Fabricação de biocerâmicas de matriz porosa com estrutura em alumina, recobrimento superficial de fosfato de cálcio e zinco incorporado à superfície

Abstract

There is an increasing demand for synthetic bone replacement materials, resulting from the limited supply of autograft materials and increased health risks associated with the use of allografts. A suitable scaffold material exhibiting adequate mechanical and biological properties is required to enable tissue regeneration. The processing technique used for fabrication of macroporous ceramics involved the preparation of ethanolic slurry from mixture of Al2O3 powder, dispersing agents and binder. Alumina porous bodies were fabricated by the polymer foam replication process, where polyurethane foams were infiltrated with optimized slurries, followed by the removal of excess slurryand burning out of the polymer to leave a ceramic replica of the polyurethane. After sintering, the resultant porous alumina bioceramic was characterized in terms of the porous microstructure. To bioactivate the scaffold a biomimetic method, consisting in the immersion of samples in SBF and other process of coating the alumina bodies byimpregnating with calcium phosphate ceramics/PVA slurry were used. After surface treatment the substrates were immersed into ethanolic solution containing zinc to introduce it as coating on the surface substrates for potential use in bone repair applications. Results presented have show the fabrication of porous alumina ceramics with varying pore morphologies characterised by spherical pores measuring between 350 and 550mm in diameter. Compressive strenght results for porous scaffold produced with alumina powder achieve 3,34MPa and we have succeeded in coating alumina substrates with calcium phosphate