DNA scaffolds as a strategy for the "drug delivery" of strontium in critical defects in rat calvaria: Evaluation of biomineralization responses

• Grant number: 23/08734-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2023
• End date: February 28, 2025
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Roberta Okamoto
• Grantee: Tatiany Aparecida de Castro
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Around 2.2 million bone transplants are performed annually in clinical practice, which not only affects the quality of life and general health status of patients, but also represents a great economic burden for health systems. We will evaluate the regenerative potential of strontium-functionalized DNA hydrogels, through immunohistochemistry, PCR, microtomography and fluorochrome analyses, in the repair process of critically sized bone defects in rat calvaria that are dependent on the stimulation of biomaterials for bone formation. After approval by the Ethics Committee, 44 male Wistar rats will be divided into two groups, in which DNA will represent the animals that will receive the DNA hydrogel without functionalization and DNA-Sr the animals that will receive strontium-functionalized DNA hydrogels. They will be subdivided according to the analyzes and the period of euthanasia. At time zero, the rats will undergo surgery to obtain the bone defect in the calvaria. Once the bone defect is made, the biomaterial will be placed inside it according to the group to which the animal belongs. The 10D subgroup will be euthanized 10 days after surgery and the collected parts will be analyzed by Histology, Immunohistochemistry and PCR. The 28D subgroup will be euthanized after 28 days and histological and immunohistochemical analyses, PCR, micro-CT and fluorochromes. The 60D subgroup will be euthanized after 60 days and will have the same analyzes as the 28D subgroup. For the analysis by fluorochromes, an intramuscular injection of calcein will be performed, in the 28D group 14 days after surgery and in the 60D group after 45 days. Alizarin red will be applied 24 days after surgery in the 28D group and 55 days after surgery in the 60D group. The euthanasia of these animals will occur by anesthetic overdose.