An in-vitro study of antibacterial, cytocompatibility and physicochemical properties of TiO₂-ZnO nanocomposite

A TiO₂-ZnO nanocomposite was synthesized using a sol-gel and peptization method for photocatalytic antibacterial applications. The resultant TiO₂-ZnO exhibited a spherical morphology, encompassing particles with a size below 10 nm. The XRD pattern and the distinct particle boundaries illustrate the good crystalline quality of the particles with anatase and wurtzite phases being evident. The TiO₂-ZnO exhibits excellent colloidal stability, indicated by a zeta potential of 65 mV, which prevents particle aggregation and ensures dispersion uniformity over an extended period of 24 months. The antibacterial characteristic of the TiO₂-ZnO were tested using clinical strains of K. pneumoniae (ESBL), E. coli (CRE), E. coli (ESBL), E. faecium (VRE), P. aeruginosa (MDR), A. baumanii (MDR), and K. pneumoniae (CRE). The structural characteristics contribute to a highly active surface area for photocatalytic reactions, with 99.9% disinfectant of all clinical bacterial strain colonies being observed after 5 min exposure time, except for the E. coli strains (CRE and ESBL) which required 30 min. The cytocompatibility profile test (MTT), clonogenicity and cell proliferation assay were performed using either L929 mouse fibroblasts or V79 cells. These demonstrated an absence of cytotoxic effects, underscoring the TiO₂-ZnO nanocomposite’s safety features. Given its excellent antibacterial properties coupled with its non-cytotoxic nature, the TiO₂-ZnO nanocomposite emerges as a highly promising candidate for a disinfectant coating material for healthcare fields.