DNA scaffolds for bone reconstruction in calvaria defects in rats

• Grant number: 22/08746-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2023
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Roberta Okamoto
• Grantee: Naara Gabriela Monteiro
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

This project will investigate the local action of DNA hydrogels, functionalized or not with biomolecules, in bone reconstructions from models of critical defect in rat calvaria. For this, 246 young adult male Wistar rats will be used. 36 rats will be destined to the analysis of biocompatibility through the insertion of biomaterials in the subcutaneous tissue of the animals. The experimental groups of the subcutaneous tests will be the following: DNA, AMTN (DNA + amelotin), PASP (DNA + aspartic acid). The animals will be euthanized 24 hours and 3 days after the placement of the biomaterial and the subcutaneous samples will be submitted to histological and immunohistochemical analysis. The other animals will undergo surgery for a critical defect in the calvaria (n = 210) and will be divided into the following experimental groups: CLOT, AUTO PT, DNA, AMTN, PASP. On day 0 the animals will undergo surgery for a critical calvaria defect. The euthanasia of the animals of the first period of euthanasia will occur 3 days after the surgery and the collected calvaria will be destined to the analyses: histological and immunohistochemical. The second period of euthanasia will be submitted to euthanasia 10 days after surgery and the samples will be destined for RT-PCR, histological, immunohistochemical and computed microtomography analyses. For animals in the third period of euthanasia, fluorochromes (20mg/kg) will be administered, with calcein 14 days after critical defect surgery and alizarin 24 days after surgery, and euthanasia will be performed 28 days after the procedure. surgery, the calvaria will be destined for the following analyses: RT-PCR, histological, immunohistochemistry, computed microtomography and confocal microscopy (reparational bone dynamics). The samples submitted to computed microtomography will be submitted to laboratory processing for calcified sections after due scanning, for further analysis by confocal microscopy. The quantitative data will be submitted to the homoscedasticity test for the selection of the appropriate statistical test (parametric or non-parametric), with a significance level of 5%.