Antimicrobial TiO2 nanocomposite coatings for surfaces, dental and orthopaedic implants

Abstract

Engineering of self-disinfecting surfaces to constrain the spread of SARS-CoV-2 is a challenging task for the scientific community because the human coronavirus spreads through respiratory droplets. Titania (TiO₂) nanocomposite antimicrobial coatings is one of the ideal remedies to disinfect pathogens (virus, bacteria, fungi) from common surfaces under light illumination. The photocatalytic disinfection efficiency of recent TiO₂ nanocomposite antimicrobial coatings for surfaces, dental and orthopaedic implants are emphasized in this review. Mostly, inorganic metals (<i>e.g</i>. copper (Cu), silver (Ag), manganese (Mn), <i>etc</i>), non-metals (<i>e.g</i>. fluorine (F), calcium (Ca), phosphorus (P)) and two-dimensional materials (<i>e.g</i>. MXenes, MOF, graphdiyne) were incorporated with TiO₂ to regulate the charge transfer mechanism, surface porosity, crystallinity, and the microbial disinfection efficiency. The antimicrobial activity of TiO₂ coatings was evaluated against the most crucial pathogenic microbes such as <i>Escherichia coli,</i> methicillin-resistant <i>Staphylococcus aureus</i>, <i>Pseudomonas aeruginosa</i>, <i>Bacillus subtilis, Legionella pneumophila, Staphylococcus aureus, Streptococcus mutans,</i> T2 bacteriophage, H1N1, HCoV-NL63, vesicular stomatitis virus, bovine coronavirus. Silane functionalizing agents and polymers were used to coat the titanium (Ti) metal implants to introduce superhydrophobic features to avoid microbial adhesion. TiO₂ nanocomposite coatings in dental and orthopaedic metal implants disclosed exceptional bio-corrosion resistance, durability, biocompatibility, bone-formation capability, and long-term antimicrobial efficiency. Moreover, the commercial trend, techno-economics, challenges, and prospects of antimicrobial nanocomposite coatings are also discussed briefly.