Synergistic effects of wheat gluten and poly (γ-glutamic acid) on physicochemical properties of bioglass modified beta-tricalcium phosphate bone cement

Beta-tricalcium phosphate (beta-TCP) based cements are a popular bone filling material due to their good compatibility, biodegradation, osteoconductivity and osteoinductivity. However, several inherent limitations of current available formulations of beta-TCP based cements restrict their applications in repairing of load-bearing bone defects. With the aim to improve mechanical properties and modify the hydration mechanism, a novel beta-TCP based bone cement was developed by the modification with different proportions of bioglass (BG) nanospheres, wheat gluten (WG) and poly (gamma-glutamic acid) (PGA). Effects of WG and PGA on the anti-washout ability, compressive strength, biodegradability, in vitro mineralisation capability and cytocompatibility of BG-modified beta-TCP bone cements were investigated. Results indicated that the introduction of WG and PGA could greatly enhance the handling performances of 50 wt.% BG nanospheres modified beta-TCP bone cements (denoted as 50BG-beta-TCP). Meanwhile, compared with 50BG-beta-TCP (8.8 +/- 0.9 MPa), the compressive strength of WG-50BG-beta-TCP (PGA) increased to 53.1 +/- 4.1 MPa after setting for 5 days at 37celcius. Furthermore, the extract solutions of these prepared cements exhibited good cytocompatibility to MC3T3-E1 cells. Therefore, the combination of WG and PGA was supposed to be a new strategy for developing injectable bone cement with good handling performances and mechanical and biological properties for repairing the load-bearing defects.