No abstract

There have been numerous investigations regarding various types of dressings and artificial dermis of solid form, yet limited research and development on paste types, such as hydrogels with dermal powder, have ensued. In this study, we compared the in vivo wound healing effects of gelatin paste containing dermal powder to a collagen type I/chondroitin 6-sulfate (coll/chondroitin) sponge and gelatin alone, after 48 days post grafting, in a skin wound rat model. In the dermis powder/gelatin paste-treated group, wound area contraction was minimized 50%, while in the gelatin and coll/chondroitin sponge groups, the initial area contracted 83-85% and 79-85%, respectively. Histological analysis revealed the wounds treated with dermal powder/gelatin were associated with many fibroblasts, which infiltrated the wound bed, as well as thick collagen bundles that were arranged in dendritic arrays, resembling normal skin. Furthermore, in contrast to the gelatin- and coll/chondroitin sponge-treated groups, the powder/gelatin paste-treated wounds exhibited an abundance of elastic fibers (Victoria blue staining) and extensive formation of blood vessels around the dermis (CD31 staining). Therefore, the dermis powder/gelatin paste not only renders convenience to users but also has prominent wound-healing effects on full-thickness wounds.

No abstract

Alopecia is not life threatening, but patients who undergo alopecia often experience severe mental stress. In addition, the number of individuals afflicted by alopecia has been increasing steadily. The most effective treatment of alopecia developed to date is auto hair transplantation. To overcome the limitations associated with current therapies for the treatment of alopecia, many researchers have attempted to revive hair follicles by áå=îáíêç culture of hair follicle cells and subsequent implantation in the treatment area. Previously, we demonstrated that umbilical cord-derived mesenchymal stem cells (UC-MSCs) could be isolated and expanded successfully from the Wharton's Jelly. Cultureexpanded UC-MSCs formed aggregates similar to native dermal papilla (DP) in special media (DPFM) and reconstructed dermal papilla like tissues (DPLTs) could induce new hair follicles. The purpose of the present study was to optimize the reconstruction of DPLTs. As in the case of MSCs, when compared to differentiated cells, DPLTs require an additional step to induce differentiation into dermal papilla cells. However, it is necessary to use hepatocyte growth factor (HGF) in the differentiation step, which is relatively expensive. To reduce the expenses associated with cell therapy using MSCs, it is necessary to optimize this differentiation step. To accomplish this, we evaluated the effects of cell inoculation density and growth factors during differentiation. © KSBB hÉóïçêÇëW=ãÉëÉåÅÜóã~ä=ëíÉã=ÅÉääI=Ü~áê=ÑçääáÅäÉI=ÇÉêã~ä=é~éáää~I=ÅÉää=íÜÉê~éóI=ìãÄáäáÅ~ä=ÅçêÇ= = = = =

Animals have typically been used in efficacy tests, but there are a number of dissimilarities between humans and animals. To overcome the problems associated with animal testing, a model which is reproduced in vitro with longterm culture with cell growth with in vivo activity must be developed. We made a gel-type dermal equivalent (DE) that contained dermal papilla cells (DPCs) or dermal sheath cells (DSCs) isolated from human hair bulbs in order to mimic human scalp tissue. Hair follicles were organ-cultured on DE containing DPCs or DSCs. The DE used for organ culture was a reconstructed 3-dimensional contraction of collagen gel, and the cell density of the DE did not affect the increase in hair length. We tested the effects of cell types in DE on increases in hair length, and the results showed a large increase in hair length and long-term viability in the air-liquid interface culture on DE containing DSCs. We compared the submerged culture with the hair air-liquid interface culture on DE using immunohistochemical staining, and found that the hair follicles that were air-liquid interface cultured on DE maintained the growth phase (anagen) for a longer period of time than the hair follicles that were submerged. Since the hair follicles were cultured under an air-liquid interface condition, the increase in hair length was a reflection of the epithelial cell growth that resulted from the improved oxygen supply and paracrine factors secreted from hair origin cells.