Genotoxicity and mutagenicity of poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and PHBV radiopaque apatite (PHBV-La20AP) scaffolds

• Grant number: 16/25025-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2017
• End date: December 31, 2017
• Field of knowledge: Biological Sciences - Genetics - Mutagenesis
• Principal Investigator: Ticiana Sidorenko de Oliveira Capote
• Grantee: Joissi Ferrari Zaniboni
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Scaffolds based on poly(hydroxybutyrate-co-valerate) (PHBV) and PHBV-apatite radiopaque (PHBV-La20AP) were developed by the Institute of Chemistry of Araraquara - UNESP, using the additive manufacturing method (3D printing). In recent years, PHB has gained prominence over other resorbable polymers, but because of certain disadvantages, polyhydroxyvalerate has been added to improve the ductility and processability, which allowed poly(hydroxybutyrate-co-valerate) (PHBV) to become the focus of extensive research for biomedical applications. Lanthanum (La), a rare earth element, presents radiopaque characteristics, was used to allow a clear view in radiographs, in order to facilitate the diagnostic imaging. PHBV and PHBV-La20AP were previously evaluated by XTT and Clonogenic Survival tests and no cytotoxic effects were observed. The objective of this study is to continue the evaluation of PHBV and PHBV-La20AP, verifying the genotoxic (Comet Assay - EC) and mutagenic potential (Micronucleus Test - MN) for possible application in tissue engineering as biomaterial for bone repair, allowing visualization in medical and dental radiographs. CHO-K1 cells will be seeded (5×104 - EC; 37×104 - MN). Eluates will be prepared according to ISO 10993-12 in different concentrations (100%, 75%, 50%, 25%). The eluates will remain in contact with the cells for 24 hours. For the Micronucleus test, the Nuclear Division Index, the frequency of binucleate cells with micronuclei and the frequency of micronuclei will be evaluated. For the Comet Assay, DNA damage will be analyzed by an image analysis system. Three independent replicates will be performed for each assay. The obtained data will be submitted to the tests of variance (ANOVA) and if they are parametric, the Tukey and Dunnett tests will be done. If the data doesn't meet the requirements for parametric analysis, non-parametric tests will be applied. The level of significance adopted will be 5%. (AU)