Fabrication and characterization of porous biphasic β-tricalcium phosphate/carbonate apatite alginate coated scaffolds

In this research, biphasic β-tricalcium phosphate/carbonate apatite (β-TCP/CO3Ap) scaffolds incorporated with alginate were fabricated. Sodium alginate was extracted from local brown seaweed, Sargassum polycystum via calcium alginate process. Biphasic β-TCP/CO3Ap scaffolds were fabricated by polymer reticulate method. β-TCP slurry was infiltrated into the polyurethane foam (PU) foam, then sintered up to 1300 °C, soaked for 4 h and immediately quenched in still air to form biphasic β-TCP/α-TCP scaffold. Biphasic β-TCP/α-TCP scaffold was then transformed to biphasic β-TCP/CO3Ap scaffold by dissolution-precipitation reaction with 1 M of NaHCO3 at 170 °C for 1, 3 and 5 days. Biphasic β-TCP/CO3Ap scaffold from 5 days dissolution-precipitation reaction was chosen to incorporate with 1%, 3% and 5% of sodium alginate, respectively, as it has the highest composition of CO3Ap phase. FTIR and FESEM analysis confirmed the presence of characteristic functional groups of sodium alginate. Mechanical strength of biphasic β-TCP/CO3Ap scaffold improved by increasing the concentration of sodium alginate. The highest mechanical strength achieved was 26.38 kPa for biphasic β-TCP/CO3Ap scaffold with 5% sodium alginate coating and it was chosen to further study with the addition of 1%, 3% and 5% microspheres. FESEM analysis confirmed the attachment of microspheres on the surface of alginate/biphasic β-TCP/CO3Ap scaffold was successful.