Evaluation of tt-farnesol efficacy released by a novel controlled drug delivery system against pathogenic oral biofilms

Author(s)

Guilherme Roncari Rocha

• Document type: Master's Dissertation
• Press: Araraquara. 2021-06-17.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara
• Defense date: 2017-07-07
• Advisor: Marlise Inêz Klein Furlan

Abstract

The development of efficacious therapies to control oral biofilms is challenging. Topical agents used to treat or prevent oral diseases are generally not retained in the mouth for sufficient duration to exert their full therapeutic potential. Thus, novel strategies for biofilm control focused on retention and sustained delivery of active agents at the site where virulent biofilm develops are warranted. Therefore, nanoparticle-carriers (NPC) that bind avidly to hydroxyapatite, to tooth-pellicle and exopolysaccharides were developed. NPC contains pH-responsive elements that facilitate controlled-release of therapeutic agents. Therefore, the aim of this study was to evaluate the efficacy of topical treatment using farnesol loaded delivery system against pathogenic mixed-species biofilm of Streptococcus mutans and Candida albicans on different surfaces found in oral cavity. Therefore, mixed-species biofilms were formed on different surfaces: zirconia (LAVA Frame, 3M), acrylic resin (Lucitone 550, Dentsply) and hydroxyapatite (control). Six topical treatments were applied on different surfaces for 5 minutes: PBS (phosphate buffer used to prepare NPC); NPC-free; NPC + tt-farnesol; Vehicle (phosphate buffer with 15% ethanol used to prepare tt-farnesol); and tt-farnesol. The assays performed were: biomass, watersoluble and -insoluble exopolysaccharides, pH of spent media, microbial population, and 3D architecture of biofilms by confocal microscopy. Nanoparticulate treatments associated with tt-farnesol showed a reduction in the amount of S. mutans population and amounts of water-soluble exopolysaccharides (which provides protection for biofilm), independent of the substrate. In addition, this treatment had no effect on C. albicans population and on amounts of water-insoluble exopolysaccharides. Therefore, the reduction of bacterial population and of protection of the microbial population by water-soluble exopolysaccharides demonstrated that the treatment associated with nanoparticle technology is efficient. However, it is necessary to improve the strategy to reduce also the fungal population and the water-insoluble exopolysaccharides (AU)

• FAPESP's process: 15/03424-1 - Evaluation of antimicrobial agents efficacy released by a novel drug delivery system against pathogenic oral biofilms
• Grantee: Guilherme Roncari Rocha
• Support Opportunities: Scholarships in Brazil - Master