In Vitro and In Vivo Evaluation of Composite Scaffold of BCP, Bioglass and Gelatin for Bone Tissue Engineering

In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and NHydroxysuccinamide( EDC-NHS). The initial average pore size of the scaffold ranged from 300 to 700 mu m, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1pre- osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCPBG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater ( geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).