Repairing effect of magnesium oxychloride cement modified by γ-polyglutamic acid and chitosan in osteoporotic bone defect

Magnesium oxychloride cement (MOC) has the advantage of high early strength. However, it has the defect of poor water resistance. Considering this performance, we use γ-polyglutamic acid (γ-PGA) and chitosan (CS) to modify MOC. The effects of γ-PGA and CS such as strength, in vitro degradation and in vitro bioactivity of MOC were studied. Based on the preparation of γ-PGA and CS modified MOC (γ-PGA/CS-MOC) composite bone cement, the strontium ranelate (SrR) was loaded on. The results showed that the softening coefficient of γ-PGA/3 wt.% CS-MOC after soaking in SBF for 28 d reached 0.48, while that of control group (without CS and γ-PGA) was only 0.35; Cell experiments indicated that SrR could promote differentiation into osteoblasts. After the γ-PGA/CS-MOC composite bone cement containing SrR was implanted into the osteoporotic bone defect for 12 w, it was found that the material was gradually absorbed and the new bone tissue grew. The results showed that SrR/γ-PGA/CS-MOC composite bone cement had a potential application prospect in the repair of osteoporotic bone defects.