Wound Healing Activity of a Skin Substitute from Residues of Culinary-Medicinal Winter Mushroom Flammulina velutipes (Agaricomycetes) Cultivation.

A skin substitute TG05 obtained from residues of the culinary-medicinal mushroom Flammulina velutipes cultivation process was developed in this study for the first time. Pre-column derivatization high-performance liquid chromatography fingerprints analysis revealed that TG05 was composed of water-insoluble fibers containing xylose (57%), glucose (19.5%), and arabinose (16.3%) as major monomers. Porous and opaque structure of TG05 was demonstrated by scanning electron microscopy. Animal experiments conducted on mice and rats indicated that TG05 notably accelerated the wound-healing process. In addition, TG05 induced proliferation and migration of human keratinocytes time- and dose-dependently. Taken together, the skin substitute TG05 with new structure promotes wound healing in vitro and in vivo. This study provided a novel method to produce functional biomaterial from abundant and low-cost agricultural residues generated during edible mushroom cultivation.

Exendin-4 relieves the inhibitory effects of high glucose on the proliferation and osteoblastic differentiation of periodontal ligament stem cells.

BACKGROUND: With the impaired regenerative potential in patients with diabetes mellitus (DM), Periodontal ligament stem cells (PDLSCs) are regarded as an attractive source of stem cells for periodontal cytotherapy. Recent studies have shown that Exendin-4 (Ex-4) exerts cell-protective effects and bone remodeling ability on many types of cells. The aim of this study was to investigate whether Ex-4 alleviates the inhibition of high glucose on the proliferation and osteogenic differentiation of PDLSCs. METHODS: PDLSCs were incubated in medium supplemented with 5.5 mM d-glucose (NG), 30 mM d-glucose (HG), NG plus Ex-4, and HG plus different concentration (1, 10, 20, 100 nM) of Ex-4 respectively. Cell proliferation was detected by CCK-8 assay and cell cycle analysis. Osteogenesis was assessed by Alizarin Red S staining and evaluation of the mRNA expression of Runx2, ALP and Osx at day 7, 14 and 21. Intracellular level of reactive oxygen species (ROS) was detected using 5-(and-6)-chloromethyl-2',7'-dichlorodihydro-fluorescein diacetate (CMH2DCF-DA). RESULTS: The proliferation ability, mineralized nodules forming capacity and the mRNA expression of Runx2, ALP and Osx of PDLSCs in HG group were decreased, the ROS level was increased compared to NG group. With the treatment of Ex-4, the HG-inhibited proliferation ability and osteogenic differentiation ability of PDLSCs were significantly reversed, the HG-increased ROS level could be down-regulated. Moreover, Ex-4 enhanced the osteogenic differentiation of normal PDLSCs. CONCLUSIONS: Ex-4 alleviates the inhibitory effect of HG on the proliferation and osteoblastic differentiation of PDLSCs, and has a significant enhance in the osteoblastic differentiation of normal PDLSCs, giving new insights into the possible therapeutic method of diabetic periodontitis.