Synthesis and characterization of hierarchical mesoporous-macroporous TiO₂-ZrO₂nanocomposite scaffolds for cancellous bone tissue engineering applications

Bone tissue engineering has been introduced several decades ago as a substitute for traditional grafting techniques to treat bone defects using engineered materials. The main goal in bone tissue engineering is to introduce materials and structures which can mimic the function of bone to restore the damaged tissue and promote cell restoration and proliferation. Titania and zirconia are well-known bioceramics which have been widely used in tissue engineering applications due to their unsurpassed characteristics. In this study, hierarchical meso/macroporous titania-zirconia (TiO2-ZrO2) nanocomposite scaffolds have been synthesized and evaluated for bone tissue engineering applications. The scaffolds were produced using the evaporation-induced self-assembly (EISA) technique along with the foamy method. To characterize the samples, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), simultaneous thermal analysis (STA), and Brunauer-Emmett-Teller (BET) analysis were performed. The results showed that TiO2-ZrO2 scaffolds can be produced after sintering the samples at 550°C for 2 h. Among samples with different weight percentages of zirconia and titania, the sample containing 13 wt.% zirconia was considered as the optimum sample due to its structural integrity. This scaffold had pore size, pore wall size, and mesopores in the range of 185±66 μm, 15±4 μm, and 7-13 nm, respectively. The specific surface area obtained from the BET theory, total volume, and mean diameter of pores of this sample was 13.627 m2g1-, 0.03788 cm3g-1, and 11 nm, respectively. The results showed that the produced scaffolds can be considered as the promising candidates for cancellous bone regeneration.