Fabrication and characterization of triple nanobioceramic composite foam

In this study, triple nanobioceramic composite foam consisting of bioactive glass (BG), forsterite, and hydroxyapatite (HA) with highly porous structure and high mechanical strength was successfully fabricated via gelcasting method. The BG and forsterite were added to HA as second-phase ceramics to enhance simultaneously its bioactivity, biodegradability, and mechanical properties. The prepared foams have a crystallite size in the range 30-52 nm (while the crystallite size of initial HA and forsterite powders is about 22 nm), pore size in the range 100-300 mu m, and total and interconnected porosity upto 87% and 81%, respectively. The compressive strength measurements showed that the foams have an excellent compressive strength (2.19-3.68 MPa), which is appropriate for load-bearing tissue engineering applications and is close to the compressive strength of spongy bone. In vitro tests proved the good bioactivity and resorbability of the foams. The resulting composite foams have similar chemical composition to the mineral phase of bone and it is possible to optimize the ratio of BG phase to ceramic phases for achieving appropriate mechanical strength, bioactivity, and biodegradability level needed for different applications.