Desenvolvimento de membranas cerâmicas de Fosfato Tricálcico e Hidroxiapatita com adição de Manganês via Tape Casting para regeneração óssea guiada

Abstract

Materials composed by calcium and phosphorus have been widely studied for their chemical and biological similarity to bone tissue and their osteoconductibility, guiding osteoblastic cells by promoting bone neoformation. Because of their relatively low mechanical resistance, it becomes necessary to add biocompatible polymers that can optimize the conformation of these materials. Despite presenting good cellular response when entering in contact with the bone, studies indicate that cellular proliferation occurs slowly. A promising alternative to accelerate cellular proliferation is the addition of chemical elements such as manganese for its capability of influencing bone metabolism by stimulating the production of osteoblasts at the beginning of osteogenesis. In this context, Tape Casting is a widely used technique for producing thin, flat films with controlled thickness. The usage of this method in the development of biomaterials allows control of porosity, size and shape of pores, essential features of barrier membranes. In this paper, ceramic tapes based on tricalcium phosphate and hydroxyapatite of commercial and synthetic powders with and without the addition of manganese were developed using the Tape Casting method in order to evaluate which material presents fastest cell proliferation. Ceramic powders were analyzed by X-Ray Diffraction. Suspensions were characterized by rheological essay. Tapes were characterized by thermal analysis (DTA/TGA), X-ray diffraction (XRD), degree of tumescence, highresolution scanning electron microscopy (SEM-FEG), energy dispersive spectroscopy, Raman, bioactivity and cytotoxicity assays. The analyses performed sought to evaluate the potential usage of these tapes as bone dressings in order to improve bone metabolic activity. According to the rheologic study, the pseudoplastic behavior -adequate to the process of Tape Casting - was observed. Ceramic powders presented β- TCP phases, hydroxyapatite and manganese oxide. The degree of tumescence, thermal analysis and SEM images confirmed the material’s capacity of osteoconduction, as it was possible to observe the formation of Ca and P precipitates in the course of days. The samples showed resistant to water and thermal treatment and presented dense microstructure. Biocompatibility analyses showed excellent bioactivity responses and did not show toxicity, which is essential for usage in bone dressings.