Biosignal responsive drug delivery system by using bioactive polymer/ceramic composite bone cement

研究了生物活性骨水泥配方对人工合成或天然聚合物与磷灰石相关陶瓷粉复合骨水泥中头孢氨苄(CEX)释放的影响。双酚-α-甲基丙烯酸缩水甘油酯(Bis-GMA)、甲基丙烯酸三乙二醇酯(TEGDMA)树脂和含有CEX的磷灰石和硅灰石微晶玻璃(A-WGC)粉末与Bis-GMA/TEGDMA树脂混合后5min内硬化，抗压强度有望高于聚甲基丙烯酸甲酯水泥。生物活性骨水泥微丸在pH值为7.25和37℃的模拟体液中体外释药持续2周以上。药物释放速率随混合物中CEX含量的增加而增加。所有的药物释放都在初始阶段符合Higuchi方程，但在后期不符合。随着羟基磷灰石在骨水泥表面的析出，药物释放速率降低。这些结果表明，生物活性骨水泥的CEX释放率可以通过改变骨水泥体系中药物的量来控制。

Effect of formulation of the bioactive bone cements on cephalexin (CEX) release from cement consisting of synthesis or natural polymers and apatite related ceramics powder was investigated. Bisphenol-α-glycidyl methacrylate (Bis-GMA), triethylene-glycol dimethacrylate (TEGDMA) resin and apatite- and wollastonite-containing glass-ceramic (A-W GC) powder containing CEX powder hardened within 5 min after mixing with Bis-GMA/TEGDMA resin, and furthermore its compressive strength was expected to be higher than that of polymethylmethacrylate cement. In vitro CEX release from bioactive bone cement pellets in simulated body fluid at pH 7.25 and 37℃ continued for more than 2 weeks. The drug release rate increased with increasing amount of CEX in the mixture. All of the drug release profiles the Higuchi equation at the initial stage, but not at later stages. As hydroxyapatite was precipitated out on the cement surface, the drug release rate decreased. These results suggest that the CEX release rate from bioactive bone cement could be controlled by varying the amount of drug in the cement system.