DEVELOPMENT, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF POROUS POLYMETHYLMETACRYLATE CEMENT COMBINED TO DIFFERENT STRONCIUM FORMULATIONS

• Grant number: 17/26742-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2019
• End date: October 31, 2022
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Edgard Eduard Engel
• Grantee: Edgard Eduard Engel
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Ana Paula Ramos ; María Sol Brassesco Annichini

Abstract

Treatment of bone tumors, infection and trauma often creates bone defects that require filling to prevent fractures and promote bone remodeling. Due to the limitations of the autograft, several bone substitutes are being developed with different characteristics. PMMA-based porous cement, developed previously (FAPESP nº 2012/18965-0), presents mechanical characteristics similar to spongy bone, is biocompatible and non-toxic. In addition, in experimental animal studies, it presented high rates of osteointegration and bone invasion. In order to potentiate these biological features, in this study we propose, the combination of this cement with different forms and concentrations of strontium which is recognized stimulator of osteogenesis.Strontium phosphate and carbonate nanoparticles with varying stoichiometry that allow the controlled release of the metal will be synthesized and combined with the porous cement. In the chemical characterization the composition and crystalline structure of the particles will be evaluated, including the its elimination profile. In the physical characterization the morphology, density, curing time, maximum temperature during curing, mechanical and structural characteristics will be evaluated. In vitro assays will be also carried out in order to evaluate the cement´s cytotoxicity and the modulation of osteoinduction related genes. Moreover, the cement´s effects on osteoclast inhibition will be also studied. Osteointegration and bone invasion of the porous cement implanted in defects created in rabbit bones will be evaluated by histology, imunohistochemistry, micro-CT and mechanical push-off tests.We hope to develop a bone cement based on PMMA and porous strontium with interconnected, non-toxic and biocompatible macropores that can be modeled intraoperatively and eliminate strontium ions in a controlled manner. In addition, we expect this elimination of strontium to potentiate the ability of osteointegration and bone invasion. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

TOMAZELA, LARISSA; EUFRASIO CRUZ, MARCOS ANTONIO; NASCIMENTO, LARISSA AINE; FAGUNDES, CECILIA C.; DA VEIGA, MARCIA ANDREIA MESQUITA S.; ZAMARIOLI, ARIANE; BOTTINI, MASSIMO; CIANCAGLINI, PIETRO; BRASSESCO, MARIA SOL; ENGEL, EDGARD E.; et al. abrication and characterization of a bioactive polymethylmethacrylate-based porous cement loaded with strontium/calcium apatite nanoparticle. Journal of Biomedical Materials Research Part A, v. 110, n. 4, NOV 2021. (19/25054-2, 17/26742-4)