mixture alginate-based cellular microspheres.2)The activity of cells in different cellular microspheres was examined by live-dead staining and CCK-8 assay;Q-PCR and alkaline phosphatase staining were employed to analyze the effect of intercellular spatial distribution on inducing dermal fibroblasts to DPC-like cells at gene and protein levels.3)Dermal fibroblasts and epithelial cells post three days of spherical cultivation in different cellular microspheres were injected subcutaneously into nude mice.The regeneration of hair follicles was determined by means of H&E and other tests after three weeks.This thesis verified that the effects of different spatial distributions of cell populations on inducing dermal fibroblasts to DPC-like cells were differentiated.Dermal fibroblasts showed upregulated marker genes of dermal papilla cells after pretreatment within simple mixture microspheresed and parallel structured microspheres.Qualitative and quantitative ALP staining results and signaling pathway analysis confirmed that co-culture of dermal fibroblasts with epethial cells in parallel-structured microspheres would remarkably benefit the induction of the former cells into DPC-like cells and the resultant dermal cells was beneficial for hair follicle regeneration.