Bioactive tricalcium silicate/alginate composite bone cements with enhanced physicochemical properties.

Previous studies have shown that tricalcium silicate bone cements possess good bioactivity and appropriate degradation rate. However, they also showed some weaknesses such as poor washout resistance, formability and injectability, which have seriously hindered their clinical applications. The purpose of this study was to develop a new type of bone cements-tricalcium silicate/sodium alginate (C S/SA) composites by utilizing the interaction of Ca ions with SA molecules, in which an interpenetrating double-network of calcium hydrate silicate (CSH) and alginate hydrogel was formed to enhance the washout resistance, formability, injectability and compressive strength of C S. The results confirmed that the washout resistance, formability and injectability of C S could indeed be greatly enhanced by the introduction of SA. In addition, the compressive strength of the C S/SA composite cement with an optimum composition could reach 54 MPa, which was significantly higher than that of C S (i.e., 35.3 MPa). Moreover, the C S/SA composite cements retained the bioactivity of C S, such as the activity to induce apatite formation in simulated body fluid and to promote cell proliferation. All these results indicate that the C S/SA composite cements hold great promise as a new type of bone repair materials for further in vitro and in vivo studies. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 237-244, 2018.