NIR-Responsive ZIF-8 Metal-Organic Framework Nanohybrids with Photothermal, Antimicrobial, and Osteoinductive Properties to Prevent Implant Infection.

Abstract

Current treatments for bone injuries face notable limitations such as adverse reactions to implant materials and increased risks of infection. There is an essential need for a therapeutic that will address these issues and decrease recovery times. Herein, a multifunctional nanohybrid zinc-based metal-organic framework integrated with gold nanoparticles (Au@ZIF-8) is synthesized to promote antibacterial and osteogenic benefits. Au@ZIF-8 is capable of converting light energy into heat and has demonstrated its ability to increase the surrounding temperature by ≈30 °C. As a result, Au@ZIF-8 has exhibited bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) upon exposure to near-infrared (NIR) irradiation. Concurrently, Au@ZIF-8 sustains the release of zinc ions from the nanohybrid for the potential of bone repair. When combined with a gelatin-based hydrogel, Au@ZIF-8 significantly elevated osteogenic gene expression and promoted preosteoclast differentiation through the sustained zinc ion release, as opposed to a gel-only control. The potential of the multifunctional nanohybrid is further demonstrated as a coating material for titanium orthopedic implants to introduce antibacterial properties and promote osteogenic differentiation of preosteoblasts for bone healing. Given its excellent antibacterial in response to NIR irradiation and osteogenic abilities, Au@ZIF-8 is a promising photothermal therapy for bone injuries.