Surface Functionalisation of Hyaluronic Acid-Based Foams with TiO₂ via ALD: Structural, Wettability and Antimicrobial...

The aim of this study was to evaluate the effect of surface modification of porous hyaluronic acid (HA)-based materials with a titanium dioxide (TiO₂) layer deposited via atomic layer deposition (ALD) on the selected structural, physicochemical, and antimicrobial properties of materials intended for applications in regenerative medicine. The obtained HA-based materials, enriched with silk and elastin, were analyzed in terms of their rheological behavior, wettability, solubility, and resistance to colonization by clinically relevant bacterial pathogens (Staphylococcus aureus, Klebsiella pneumoniae) and environmental filamentous fungi (Aspergillus niger, Chaetomium globosum). The results demonstrated that even a thin, continuous TiO₂ layer formed after 200 ALD cycles reduced the hydrophilicity of the foams, indicating improved durability in aqueous environments. Microbiological tests confirmed enhanced antimicrobial properties of the foams after TiO₂ modification-showing inhibition of both tested bacterial strains and C. globosum within 24 h. These findings suggest that surface functionalization of hyaluronic acid-based foams with a TiO₂ layer can improve both their environmental stability and, to some extent, reduce microbiological risk, while preserving the layered-porous structure of the foams, which is advantageous for biomedical applications.