Pilot Study On Approaches To Reconstruct Dermal Papilla And Its Biological Properties

Objectives: Dermal papilla cells(DPC) isolated from the human scalp samples are passaged to the second passage. Suitable scaffold, including cytodex-3 or cultipher-G,is selected to culture dermal papilla cells. Growth pattern and ability of proliferation in different culture conditions is compared. This paper's focus is mainly on exploring a new bioengineering approach for artificial reconstruction of dermal papilla and assess the capacity of hair follicle(HF) induction by the reconstructed dermal papilla.Methods: Several kinds of cells was isolated and cultured, including dermal papilla cells, fibroblast and epithelial keratinocyte(KC) derived from foreskin via enzyme digestion. Foreskin epithelial stem cell was cultured through the adhesion of typeâ…£collagen. Compared with microencapsules, two microcarriers including cytodex-3 and cultipher-G were applied to culture dermal papilla cells. Growth curves and double-increase time of dermal papilla cells were compared in different culture patterns. These cells were stained immunohistochemically or by toluidine blue to identify dermal papilla cell. Dermal papilla cells, microcarrier-DPCs system was mixed with epithelial stem cell from foreskin,which was added in composite chitosan gel established by our own labratory to study the effect of these systems to the differentiation of epithelial stem cell. These systems were implanted into Balb/c nude mouset. It was observed regularly that the general of the test nude mouse. After 4 weeks, histological slices and immunonohistochemitry stain was applied to assay the formation of hair follicle in vivo and in vitro.Results: There are similarities in the growth periods of dermal papilla cells by traditional monolayer culture and microcarriers culture, but digestion time and double-increase time lags. Dermal papilla cells cultured on cytodex-3 or cultishpher-G reached the maximal cell after 12 days. Cells covered the surface of microcarriers and aggregated as a bulb between microcarriers. Dermal-papilla cell-Microcarriers system was found no formation of hair follicle-like structure in the composite chitosan artificial skin created by our lab after 1 month. But when these systems with epithelial stem cell were implanted into the dermal layer or extroperitoneal layer of Balb/c nude mouse skin, follicle-like structures were observed on the 4th week and on the 8th week. Red keratose was found in the center of sample slices by Haematoylin Eosin stain. Immunohistochemistry: positive to cytokeratin 14 antibody, which indicated the base layer cell of epidermis in the skin, the same as that in hair follicle.Conclusions: 1.Dermal papilla is crucial for normal differentiation of hair follicle and interacts with epithelial stem cells, resulting in the formation of hair follicle. 2.Cytodex-3 or cultishpher-G microcarriers loaded dermal papilla cell can imitate the function of hair-follicle induction by dermal papilla. 3.epithelial stem cells from foreskin have the potency to differentiate hair follicle.