Investigation and development of bilayer scaffolds: ZnONPs-loaded poly (vinyl alcohol) incorporated with Platostoma palustre aqueous extract and sponge collagen derived from fish skin

Abstract

This study introduces the design of two bilayer scaffolds that offer safety and show potential for biomedical applications, especially for wound healing in the skin or oral cavity. Each scaffold is composed of a collagen sponge layer derived from warm-water fish skin (seabass and tilapia) and a PVA layer incorporated with Hsiantsao extract and biosynthesized ZnONPs. Both extracted collagens were identified as type I, with their purity and triple-helical structure confirmed by electrophoresis, FT-IR, UV-Vis, and EDX analyses. TEM characterization revealed that the ZnONPs were small (7.95 ± 1.45 nm) and spherical. The bilayer scaffolds utilize the unique functions of each layer: the denser PVA layer, integrated with nanoparticles, acts as a barrier against dust and bacteria and releases bioactive compounds from the Hsiantsao extract, while the sponge collagen layer supports cell proliferation. Mechanically, the scaffolds showed high flexibility, with a tensile strength of about 4 MPa and an elongation at break of around 300%. They also absorbed fluids rapidly and maintained a slightly acidic pH (6.5–6.8). Additionally, the scaffolds exhibited excellent biocompatibility (cell viability > 115% after 48 h and a hemolytic percentage < 1.5%), strong antioxidant activity (69–70% DPPH and 80% ABTS scavenging), and antimicrobial properties against both Gram-positive and Gram-negative bacteria. These findings suggest that the Hsiantsao/ZnONPs-loaded PVA/Seabass and Hsiantsao/ZnONPs-loaded PVA/Tilapia scaffolds are promising candidates for medical treatments.