Evaluation of the efficacy of L-Dopa and P11-4 in dentin and pulp regeneration in tooth-on-a-chip model

• Grant number: 24/14503-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2025
• End date: June 30, 2028
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Fernanda Miori Pascon
• Grantee: Ranam Moreira Reis
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Dental caries are highly prevalent in childhood, and if left untreated, can cause pain and impact the quality of life. New dental biomaterials, such as adhesives incorporated with bioactive molecules and biochemical precursors, may represent a promising approach to promoting the regeneration of the dentin-pulp complex. Technologies like tooth-on-a-chip allow for detailed study of these processes, advancing biomedical research and the development of new therapies. The study aims to evaluate the efficacy of Levodopa (L-Dopa), a fundamental biochemical precursor in the production of various neurotransmitters such as dopamine, and P11-4, a self-assembling peptide capable of forming a fibril matrix that can serve as a scaffold for tissue regeneration, using a methacrylate-methacrylamide hybrid adhesive containing L-Dopa associated with P11-4, in a tooth-on-a-chip model. This is an in vitro study where the efficacy of L-Dopa and P11-4, as well as a methacrylate-methacrylamide hybrid adhesive containing L-Dopa and P11-4, will be tested in dentin and pulp regeneration and their interaction with stem cells from the apical papilla (SCAPs). Human dentin fragments (0.7 x 0.5 x 0.5 mm) will be subjected to artificial caries lesion formation using carboxymethylcellulose acid gel for 5 days. After that, the dentin fragments will be inserted into tooth-on-a-chip devices (30 x 10 x 30 mm), made of polydimethylsiloxane with four reservoirs for cell culture medium. Through the presence of SCAPs and a hybrid adhesive with L-Dopa/P11-4, the device will replicate the dentin-pulp interface. The experimental groups will be L-Dopa, P11-4, L-Dopa/P11-4 and medium containing SCAPs, Hybrid Adhesive + L-Dopa, Hybrid Adhesive + P11-4, Hybrid Adhesive + L-Dopa/P11-4, adhesive without incorporation as a negative control, and Scotchbond Universal Plus - 3M adhesive as a positive control. The assays will be conducted independently, with SCAPs differentiation observed by immunofluorescence; growth factor concentration (TGF-¿1 and VEGF) measured by ELISA and expressed in pg/mL; cytotoxicity of the actives using the alamarBlue¿ method and expressed as a percentage relative to control groups; proteolytic activity in the hybrid layer after contact with the adhesive using immunofluorescence with laser scanning confocal microscopy, and mineralization verification by alizarin red staining in cell culture, using absorbance obtained by spectrophotometer as a comparison parameter. The data will be analyzed for normality and homoscedasticity, parametric (ANOVA) or non-parametric (Kruskal-Wallis) statistical tests according to the normal or non-normal distribution of the data, respectively (¿=5%).