Preliminary study on inhibition of the hair follicle development by siRNA targeting Wnt10b in the cultured rat embryonic skin / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate whether the suppression of Wnt10b by siRNA could prevent the development of hair follicle in the cultured rat embryonic skin.</p><p><b>METHODS</b>siRNA-Wnt10b was synthesized by chemosynthesis method. The dorsal skin of SD rat at embryos were cultured in DMEM in the presence of different percentage of interfering RNA targeting Wnt10b. Wnt10b/beta-catenin expression was analyzed by real-time PCR everyday and by Western blot on the third day. The cultured embryonic skin underwent paraffin embedding, section, HE staining on the third day,in which the number of de novo hair follicle was calculated and statistically analyzed.</p><p><b>RESULTS</b>Wnt10b gene in the cultured embryonic skin could be knocked down with the siRNA-based method. Beta-catenin mRNA was not greatly influenced by the downregulation of Wnt10b mRNA. The number of de novo hair follicle placode in cultured embryonic skin decreased, along with the downregulation of Wnt10b and beta-catenin proteins expression.</p><p><b>CONCLUSIONS</b>The downregulation of Wnt10b mRNA and protein by siRNA reduces the number of de novo hair follicle placode in the cultured rat embryonic skin. Wnt10b may control cytoplasm beta-catenin concentration at the protein level.</p>

Induction of hair follicle regeneration in rat ear by microencapsulated human hair dermal papilla cells / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To induce hair follicle regeneration in rat ear by microencapsulated dermal papillae (DP) cells.</p><p><b>METHODS</b>Intact dermal papillae were obtained from human scalp follicles which were digested with collagenase I. The human hair DP cells were encapsulated with alginate-polylysine-alginate (APA) by a high-voltage electric field droplet generator. The diameters of the DP cell microcapsules were optimized by regulating the voltage, the distance between the needle head and the solution surface and the injection speed. Then DP cell microencapsulations were xenotransplanted into ears of 20 SD rats with a novel method. One rat was killed every week at the postoperative 2-12 weeks and the implantation sites were biopsied for histological observation.</p><p><b>RESULTS</b>The DP cell microencapsulations were found in a group of round, smooth and transparent microcapsules under a phase-contrast microscope. The optimal combination of parameters to obtain 0.4 mm DP cell microcapsules was voltage 7.0 kV, injection speed 55 mm/h, and distance 10 mm. After 4-12 weeks, 18 of 20 DP cell microcapsule implantations had produced high-density hair. Histological observation indicated that both large follicles and sebaceous gland structures were formed in the rat ear within 3-12 weeks.</p><p><b>CONCLUSIONS</b>These findings show that the DP cell microencapsulation maintain the capacity for initiating the follicle regeneration and can be considered as a substitute for fresh isolated dermal papillae.</p>

Induction of hair follicle regeneration in mice ear by microencapsulated human hair dermal papilla cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To induce the hair follicle regeneration in mice ear by microencapsulated dermal papillae cells (DPs) and to investigate the permeability of fluorescein in APA microencapsulation to search the ideal diameter of microencapsulation.</p><p><b>METHODS</b>The DPs were encapsulated with alginate-polylysine-alginate by a high-voltage electric field droplet generator. The microencapsulated dermal papilla cells were xenotransplanted into the mice ears. After 6 week, the histological examination was made by microscopy. The diffusion way and speed of fluorescein into the microencapsulations were observed by confocal laser scanning microscopy. The comparison of fluorescein intensity was made in APA microencapsulations with different diameters.</p><p><b>RESULTS</b>Fully developed hair follicles could be easily identified in the skin of implanted site following xenotransplantation of microencapsulation DPs, which were different from the control groups in configuration, number, size and differentiation degree. The fluorescein was diffused gradually into the microencapsulations with a shape of concentric circularity. The fluorescein intensity inside three groups of APA microencapsulations was: small > middle > big.</p><p><b>CONCLUSIONS</b>The microencapsulated DPs retain the physiological function to induce the follicle regeneration. The APA microencapsulations with 400um diameter could ensure the nutrition and metabolite to pass in and out freely, and isolate the immunocompetent substance absolutely.</p>