Biofabrication of titanium dioxide nanoparticles using leaf extract of Psidium guajava for advanced biomedical applications

This work employed Psidium guajava leaves for biogenic titanium dioxide nanoparticles (TiO₂NPs) by environmentally friendly techniques, which were comprehensively analyzed utilizing FT-IR, SEM, TEM, XRD, and EDX techniques. The analysis of TiO₂NPs indicated that the produced TiO₂NPs possess a crystalline structure in an average particle size varying from 35.4 to 65.9 nm. The antimicrobial findings indicated that TiO₂NPs had a significant antibacterial potential towards Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, which have minimum inhibitory concentrations varied from 500 to 250 µg/mL. Additionally, TiO₂NPs displayed a spectrum of anti-biofilm actions toward B. subtilis and P. aeruginosa. Moreover, TiO₂NPs exhibit significant antioxidant activity whose IC50 was 209.4 µg/mL utilizing DPPH technique. In addition, TiO₂NPs exhibit potential anticancer action against Caco-2 cell line whose IC50 was 102.3 µg/mL, by reducing it to 96.4 and 94.7 % at 1 mg/mL and 0.25 mg/mL, respectively. In summary, TiO₂NPs synthesized from P. guajava leaf extract show antibacterial, anticancer, and antioxidant effects with great biocompatibility. KEY WORDS: TiO₂NPs, Characterization, Antimicrobial, Anti-biofilm, Anticancer Bull. Chem. Soc. Ethiop. 2026, 40(1), 65-78. DOI: https://dx.doi.org/10.4314/bcse.v40i1.6