Degradation properties of magnesium oxychloride bone cement composite modified by hydroxypropyl methylcellulose and KH2PO4

In this study, we report the effects of hydroxypropyl methylcellulose (HPMC) and KH2PO4 on the water resistance of magnesium oxychloride cement (MOC), a novel bone cement composite. Different MOC samples were soaked in simulated body fluid (SBF). After soaking for 7–56 d, the surfaces of the experimental group (1 wt.% HPMC/2 wt.% KH2PO4-MOC) and control group (2 wt.% KH2PO4-MOC) appeared pores, which grew with increasing immersion time. Compared with the control group, the experimental group had smaller pore sizes and a denser surface. Furthermore, the compressive strength in the experimental group increased from 35.1 ± 1.9 MPa to 41.8 ± 2.3 MPa, and the softening coefficient increased from 0.34 to 0.45. Thus, HPMC could improve the water erosion resistance of the MOC. The implantation study of the femoral defects in rats showed that the sample modified by 1 wt.% HPMC/2 wt.% KH2PO4 had good biocompatibility and biodegradability. The results indicate that the modification of MOC with HPMC and KH2PO4 is a promising technique to form biodegradable bone repair materials and has good application prospects in the field of biomedical materials.