Characterization of polymicrobial biofilm of Paracoccidioides brasiliensis and Pseudomonas aeruginosa and treatment with chitosan nanoparticles loaded with Brown propolis extract.

• Grant number: 25/03663-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Ana Marisa Fusco Almeida
• Grantee: Isabela Coronado
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Considering the complications of infections caused by biofilm-forming microorganisms and their resistances, the incidence of chronic paracoccidioidomycosis in Brazil, as well as the high rates of coinfections by Pseudomonas aeruginosa (Pa), makes new investigations urgent, to understand the mixed biofilms formed by these pathogens. In coinfection cases, only opportunistic infections have been reported, but there is still no evidence of these associations in vivo in biofilm formation, although both Paracoccidioides brasiliensis (Pb) and Pa are biofilm-forming microorganisms. On the other hand, the complexity of these infections demands new formulations for safer and more effective treatments, and nanoparticles are excellent alternatives. The goal of this project is to characterize the polymicrobial biofilms formed by the combination Pb and Pa and develop a chitosan nanoparticle capable of carrying Brown Propolis, a natural product with anti-inflammatory, antimicrobial, immunomodulatory, and wound-healing properties, to combat the agents responsible for pulmonary infections. To this end, monomicrobial and polymicrobial biofilms will be developed in different situations, like pre-formed polymicrobial biofilms of Pb followed by the addition of Pa, the reverse, and simultaneous formation, similarly, the antibiofilm activity of the formulations will be tested in these situations. Additionally, human lung cells will be used to assess vitro cytotoxicity, and the goal is to understand the behavior of the combined biofilms and obtain a promising formulation for therapy.