In Vitro and In Vivo Evaluation of a New Hydrogel Containing Association Between Lipidic Nanoparticles Containing Vitamin E and Hybrid Recombinant Protein for Protection Against Erosive Demineralization

• Grant number: 24/20622-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: April 30, 2027
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: João Guilherme Medeiros Leite
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated research grant: 19/26070-1 - Modulation of acquired enamel pellicle to control dental mineral loss: unravelling mechanisms to make therapies possible, AP.TEM

Abstract

The presence of the acquired enamel pellicle (AEP) plays a crucial role in protecting against erosive tooth wear (ETW). With advances in omics techniques, acid-resistant proteins have been identified in the AEP, encouraging the development of "acquired pellicle engineering" strategies. These strategies aim to enrich the AEP with proteins that have a high affinity for hydroxyapatite, remaining adhered even after exposure to acidic challenges. Among these proteins, our group has recently developed CaneStat, a recombinant hybrid protein resulting from the fusion of CaneCPI-5, a recombinant phytocystatin derived from sugarcane, and a phosphomimetic peptide containing 15 amino acids from the N-terminal region of statherin, with serines 2 and 3 replaced by aspartic acid residues to mimic phosphorylation (Statpep). This fusion made the new recombinant protein resistant to AEP removal by both extrinsic (characteristic of CaneCPI-5) and intrinsic erosive acids (characteristic of Statpep).Recently, vitamin E has been studied for its ability to protect against initial erosive demineralization, with a mechanism of action associated with its diffusion into the lipids of the basal layer of the AEP, reducing lipid degradation. Studies combining vitamin E and CaneCPI-5 have shown a synergistic effect, regardless of the timing of application relative to AEP formation. However, the isolated application of each substance is not ideal from a clinical perspective. Therefore, the objective of this study is to develop a poloxamer-based hydrogel (a triblock copolymer with a hydrophobic central portion and hydrophilic side chains) capable of simultaneously incorporating CaneStat and lipid nanoparticles containing vitamin E. The hypothesis is that this hydrogel can diffuse through the lipids of the AEP, promoting effective distribution of both substances in the basal layer and allowing interaction and aggregation of acid-resistant proteins, even when applied after pellicle formation. The hydrogel will be tested for its protective potential against initial enamel erosion in both in vitro and in vivo studies, as well as its impact on AEP composition in vivo.