化疗药复合聚甲基丙烯酸甲酯骨水泥理化性质研究

Physicochemical properties of polymethyl methacrylate bone cement compound with chemothera- peutic drugs

目的观察化疗药复合后对聚甲基丙烯酸甲酯（PMMA）骨水泥的理化性质的影响，探讨复合化疗药的PMMA骨水泥理化性能。方法将甲氨蝶呤（MTX）、表阿霉素（EPI）进行75℃热处理10min之后进行细胞毒性实验分析其活性改变。将MTX与PMMA以1％、2％、4％的质量比复合；EPI与PMMA以0．1％、0．2％、0．4％的质量比复合；MTX联合EPI与PMMA以1％＋0．1％、2％＋0．2％、4％＋0．4％的质量比复合，分别检测其机械性能及电镜下微结构改变。结果方差分析结果显示各组MTX和EPI热处理后，细胞毒性实验结果同对照组比较差异无统计学意义（P〉0．05）。MTX和EP1分别或联合与PMMA以质量比不高于4％和0．4％复合后，复合骨水泥各项机械强度性能指标均高于国际参考值。以抗压强度及抗弯模量为因变量，采用回归分析发现，MTX和EPI与PMMA复合质量比不影响抗压强度及抗弯模量（P〉0．05）。以抗弯强度为因变量，采用回归分析发现MTX与PMMA复合质量比不影响抗弯强度（P〉0．05）；EPI与PMMA复合质量比显著影响抗弯强度（P〈0．05，B=2315．305）。电镜下复合PMMA表面或断面上的不规则孔隙变浅变少。结论PMMA骨水泥聚合放热过程对MTX和EPI的活性无明显影响，复合MTX和EPI后对PMMA机械性能无明显不利影响，PMMA微结构孔隙可作为化疗药的良好载体。

Objective To investigate the influence of chemotherapeutic drugs on physicochemical properties of polymethyl methacrylate （PMMA） bone cement compound and the physicochemical properties of PMMA bone cement compound containing chemotherapeutic drugs. Methods The potency of methotrex- ate （MTX） and epirubicin （EPI） were analyzed by cytotoxicity experiment after thermal treatment at 75℃ for 10 min. MTX was mixed with PMMA by mass ratio of 1%, 2%, and 4% respectively, while EPI was mixed by 0. 1%, 0. 2%, and 0. 4% respectively. Both of MTX and EPI were mixed with PMMA by mass ratio of 1% ＋ 0. 1%, 2% ＋ 0. 2%, and 4% ＋ 0. 4%, of which bending strength, compressive strength and microstructure were detected respectively. Results As comparied with control group, the potencies of MTX and EPI were not significantly reduced after thermal treatment through the ANOVA analysis （ P 〉 0. 05）. Mechanical strength indexes of composite bone cement, mixed with either single or combination of MTX and EPI by corresponding mass ratio, were higher than the international reference value. In regression analysis, mass ratio of combined MTX and EPI with PMMA had no significant effect on compressive strength or composite bending modulus （ P 〉 0. 05 ）. Mass ratio of EPI and PMMA significantly affected compressive strength （P 〈0. 05, B =2 315. 305）, while mass ratio of MTX and PMMA did not significant- ly affect compressive strength （ P 〉 0. 05 ） by regression analysis. The irregular porosity on the surface of composite PMMA bone cement was reduced and became shallower. Conclusion The heat release of PMMA bone cement during polymerization had no significant effect on the vitalities of MTX and EPI, and the compound with MTX and EPI didn＇ t significantly change the mechanical properties of PMMA bone ce- ment. The microstructure porosity in PMMA bone cement could be used as a favorable and promising carri- er for chemotherapeutic drugs.