Fabrication and characterization of porous β-tricalcium phosphate scaffolds coated with alginate

All porous materials have a common limitation which is lack of strength due to the porosity. In this study, two different methods have been used to produce porous β-tricalcium phosphate (β-TCP) scaffolds: liquid-nitrogen freeze casting and a combination of the direct-foaming and sacrificial-template methods. Among these two methods, porous β-TCP scaffolds with acceptable pore size and compressive strength and defined pore-channel interconnectivity were successfully fabricated by the combined direct-foaming and sacrificial-template method. The average pore size of the scaffolds was in the range of 100-150 µm and the porosity was around 70%. Coating with 4 wt% alginate on porous β-TCP scaffolds led to higher compressive strength and low porosity. In order to make a chemical link between the β-TCP scaffolds and the alginate coating, silane coupling agent was used. Treated β-TCP scaffold showed improvements in compressive strength of up to 38% compared to the pure β-TCP scaffold and 11% compared to coated β-TCP scaffold.