庆大霉素和O-羧甲基壳聚糖对硫酸钙骨水泥改性研究

Modification of calcium sulfate bone cement by gentamicin and oxygen-carboxymethylated chitosan

目的通过添加O-羧甲基壳聚糖(oxygen-carboxymethylated chitosan,O-CMC)和庆大霉素对硫酸钙骨水泥(calcium sulfate cement,CSC)进行改性,提高其在骨修复领域应用的可行性。方法通过在CSC液相中添加不同浓度O-CMC(0.1wt%、0.3wt%、0.5wt%、0.7wt%、1.0wt%),制备O-CMC/CSC。通过可注射性、抗压强度、降解率、模拟体液pH值及Ca^(2+)浓度测试、成分与形貌表征观察以及细胞毒性测试,分析O-CMC浓度对CSC在可注射性、抗压强度、降解行为及成骨活性方面的影响。综合以上检测指标,确定最佳性能的O-CMC/CSC,并以此复合不同浓度庆大霉素(0.5wt%、1.5wt%、2.5wt%),探究其抗压强度和抗菌性。结果 O-CMC/CSC可注射时间均超过5 min,且随O-CMC浓度的增加而显著延长(P<0.05)。改良后的骨水泥抗压强度介于11~18 MPa之间,0.5wt%O-CMC/CSC抗压强度最高(P<0.05)。O-CMC/CSC降解速率随O-CMC浓度增加而呈减小趋势,但组间比较差异无统计学意义(P>0.05)。浸泡液pH值变化在7.2~7.4之间,Ca^(2+)浓度稳定在6~8 mmol/L。成分与形貌表征观察显示,相比于CSC,O-CMC/CSC在模拟体液中的诱导矿化能力更强,具有更好生物活性。综合以上检测指标结果,确定0.5wt%O-CMC/CSC性能最佳,加入庆大霉素后其抗压强度均大于5 MPa且具有抗菌性。结论 O-CMC能够有效提高CSC的可注射性、抗压强度和成骨活性,加入庆大霉素后复合骨水泥具有抗菌性。

Objective To extend its application in the field of bone repair by adding oxygen-carboxymethylated chitosan （O-CMC） and gentamicin for modification of the calcium sulfate cement （CSC）. Methods The O-CMC/CSC was prepared by adding O-CMC with different concentrations （0.1wt%, 0.3wt%, 0.Swt%, 0.7wt%, and 1.0wt%） in the CSC liquid phase. The effect of O-CMC on the CSC was evaluated by testing the in）ectability, compressive strength, degradation rate, pH value, cytotoxicity and osteogenesis. After the optimal concentration of O-CMC was determined, gentamicin with different concentrations （0.5wt%, 1.5wt%, and 2.5wt%） was added in the O-CMC/CSC, and then the compressive strength and antibacterial properties were investigated. Results After adding O-CMC in the CSC liquid phase, the injection time of O-CMC/CSC was increased to more than 5 minutes; it significantly prolonged with increased concentration of O-CMC （P〈0.05）. The compressive strength of the modified bone cement was in the range of 11-18 MPa and it was the highest when the concentration of O-CMC was 0.5wt% （P〈0.05）. The degradation rate of O-CMC/CSC was not influenced obviously by O-CMC （P〉0.05）. The pH value was in the range of 7.2-7.4 and Ca2＋ concentration was in the range of 6-8 mmol/L. In vitro mineralization experiment indicated that the inducedmineralization ability of O-CMC/CSC was much higher than that of pure CSC. The 0.5wt% O-CMC/CSC had the best performance; the compressive strength of the composite bone cement was above 5 MPa after gentamicin was added, which had antibacterial effect. Conclusion O-CMC is able to effectively improve the injection, compressive strength, and osteogenic activity of CSC; in addition, antibacterial properties is obtained in the CSC after adding gentamicin.