In Vitro and In Vivo Biocompatibility Of ReOss? in Powder and Putty Configurations

摘要

This study evaluated comparatively two configurations (powder and putty) of a compositebiomaterial based on PLGA (Poly(lactide-co-glycolide)anoescale hydroxyapatite(ReOss?, Intra-Lock International) through microscopic morphology, in vitro cytotoxicity,biocompatibility and in vivo response as a bone substitute. SEM and EDS characterizedthe biomaterials before/after grafting. Cytocompatibility was assessed with murine pre-osteoblasts. Osteoconductivity and biocompatibility were evaluated in White New Zealandrabbits. Both configurations were implanted in the calvaria of eighteen animals in non-critical size defects, with blood clot as the control group. After 30, 60 and 90 days, theanimals were euthanized and the fragments containing the biomaterials and controlswere harvested. Bone blocks were embedded in paraffin (n=15) aiming at histologicaland histomorphometric analysis, and in resin (n=3) aiming at SEM and EDS. Beforeimplantation, the putty configuration showed both a porous and a fibrous morphologicalphase. Powder revealed porous particles with variable granulometry. EDS showed calcium,carbon, and oxygen in putty configuration, while powder also showed phosphorus.After implantation EDS revealed calcium, carbon, and oxygen in both configurations.The materials were considered cytotoxic by the XTT test. Histological analysis showednew bone formation and no inflammatory reaction at implant sites. However, thehistomorphometric analysis indicated that the amount of newly formed bone was notstatistically different between experimental groups. Although both materials presentedin vitro cytotoxicity, they were biocompatible and osteoconductive. The configurationof ReOss? affected morphological characteristics and the in vitro cytocompatibility butdid not impact on the in vivo biological response, as measured by the present model.