Nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/chitosan scaffolds for skin regeneration

The purpose of this study was to evaluate hybrid poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/chitosan nanofibrous mats as scaffolds for skin engineering. In vitro studies were carried out to test the potential of the scaffolds for fibroblasts adhesion, viability, and proliferation (L929 cell line). The in vivo performance was also studied in a full-thickness wound healing model. PHBV/chitosan 4:1 w/w exhibited a higher in vitro biocompatibility and a better ability for cell adhesion and growth, compared to PHBV/chitosan 2:3 w/w. The in vivo assay also revealed the better performance of this scaffold, improving the wound healing process in rats

Effect of a low-molecular-weight compatibilizer on the immiscible blends of cellulose acetate propionate and poly(butylene terephthalate)

[[abstract]]Blends of poly(butylene terephthalate) (PBT) and cellulose acetate propionate (CAP) were found to be immiscible. In order to improve the interfacial strength and miscibility of the PBT/CAP blends, a low-molecular-weight poly(ethylene glycol) (PEG) was thus pre-mixed with the CAP to form the P-CAP mixture. It was then blended with the PBT up to 15 wt% using a twin-screw extruder to prepare the PBT/P-CAP blends, and subsequently processed into the films and fibers by compression-molding and melt-spinning, respectively. The thermal and dynamic mechanical analyses suggested that the PBT and CAP became partially miscible and the interfacial strength was thus improved in the PBT/P-CAP blends, owing to the addition of PEG. The PEG was not only miscible with the CAP but also with the PBT, and it served as a plasticizer as well as a compatibilizer. From the observation of the fractured surface of the PBT/P-CAP films, the PBT component was present as dispersed particles in the P-CAP matrix with size ranging from 1.4 to 3.0 μm; yet it became nanofiber in the spun fibers. Successful fibers of the PBT/P-CAP blends with an average diameter of 20 μm could be spun, where the tensile strength and elongation at break were in the range of 0.6−0.7 g/denier and 12−16%, respectively. Finally, the ultra-fine PBT nanofibers with diameters in the range of 50−70 nm were observed after removing the P-CAP matrix with acetone from the fibers, owing to the formation of PBT nanofibers during spinning and orientation processes. This method thus could successfully produce nano-scale PBT fibers with fineness comparable with the nanofibers developed via electrospinning technology.[[notice]]補正完