A biocompatible hybrid material with simultaneous calcium and strontium release capability for bone tissue repair

Abstract

The increasing interest in the effect of strontiumin bone tissue repair has promoted the development of bioactive materialswith strontiumrelease capability. According to literature, hybrid materials based on the systemPDMS SiO2 have been considered a plausible alternative as they present a mechanical behavior similar to the one of the human bone. The main purpose of this study was to obtain a biocompatible hybrid material with simultaneous calcium and strontium release capability. A hybrid material, in the system PDMS SiO2 CaO SrO, was prepared with the incorporation of 0.05 mol of titanium per mol of SiO2. Calcium and strontium were added using the re spective acetates as sources, following a sol gel technique previously developed by the present authors. The ob tained samples were characterized by FT IR, solid state NMR, and SAXS, and surface roughness was analyzed by 3D optical profilometry. In vitro studieswere performed by immersion of the samples in Kokubo's SBF for differ ent periods of time, in order to determine the bioactive potential of these hybrids. Surfaces of the immersed sam ples were observed by SEM, EDS and PIXE, showing the formation of calcium phosphate precipitates. Supernatants were analyzed by ICP, revealing the capability of the material to simultaneously fix phosphorus ions and to release calcium and strontium, in a concentration range within the values reported as suitable for the induction of the bone tissue repair. The material demonstrated to be cytocompatible when tested with MG63 osteoblastic cells, exhibiting an inductive effect on cell proliferation and alkaline phosphatase activity.