Data from: A novel strategy based on Zn(II) porphyrins and silver nanoparticles to photoinactivate Candida albicans

Data supporting the figures presented in the research article "A novel strategy based on Zn(II) porphyrins and silver nanoparticles to photoinactivate Candida albicans"

Background: Photodynamic inactivation (PDI) has been an attractive alternative to treat Candida albicans infections, especially considering the spread of resistant strains. The combination of the photophysical advantages of Zn(II) porphyrins (ZnPs) and the plasmonic effect of silver nanoparticles (AgNPs) has the potential to further improve PDI. In this context, this study aimed to evaluate PDI action in C. albicans using ZnTnHex-2-PyP⁴⁺ or ZnTE-2-PyP⁴⁺ associated with AgNPs. Methods: AgNPs stabilized with polyvinylpyrrolidone (PVP) were chosen to allow for (i) overlap between NP extinction and ZnP absorption spectra and (ii) favor AgNPs-ZnPs contact; prerequisites for exploring the plasmonic effect. Optical and zeta potential (ζ) characterizations were performed, and ROS generation was also evaluated. Yeasts were incubated with ZnPs alone or in combination with AgNPs (AgNPs-ZnPs systems), at various concentrations of ZnPs and two proportions of AgNPs, then irradiated with a blue LED. Interactions between yeasts and the systems (ZnP alone or AgNPs-ZnPs) were evaluated by fluorescence microscopy. Results: Subtle spectroscopic changes were observed for ZnPs after association with AgNPs, and the ζ analyses confirmed AgNPs-ZnPs interaction. PDI using ZnP-hexyl (0.8 µM) and ZnP-ethyl (5.0 µM) promoted a 3 and 2 log₁₀ reduction of yeasts, respectively. On the other hand, AgNPs-ZnP-hexyl (0.2 µM) and AgNPs-ZnP-ethyl (0.6 µM) systems led to complete fungal eradication under the same parameters and lower porphyrin concentrations. An increase in the ROS level was observed when ZnPs were associated with AgNPs. Enhanced interaction of yeasts with AgNPs-ZnPs was observed, when compared with ZnPs alone. Conclusion: We hypothesize that the plasmonic effect combined with the greater interactions between cells and AgNPs-ZnPs systems resulted in an efficient and improved C. albicans yeast PDI, encouraging further developments toward inactivation of resistant Candida spp.