Smart/Stimuli-Responsive Antimicrobial System for Soft Tissue Integration. Antibacterial coating validation in animal model

• Grant number: 24/14872-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: June 30, 2025
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Érica Dorigatti de Avila
• Grantee: Maria Eduarda Fiorentino Ferreira de Andrade
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Associated research grant: 18/20719-3 - A novel antimicrobial drug-delivery coating for percutaneous implant devices, AP.JP

Abstract

The feasibility of our proposed approaches is based on our previous studies (de Avila et al., 2019; Verza et al. 2021), including our preliminary outcomes detailed in the scientific report. We have already confirmed the succeeded multilayer system through both polyelectrolytes: poly (acrylic acid) (PAA) and poly(l-lysine) (PLL), in ten double layers (de Avila et al., 2019). We have also validated the drug incorporation method into the layer-by-layer system (LbL), through the synthesis of a hydrophilic drug with anionic beta cyclodextrin (BCD) (Verza et al., 2021) and the responsive film onto the LbL system with methacrylic acid (MAA). The exciting outcomes encouraged us to proceed with the studies and translate the power of antimicrobial multilayer systems in meaningful biomedical applications. Here, we are proposing to extend the information obtained from the laboratory in rats to prove the antimicrobial activity of LbL/TCBCD with and without the smart/responsive MAA-based film coating Ti discs in a rat subcutaneous infection model designed for our research group. A detailed multilayer coating characterization will be performed by different microscopy and spectroscopy approaches to prove the reproducibility physical and chemical properties, previously obtained. A subcutaneous infection model was designed for our research group to better respond to our question. Initially, control (commercial pure Ti) and experimental samples (LbL/TC¿CD and LbL/TC¿CD/MAA) will be incubated with a polymicrobial saliva community for 16 hours at 37oC under anaerobic conditions. Afterward, washed-PBS samples will be randomly inserted into 3 unconnected subcutaneous pouches in the backs of 18 rats. The discs and the surrounding soft tissue will be firstly retrieved with a punch. The discs will be immediately submerged in culture medium for quantitative and qualitative analysis of viable colonies. Since the immune response to tissue injury determines the outcome of the healing process, soft tissue surrounding the discs will be processed for non-decalcified histology and immunofluorescence staining assessments.