A nanofiber hydrogel derived entirely from ocean biomass for wound healing.

Crustaceans and fish scales in the marine food industry are basically thrown away as waste. This not only wastes resources but also causes environmental pollution. While reducing pollution and waste, biological activity and storage of materials are urgent issues to be solved. In this study, by first preparing dry fibers and then making hydrogels, we prepared a fish scale/sodium alginate/chitosan nanofiber hydrogel (FS-P) by cross-linking the nanofibers in situ. From fish and other organisms, fish gelatin (FG), collagen and CaCO3 were extracted. Fish scale (FS)/sodium alginate/chitosan nanofibers were cross-linked with copper sulfide nanoparticles prepared by a one-step green method to obtain FS-P nanofiber hydrogels under mild conditions without catalyst and additional procedures. These fiber hydrogels not only have good tissue adhesion and tensile properties, but also have the antibacterial effect of natural antibacterial and CuS photothermal synergism, which can achieve 51.32% and 49.96% of the antibacterial effect against Staphylococcus aureus and Escherichia coli respectively, avoiding the generation of superbacteria. The nanofiber hydrogels have 87.56% voidage and 52.68% degradability after 14 days. The combined strategy of using marine bio-based fibers to prepare gels promoted angiogenesis and tissue repair.

[Studies on the chemical comstituents of Pithecellobium clypearia].

OBJECTIVE: To study the chemical constituents of Pithecellobium clypearia. METHODS: The compounds were isolated from Pithecellobium clypearia with column chromatography. Their structures were characterized on the basis of their physical and chemical preperties, as well as chromatographic and spectroscopic evidences. RESULTS: A pair of isomeric flavans consisting of 7, 3'-O-di-gallyoltricetiflavan (I) and 7,4'-O-di-gallyoltricetiflavan (II), along with a catechin compound (-)-epigallocatechin-7-O-gallate (III) were isolated from the leaves and twigs of Pithecellobium clypearia. CONCLUSION: Compound I is a new flavan. Compound III is isolated from Pithecellobium genus for the first time, and its 13C-NMR data is firstly given in the present study.