聚焦超声控制交联聚(甲基丙烯酸甲酯-丙烯酸丁酯)/介孔二氧化硅复合材料的形状记忆和药物释放

High Intensity Focused Ultrasound Mediated Shape Recovery and Drug Delivery of Crosslinked Poly (Methyl Methacrylate-co-Butyl Acrylate)/Mesoporous Silica Composites

研究了交联聚(甲基丙烯酸甲酯-丙烯酸丁酯)/介孔二氧化硅复合材料在聚焦超声作用下的形状记忆性能和药物控制释放行为。实验表明,介孔二氧化硅的添加对复合材料声-热转换效率有一定提高作用,从而可以提高其形状回复率。另一方面,药物释放实验证实了此复合材料具有良好的聚焦超声控制药物释放性能,在多次聚焦超声ON/OFF转换下,药物呈现明显ON/OFF释放状态的转换,并且随着超声强度和聚合物基体中药物含量的增大,释放速率显著提高。与直接添加纯布洛芬相比,介孔二氧化硅的引入可以显著降低药物预释放量,提高释放可控性。

Crosslinked poly （methyl methacrylate-co-butyl acrylate）/mesoporous silica composites were synthesized by traditional radical polymerization under constant ultrasound and the shape memory performance and drug release behaviour under high intensity focused ultrasound （HIFU） were investigated. Based on the significant mechanical vibration and thermal effect under HIFU irradiation, the composites show excellent HIFU controlled shape recovery which makes it possible to mediate the shape recovery process spatially and temporarily. It is demonstrated that the introduction of mesoporous silica slightly enhances the thermal effect which attributes to the higher shape recovery ratio. On the other hand, the drug release behaviour under cycled HIFU exposure was studied. It shows that on- demand on/off drug release behaviour could be achieved by switching on or off the HIFU. And it is also found that both the increase of HIFU power intensity and the increase of total loaded drug amount can accelerate the drug release obviously. Compared to pure drug, loading ibuprofen into mesoporous silica can suppress the pre-release phenomenon and enhance the controllability of the drug release process.