Reconstruction Of Human Scalp Dermal Papilla With Microencapsulation In Vitro And Study Of The Permeability Of Microcapsules Membrane

ObjectiveTo simplify the isolation of dermal papillas(DPs) from human scalp specimens and realize the large-scope culture of DP cells in vitro. The DP cells were encapsulated with alginate-polylysine-alginate(APA) to reconstruct DP in vitro. The microencapsulated DPs were implanted into the mouse ear wounds in order to convince the induced function of reconstructed DPs. To clarify the feasibility of reconstructed DPs and search a reasonable diameter for reconstructed DPs by comparing the reconstructed DPs (microencapsulated DPs) and fresh isolated DPs in their morphology, function and the permeability of membrane. Methods1. Pretreated hair follicle with collagens I for 2-3 hours, then lOfold DMEM solution was added to the mixed solution . Picked up the DPs by using a pipette gun under the binocular dissecting microscope.2. The DP cells were encapsulated with alginate-polylysine-alginate by using a high-voltage electric field droplet generator. Assessed the reconstructed DPs by comparing the configuration , histological examination, microscopical structure and xenotransplantation the reconstruction DPs in the rat ear wounds. After the xenotransplantation, observed them timely and studied the histomorphology by microscopy at the end of 6 weeks.3. Observed the diffusion way and speed of the fluorenscein-dextran of 10ku,40ku,70ku molecular weight into the microcapsules by confocal laser scanning microscopy. Made a comparison of the fluorenscein intensity of difference diameters of APA microencapsulations inside the microencapsulations. A reasonable diameter of reconstructed DP was thus deduced from the study above, then compared the permeability of fresh DPs and reconstructed DPs of that diameter.Results1. The attachment rate of the DPs reached to 99% . The Dermal papilla cells isolated were pure and without any epithelial contamination. Both operating time and workload were reduced significantly.2. The reconstructed DPs were greatly similar to the fresh isolated DPs in morphology andmicroscopical structure. New shapes of DPs were found from the cultured reconstructed DPs by microscopy. At the end of 6 weeks' following xenotransplantation of microencapsulated DPs, fully developed hair follicles, which were different from the control groups in configuration ,number, size and differentiation , could be easily identified in the skin of implant site by microscopy.3. The fluorenscein was diffused gradually into the microcapsulations with a shape of concentric circularity. An inverse ratio was observed in molecular weight of fluorenscein-dextran and microencapsulation permeability. The fluorenscein intensity inside big (2200.80+183.92) vs. middle (2308.10+159.85) groups were different(P<0.05), and a great difference was found between big(2200.80 +183.92) and small(2989.50± 164.13) microencapsulations(P<0.01). The fluorenscein intensity inside reconstructed DPs(2649.50 + 689.879)whose diameter was 400 u m and fresh DPs (2001.50+167.25) were different (P<0.05).Conclusions1. The improved one step digestive treatment with Improved Collagenase I is a simple and efficient method for isolation and cultivation of DPs from human scalp hair follicles.2. The reconstructed DP retains not only the fresh isolated DP's morphological characteristics but also physiological function.3. The APA microencapsulation ensures the nutrition and metabolite to pass in and out freely, and isolats the immunocompetent substance absolutely. The reasonable diameter of reconstructed DPs was 400 u m.