Fabrication of a Biodegradable Multi-layered Polyvinyl Alcohol Stent.

This study aims to develop biodegradable vascular stents that prevent permanent damage caused by rejection of the immune system of the human body. Polyvinyl alcohol (PVA) yarns are twisted to enhance their strength. The twisted yarns are braided and then coated with chitosan (CS). The CS-coated PVA vascular stents are chemically crosslinked with genipin (GP) to improve their flexibility and biodegradability. Their morphological characteristics are also observed using a stereoscopic microscope, and their properties are evaluated through scanning electron microscopy, Fourier transform infrared, bending test, biodegradability test, drug release measurement, and MTT assay. Results reveal that wet PVA-CS-GP vascular stents coated with multiple CS layers can maintain a tubular structure when they are bent. After crosslinking is performed, the compressive strength of the PVA-CS-GP stents is 17.04 times higher than that of pure PVA. The weight loss rate of the PVA-CS-GP vascular stents as <3 % after 30 days. The PVA-CS-GP vascular stents composed of 0.10 % heparin sodium show a good drug release effect. Biological activity test indicates that these stents exhibit good proliferation, and our structural model verifies that they are good vascular stents. [ABSTRACT FROM AUTHOR]