Modification of titanium implants by bioactive and antibacterial zinc gallate metal organic framework

Abstract

Bone diseases like rheumatoid arthritis or osteoporosis often lead to severe bone fractures requiring artificial implants. Titanium, especially its Ti6Al4V alloy, is favored for orthopedic and dental implants due to its exceptional properties. However, titanium implants face challenges like delayed osseointegration and bacterial susceptibility. Surface functionalization techniques, including antimicrobial coatings and drug delivery systems, aim to address these issues. Metal organic frameworks (MOFs), especially bio-MOFs, offer potential for implant modification due to their large surface area and biocompatible components. Here, we developed a MOF layer on titanium implants using gallic acid and Zn2+ ions to enhance antibacterial properties and bioactivity. The obtained materials were characterized using various research techniques. Using FT-IR microscopy, it was confirmed that the MOF is evenly distributed over the entire surface of the material. The MOF layer affects the hydrophilicity of the surface and the contact angle is approximately 60°. Additionally, tests for HAp growth, BSA adsorption and antibacterial performance were conducted. Our findings suggest that the MOF layer improves implant performance and biocompatibility by inducing HAp growth, enhancing protein sorption, and inhibiting microbial growth by about 20–40 % depending on the microorganism.