Desenvolvimento e caracterização de microesferas de fosfato de cálcio bifásico / Development and characterization of biphasic calcium phosphate microspheres

AUTOR(ES)
FONTE

IBICT

DATA DE PUBLICAÇÃO

04/06/2012

RESUMO

The biphasic calcium phosphate is greatly applied in the replacement of osseous tissues and as dermal fillers due to its chemical similarity with the mineral part of bone and teeth. Due to this similarity, the calcium phosphates present, among other important properties, high biocompatibility, bioactivity and/or osteoconduction. They do not induce inflammatory or immune reaction, acute or chronic, causing minimal irritation that is limited to the local contact, and cause minimal allergies. Among the calcium phosphates, the apatites form the major part of the ceramics of biological interest, and can be composed of hydroxyapatite and beta-tricalcium phosphate, namely biphasic calcium phosphate. This material is classically available in ceramic blocks, dense or porous, or in particulate form (granules, powders and colloids). Granules and powders with spherical shape are preferred because they conform better in irregular implantation sites, and offer more satisfactory rheological properties when used in injectable products. Several methods for microparticles production have been reported, some employing expensive equipments and raw materials, and other presents the disadvantage of using highly toxic organic solvents, in at least one processing step, which need to be removed. In this study a production route of particulate biphasic calcium phosphate bioceramics with spherical shape was developed, eliminating the use of equipment and raw materials of high cost and toxic substances, thereby reducing the number of process steps and cost. The process was based on liquid immiscibility, generating a water/oil emulsion, using a mixture of gelatin solution and biphasic calcium phosphate (dispersed phase) and food grade canola oil (continuous phase). The microparticles obtained were physically, chemically and biologically characterized, and their incorporation and drugs release potential was also evaluated. The results showed that the improved method produced polydisperse microparticles without residues of chemicals used in processing, spherical shape and porous structure. The microspheres produced showed no cytotoxic effects for the cell line studied and showed potential for drugs incorporation and release of the antibiotic gentamicin.

ASSUNTO(S)

microesferas fosfato de cálcio hidroxiapatita emulsificação porosidade microspheres calcium phosphate hydroxyapatite emulsification porosity

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