Peptide GL13K releasing hydrogel functionalized micro/nanostructured titanium enhances its osteogenic and antibacterial activity

Bacterial infection and the subsequent lack of osseointegration are two of the main problems encountered during the early stage of implantation. To resolve these issues, in this study, the micro/nanostructure on titanium surface was fabricated by dual-acid treatment and anodic oxidation, and then GelMA hydrogel loaded with GL13K was coated onto the micro/nanostructured titanium. The surface properties of different titanium substrates were characterized by scanning electron microscopy, atomic force microscope, water contact angle measurement, and in vitro release of GL13K. The results demonstrated that peptide GL13K releasing hydrogel was successfully modified onto the micro/nanostructured titanium and GL13K displayed an effective controlled release. In vitro cell experiments including cytoskeleton observation, cell viability, phosphatase activity, mineralization and the expression of osteogenic related genes proved that the peptide GL13K releasing hydrogel modified micro/nanostructured titanium had good biocompatibility, promoted osteoblast differentiation. In vitro antibacterial experiments showed that it also can prevent the growth of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria by the release of GL13K. This study demonstrates titanium surface modification that allows for the development of anti-bacterial titanium implants.