Self-assembled thermoresponsive micelles of poly(N-isopropylacrylamide-b-methyl methacrylate).
Self-assembled thermoresponsive micelles of poly(N-isopropylacrylamide-b-methyl methacrylate).
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DOI：
10.1016/j.biomaterials.2005.09.028
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发表时间：
2006-03
期刊：
影响因子：
14
通讯作者：
Hua Wei;Xianzheng Zhang;Ying Zhou;Si-Xue Cheng;R. Zhuo
中科院分区：
文献类型：
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作者：
Hua Wei;Xianzheng Zhang;Ying Zhou;Si-Xue Cheng;R. Zhuo
为了实现以被动方式的空间特异性与刺激响应靶向机制的组合，使用聚（N-异丙基丙烯酰胺-b-甲基丙烯酸甲酯）（PNIPAAm-b-PMMA）的嵌段共聚物制备温度响应性聚合物胶束。以芘为荧光探针，用荧光光谱法测定了两亲性嵌段共聚物在水溶液中的临界胶束浓度。透射电子显微镜图像显示，这些纳米粒子的形状是规则的球形。通过尺寸分析确定的胶束尺寸约为190 nm。通过光学吸收测量和动态光散射（DLS）观察到，胶束响应于通过聚合物外壳的温度循环显示可逆的分散/聚集，PNIPAAm的LCST为约33°C。抗炎药物醋酸泼尼松作为模型药物负载在聚合物纳米粒中。考察了醋酸泼尼松的体外释药行为，发现醋酸泼尼松胶束壳层结构的温度响应性结构变化表现出明显的温度响应性快/慢转换行为。这种胶束的可逆和敏感的温度响应可能提供机会，构建一个新的药物输送系统结合局部热疗。
To achieve a combination of spatial specificity in a passive manner with a stimuli–response targeting mechanism, a temperature-responsive polymeric micelle was prepared using block copolymers of poly(N-isopropylacrylamide-b-methyl methacrylate) (PNIPAAm-b-PMMA). The critical micelle concentration of amphiphilic block copolymers in aqueous solution was determined by fluorescence spectroscopy using pyrene as a fluorescence probe. Transmission electron microscopy images showed that these nanoparticles were regularly spherical in shape. Micelle size determined by size analysis was around 190nm. The micelles showed reversible dispersion/aggregation in response to temperature cycles through an outer polymer shell lower critical solution temperature (LCST) for PNIPAAm at around 33°C, observed by optical absorbance measurements and dynamic light scattering (DLS). The anti-inflammation drug prednisone acetate was loaded as the model drug in the polymeric nanoparticles. In vitro release behavior of prednisone acetate was investigated, which showed a dramatic thermoresponsive fast/slow switching behavior according to the temperature-responsive structural changes of a micellar shell structure. The reversible and sensitive thermoresponse of this micelle might provide opportunities to construct a novel drug delivery system in conjunction with localized hyperthermia.