This study aimed to evaluate the antifungal activity of titanium dioxide nanoparticles (TiO₂ NP) against Candida tropicalis ATCC 750 strain under both dark and UV light activation conditions. For this purpose, anatase phase TiO₂ nanoparticles were applied to C. tropicalis suspensions at four different concentrations (125, 250, 500, and 1000 µg/mL) and for four different durations (15, 30, 45, and 60 min). The experiments were conducted under two conditions: dark environment and UVA (365 nm- 15 cm distance) activation. Antifungal activity was determined by colony counting at the end of the exposure periods. Log reduction and percentage reduction were calculated. The UV+TiO₂ combination exhibited significantly higher antifungal activity compared to the dark condition. With UV activation, complete elimination (100% mortality, 2.48 log reduction) was observed at 45 minutes at a TiO₂ concentration of 1000 µg/mL and at 60 minutes at a concentration of 500 µg/mL. Under dark conditions, a maximum reduction of 0.84 log (85.7% reduction) was observed at 1000 µg/mL after 60 minutes; complete elimination was not observed at any concentration. Only 0.27 log reduction (46.7% reduction) was achieved after 60 minutes in the group treated with UV alone. Photocatalytic activity was found to be approximately 9 times stronger than the effect of UV alone. This study provides valuable evidence that UV-activated TiO₂ nanoparticles exhibit potent photocatalytic antifungal activity against C. tropicalis, with the potential to achieve complete elimination at high concentrations. The results obtained demonstrate that TiO₂ NPs have the potential to serve as an alternative antifungal strategy in the treatment of C. tropicalis infections, where resistance is becoming an increasingly significant problem.
Pınar Küce Çevik (Tue,) studied this question.