Preparation and characterization of gelatin-chitosan-nanoβ-TCP based scaffold for orthopaedic application

The primary aim of this study was to fabricate gelatin/chitosan/beta-TCP (GCT) composite scaffold to improve its compressive mechanical behaviour and in-vivo biocompatibility with predictable degradation rate. Beta tricalcium phosphate (beta-TCP) powder was synthesized in size range between 70-100 nm using aqueous precipitation route at a fixed Ca/P molar ratio of 1.5:1 at pH 10 and after subsequent heat treatment of as precipitated powder at 800 degrees C for 4 hours. The composite scaffolds were fabricated using solid-liquid phase separation of the slurry containing gelatin, chitosan, beta-tricalcium phosphate in varying proportion and subsequent lyophilisation of the phase separated mixture. The prepared scaffolds exhibited high porosity (>80%) with pore sizes ranging between 78-382 mu m as determined using Hg-porosimetry. SEM result revealed that incorporation of beta-TCP to the extent of 30 wt% resulted in well-shaped and uniformly distributed interconnected pores of average pore size of 120 +/- 18.6 mu m in it. Compressive strength of the scaffolds was increased from 0.8 MPa to 2.45 MPa on increase in beta-TCP content from 10 wt%-30 wt% in the prepared scaffold. Human Umbilical Cord derived mesenchymal stem cells (MSCs) exhibited higher degree of lamellopodia and fillopodia extensions and better spreading behaviour onto GCT30 scaffold. MTT assay and immunocytochemistry studies with cultured MSCs revealed that GCT30 scaffolds were more conducive to MSC's proliferation and differentiation into osteoblast lineage. In vivo implantation of GCT30 scaffold subcutaneously into mice did not indicate any significant inflammatory reaction, but ongoing vascularization.