Infection Microenvironment‐Responsive Coating on Titanium Surfaces for On‐Demand Release of Therapeutic Gas and Antibiotic

• Published in: Advanced healthcare materials Vol. 13; no. 18; pp. e2304510 - n/a
• Main Authors: Wang, Kun, Rong, Fan, Peng, Haowei, Yuan, Zhang, Huo, Jingjing, Liu, Pengxiang, Ding, Rui, Yan, Cuiping, Liu, Guming, Wang, Tengjiao, Li, Peng
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-07-2024
• Subjects: antibacterial; Antibacterial activity; Antibiotics; Antiinfectives and antibacterials; Bacteria; Bacterial infections; Biological activity; Bone implants; Cell differentiation; Cell migration; Coating; Coatings; Coliforms; Controlled release; Defects; Differentiation (biology); E coli; Hydrogen sulfide; implant loosening; implant‐associated infection; Infections; Macromolecules; Microenvironments; Nanotubes; Orthopaedic implants; Orthopedics; Osseointegration; Sustained release; TiO2 nanotubes; Titanium; Titanium dioxide; Transplants & implants; implant‐associated infection; TiO2 nanotubes; antibacterial; implant loosening; osseointegration
• ISSN: 2192-2640; 2192-2659; 2192-2659
• DOI: 10.1002/adhm.202304510

Aseptic loosening and bacterial infection pose significant challenges in the clinical application of titanium (Ti) orthopedic implants, which are primarily caused by insufficient osseointegration and bacterial contamination. To address these issues, a responsive coating on Ti surface is constructed, which achieves enhanced osseointegration and infection elimination by on‐demand release of therapeutic gas hydrogen sulfide (H2S) and antibiotic. TiO2 nanotubes (TNT) are anodized on the Ti surface to enhance its bioactivity and serve as reservoirs for the antibiotic. An infection microenvironment‐responsive macromolecular H2S donor layer is coated on top of TNT to inhibit premature leakage of antibiotic. This layer exhibits a sustained release of low‐dosage H2S, which is capable of promoting the osteogenic differentiation and migration of cells. Moreover, the compactness of the macromolecular H2S donor layer could be broken by bacterial invasion, leading to rapid antibiotic release thus preventing infection. In vitro antibacterial experiments validates significant antibacterial activity of the coating against both Gram‐negative (Escherichia coli) and Gram‐positive bacteria (Staphylococcus aureus). Crucially, this coating effectively suppresses implant‐associated infection with 98.7% antibacterial efficiency in a rat femoral bone defect model, mitigates inflammation at the defect site and promotes osseointegration of the Ti orthopedic implant.
Antibiotic is preloaded into TiO2 nanotubes and sealed with a layer of macromolecular H2S donor. The osseointegration of implants could be enhanced by sustained release of H2S, mainly in promoting the osteogenic differentiation and vascularization. In the bacterial infection microenvironment, overexpressed thiol‐containing compounds could trigger the responsive release of antibiotic to effectively inhibit the infection.