The rise of antibiotic-resistant bacteria poses significant health challenges, leading to drug treatment failures. Titanium dioxide (TiO₂) nanoparticles (NPs) possess unique properties such as antibacterial, cytotoxic, optical, catalytic characteristics. This study synthesizes TiO2 NPs using Calotropis procera leaf extract having particles size 10-50 nm. Antimicrobial efficacy was assessed against gram-negative and gram-positive bacteria using Kirby’s disc diffusion assay at various concentrations. Cytotoxicity on cancer cell lines was evaluated via MTT assay and histological examinations determined the impact of TiO₂ NPs on kidney and liver tissues of albino mice. The study found increased serum biochemical parameters (ALT, AST, ALP, urea), while creatinine and total bilirubin levels were significantly decreased (p<0.005). Maximum inhibition zones were observed at 40mg/ml, with antibacterial activity ranked as S. aureus > E. coli > K. pneumoniae > E. faecalis. Toxicity increased with higher nanoparticle concentrations, evidenced by cell swelling, hepatocyte necrosis, glomerulus degeneration, and nephritic tubule damage. The green-synthesized TiO₂ NPs showed effective antibacterial agents for future biomedical applications.

Index Terms- Titanium dioxide, Calotropis procera, Antibacterial, HepG2, MTT assay