Effect of phosphate glass reinforcement on the mechanical and biological properties of freeze-dried gelatin composite scaffolds for bone tissue engineering applications

Development of three-dimensional scaffolds is an important step in tissue engineering to repair, rebuild and regenerate damaged tissues. In this study, three dimensional porous gelatin (G) and phosphate glass (PG, 1 and 2 wt%) reinforced gelatin composite (GPG1 and GPG2) scaffolds were developed by freeze drying technique and their suitability as tissue engineering scaffolds was evaluated. FESEM images revealed the formation of an interconnected porous network with porosity above 70% and pore size around 100-500 mu m. The developed scaffolds showed swelling, biodegradation and apatite formation on the surface of the scaffolds. Four fold enhancement in compressive modulus was observed with the introduction of PG content in the gelatin matrix which increased further with increase in PG content. Cytotoxicity and cell attachment of the scaffolds were evaluated with MG-63 cells, which revealed non-toxic nature of the scaffold leading to attachment of cells. Cell proliferation of MG-63 on the scaffolds was examined by DNA quantification assay, which showed increased proliferation with PG content and further increase with increase in PG content. In order to evaluate the drug delivery performance of the PG reinforced gelatin composite, ciprofloxacin loaded gelatin and composite (GPG1 and GPG2) samples were prepared and release study was carried out. Prolonged and sustained release behaviour was observed for the PG reinforced gelatin scaffolds which were due to the strong interaction between the PG-ciprofloxacin-gelatin and Fickian diffusion mechanism was observed for GPG2 scaffold. The present study showed that the PG reinforced gelatin scaffold is a potential candidate for bone tissue engineering applications and also serve as drug delivery system.