Bi-functionalization of titanium with a mixture of peptides for improving its osteogenic and antibacterial activity

Poor osteointegration and implant infection are two of the main causes that hinder the success of clinical implants. In order to enhance the osteogenesis and antibacterial activity of titanium, BFP-1 and GL13K peptides were immobilized on the surface of micro/nanostructured titanium using dopamine as a coupling mechanism. Successful construction of BFP-1 and GL13K peptides on the micro/nanostructured titanium surfaces was demonstrated by several material characterization methods including scanning electron microscopy (SEM), atomic force microscope (AFM), water contact angle measurements and X-ray photoelectron spectroscopy (XPS). The micro/nanostructured titanium modified with BFP-1 and GL13K peptides promoted osteoblast differentiation as demonstrated by cell staining, cell viability, alkaline phosphatase activity, mineralization detection and qRT-PCR of osteogenesis-related genes. The in vitro study exhibited antibacterial properties after culturing S. aureus and E. coli on micro/nanostructured titanium modified with BFP-1 and GL13K peptides for 6 h and 24 h. This study demonstrates that surface-modified titanium implants can simultaneously promote bone growth and provide antibacterial capabilities.