BSA nanoparticles loaded-methylene blue for photodynamic antimicrobial chemotherapy (PACT): effect on both growth and biofilm formation by Candida albicans

Abstract

It has been demonstrated an increase in resistance of Candida albicans to conventional therapies, probably, due the indiscriminate use of the conventional antifungal drugs. In this aspect, the nanotechnology generates the possibility of creating new therapeutic agents. Thus, the objective of this paper was to produce and characterize a bovine serum albumin (BSA) nanoparticle encapsulated with Methylene Blue (MB). In addition, the effect of BSA nanoparticles encapsulated with MB (BSA-MB) was evaluated on both growth and biofilm formation by C. albicans by Photodynamic Antimicrobial Chemotherapy (PACT) protocols. The BSA-MB nanoparticles were prepared by the desolvation process. The nanoparticulate system was studied by steady-state techniques, scanning electron microscopy and their biological activity was evaluated in vitro both growth and biofilm formation by C. albicans. The synthetized BSA-MB nanoparticles were spherical in shape exhibiting a 100–200 nm diameter with a low tendency to aggregate (PDI values < 0.2). MB photophysical properties were shown to be preserved after BSA encapsulation. A significant reduction in C. albicans growth, after PACT was observed, in a dependent manner on MB-loaded in BSA nanoparticles concentration used. It was observed an inhibition of 23, 65 and 83% in the presence of MB-loaded in BSA nanoparticles 0.1, 0.5 and 1.0 µg.mL⁻¹, respectively. In addition, MB-loaded BSA nanoparticles 0.5 µg.mL⁻¹ were able to reduce both biofilm formation (80%) and the transition from yeast to filamentous form by C. albicans. The results presented here demonstrated a potentiation of the phototoxic effect of MB after BSA encapsulation, since the concentrations of MB-loaded BSA nanoparticles necessary to inhibits ∼50% of C. albicans development was 10 times minor than that observed for free MB. Taken together, these results suggest the potential of PACT, using MB-loaded BSA nanoparticles in inhibiting C. albicans development. The synthesis and design of BSA nanoparticles can be successfully applied for MB encapsulation and offer the possibility to drive the toxicity effect to a specific target, as an evaluation on both growth and biofilm formation by Candida albicans.

Keywords:

• BSA
• Candida albicans
• methylene blue
• nanoparticles
• antifungal therapy
• photodynamic antimicrobial chemotherapy

Acknowledgements

The authors would like to thank FAPESP, CNPq and CAPES for the financial support.

Disclosure statement

The authors have no financial, personal, or other conflicts of interest related to this work.

Ethical approval

In this study, all experiments were performed using Cultures of Candida albicans, therefore there was no need for approval by local authorities.

Informed consent

We have obtained permission from all the authors, we declare that the material has not been published in whole or in part elsewhere, the paper is not currently being considered for publication elsewhere.

Additional information

Funding

This work was supported by the Brazilian Agency CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) [project number 800985/2018-4]. This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001".