Enhancement of carbonate apatite scaffold properties with surface treatment and alginate and gelatine coating

Abstract

Carbonate apatite (CO3Ap) scaffolding has been widely used for bone repair and replacement due to its excellent osteoconductivity and resorbability in bone defects. However, the application of the porous scaffold has been limited by its brittleness. Here, CO3Ap scaffolds coated with 1, 3 and 5 wt% of sodium alginate (SA) and bovine gelatine (BG) were fabricated to improve the mechanical properties of the porous scaffold. Limited studies have been done on a CO3Ap scaffold coated with a natural polymer layer. Here, a CO3Ap scaffold was fabricated through the phase transformation from β-tricalcium phosphate (β-TCP) to CO3Ap using a hydrothermal method. Fourier-transform infrared (FTIR) analysis confirmed the presence of both SA and BG functional groups on the CO3Ap scaffold. Five wt% of SA and BG improved the compressive strength of the uncoated CO3Ap scaffold by 34% and 46%, respectively. The SA coating was found to enhance the compressive strength of the CO3Ap scaffold compared to the BG coating due to its high viscosity. Furthermore, the compressive strength of the scaffold increased by 40% after undergoing a silanization process and being coated with SA. These results indicate that the use of a silane treatment improved the chemical bonding between the CO3Ap scaffold and SA coating. This process increased the adhesion between the SA coating and the scaffold and improved the compressive strength.