Related Experiment Video
Updated: May 3, 2026
Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages
Published on: December 10, 2013
Antifungal effect of titanium oxide nanoparticles on Candida glabrata internalized in human macrophages
María Elena Gómez-Hernández1, Shantal Lizbeth Baltierra-Uribe2, Juan Castillo-Cruz2
1Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Querétaro, Santiago de Querétaro, Mexico.
Background:
Candida glabrata (Nakaseomyces glabrata) is an emergent human fungal opportunist pathogen. Recently, it was considered by the WHO as a fungal priority pathogen due to the high percentage of mortality (20-50%) from invasive candidiasis. C. glabrata shows high resistance to azoles, and in recent years, echinocandin resistance has been rising. Additionally, C. glabrata can evade immunological responses and manipulate macrophage activity to survive within these immune cells successfully. Titanium oxide (TiO2) is a photocatalytic material with recognized antimicrobial properties with and without photoactivation. This study aimed to investigate the antifungal effect of TiO2 nanoparticles on the planktonic form of C. glabrata and on internalized C. glabrata in macrophages.
Methods:
TiO2 nanoparticles were synthesized by the sol-gel method and characterized by X-ray diffraction, Raman spectroscopy, and TEM. The effect of nanoparticles on C. glabrata was determined by quantification of Colony Forming Units and TEM. ROS levels were analyzed by NBT reduction, and the role of autophagy was determined by immunofluorescence and western blotting.
Results:
The nanoparticles synthetized are composed of a mixture of anatase and rutile phases with a quasi-spherical shape and a diameter range of 10-79 nm. These nanoparticles exhibit a significant effect on planktonic C. glabrata (approximately 90%) and a substantial reduction of fungal load (70-90%) in infected macrophages. Remarkably, the lower concentrations (1, 10, and 50 µg/mL) exhibited the best antifungal effect. Moreover, this impairment was associated with independent mechanisms of the ROS production, since at those concentrations, there was no increase in ROS levels, and the antifungal effect was also observed in darkness. The induction of autophagy observed in cells treated with 50 µg/mL nanoparticles suggests that this process is a potential mechanism responsible for TiO2 nanoparticles activity.
Conclusion:
TiO2 nanoparticles exhibited a high antifungal effect on both planktonic and internalized yeasts, suggesting that autophagy may be involved. Together, the findings highlight the potential therapeutic use of TiO2 nanoparticles in the treatment of fungal infections.
Insights
Titanium dioxide (TiO2) nanoparticles show significant antifungal effects against Candida glabrata, both in planktonic form and within macrophages. These nanoparticles offer a promising therapeutic strategy for combating invasive fungal infections.
Area of Science:
- Nanotechnology
- Mycology
- Materials Science
Background:
- Candida glabrata is a priority fungal pathogen causing invasive candidiasis with high mortality rates.
- C. glabrata exhibits resistance to common antifungal drugs like azoles and echinocandins.
- This opportunistic pathogen can evade immune responses and survive within macrophages.
Purpose of the Study:
- To investigate the antifungal efficacy of titanium dioxide (TiO2) nanoparticles against Candida glabrata.
- To evaluate the effect of TiO2 nanoparticles on planktonic C. glabrata and C. glabrata internalized within macrophages.
Main Methods:
- TiO2 nanoparticles were synthesized using the sol-gel method and characterized.
- Antifungal activity was assessed by quantifying Colony Forming Units and Transmission Electron Microscopy (TEM).
- Reactive Oxygen Species (ROS) levels and autophagy were analyzed.
Main Results:
- Synthesized TiO2 nanoparticles (anatase/rutile mix, 10-79 nm) effectively reduced planktonic C. glabrata by ~90%.
- TiO2 nanoparticles significantly reduced fungal load in infected macrophages (70-90%) at low concentrations.
- Antifungal effects were observed in darkness and were independent of ROS production, with autophagy induction noted at higher concentrations.
Conclusions:
- TiO2 nanoparticles demonstrate potent antifungal activity against planktonic and intracellular C. glabrata.
- Autophagy appears to be a potential mechanism underlying the antifungal action of TiO2 nanoparticles.
- TiO2 nanoparticles hold promise as a therapeutic agent for treating C. glabrata infections.
