Analysis of the effect of nucleases on the degradation of extracellular DNA in the matrix of peri-implant biofilms

• Grant number: 24/21721-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Caroline Dini
• Grantee: Vitoria Gabriela Cícero da Silva
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The extracellular DNA present in the extracellular matrix of subgingival biofilms in peri-implant infections is a critical factor in biofilm stability. In addition, different types of non-canonical extracellular DNA structures may be present in biofilms and may promote resistance to degradation. Thus, evaluating which nuclease has the greatest potential for matrix degradation and application in peri-implant biofilms could help in the treatment of mucositis and peri-implantitis. However, there are still no studies evaluating the important role of this constituent of the matrix for biofilms of peri-implant diseases. Therefore, this study aims to evaluate the effect of DNase I and micrococcal nucleases on the degradation of extracellular DNA in the matrix of subgingival peri-implant biofilms, using a multi-species in vitro model that mimics the microbial composition of peri-implant infections. To this end, three groups will be used: (1) subgingival biofilm 96 h (control); (2) subgingival biofilm 96 h + exposure to DNase I for 2 h; (3) subgingival biofilm 96 h + exposure to micrococcal for 2 h. The degradation of the extracellular matrix and the effects on the biofilm will be evaluated using the crystal violet staining assay to assess biofilm biomass, confocal laser microscopy to check the influence of nucleases on biofilm structure, dry weight, exopolysaccharide dosage and extracellular DNA dosage to assess biofilm degradation after exposure to nucleases. The quantitative data will be subjected to appropriate statistical analysis with a significance level of 5%.