ZIF-8 nanoparticles combined with fibroin protein co-modified TiO2 nanotube arrays to construct a drug sustained-release platform

Anodized titanium dioxide nanotubes (TNTs) on titanium surface provide a drug delivery platform for local drug therapy at the implantation site. Here, we used TNTs as the drug carrier and modified it with zeolite imidazolium salt skeleton-8 (ZIF-8) combined with silk fibroin (SF) to obtain a new drug loading platform to prolong the drug release time. The morphology, modification effect, drug release in vitro, cell biological activity and osteogenesis of the drug-loaded platform were evaluated. ZIF-8 nanoparticles are mesoporous and filled in nanotubes, and silk fibroin was covered on the surface of nanotubes in the form of thin films. In vitro drug release experiments showed that the silk fibroin membrane combined with biological crosslinking agent genipin (GNP) effectively blocked the diffusion of drugs and prolonged the drug release to 60 days. The study of cell proliferation and osteogenic differentiation showed that the drug-loaded platform was biocompatible and could promote ALP secretion. Therefore, the studies imply that the drug loading platform co-modified by TNTs-based ZIF-8 nanoparticles and silk fibroin can be used as a potential and ideal orthopedic implant.