Pluronic嵌段共聚物胶束作为靶向药物载体

聚氧乙烯 聚氧丙烯 聚氧乙烯 (PEO PPO PEO)三嵌段共聚物 (商品名为Pluronics)在水溶液中能自发生成多分子聚集的胶束 ,这些胶束主要以疏水的PPO嵌段为内核 ,PEO嵌段环绕在外构成外壳 ,这种胶束可以有效地增溶油溶性药物。Pluronic嵌段共聚物无毒、无刺激、无免疫原性 ,胶束外壳的PEO嵌段能阻止血小板的聚集。胶束尺寸和病毒相仿 ,其大小适合在体内传输。初步尝试表明 ,胶束表面嵌上合适的抗体可以将增溶了模型药物的Pluronic胶束定向输送到动物脑部 ,从而提高了药效 ,降低了副作用。实验表明 ,Pluronic嵌段共聚物胶束可能成为将多种药物导向特定部位的有效载体。

Micellae of Pluronic Triblock Copolymers as Targeting Drug Microcarriers

Water soluble triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO),often denoted by PEO PPO PEO and commercially available as Pluronics,are an important class of nonionic macromolecular surface active agents.At suitable condition,these molecules of Pluronic block copolymers can spontaneously associate to form thermodynamically stable micellae in aqueous solution.Outer hydrophilic shell of such micelle is formed by nontoxic and nonimmunogenic PEO blocks.In Pluronic micellae,molecules of a drug can be incorporated into the inner hydrophobic core that is formed mainly by PPO blocks.In a majority of cases the size of Pluronic micellae (including those containing solubilized compounds) does not exceed the size of viruses.For targeting such microcontainers to a certain cell the Pluronic molecules are firstly conjugated with antibodies against a target specific antigen or with protein ligands selectively interacting with target cell receptors.The obtained conjugates are then incorporated into the drug containing micellae by simple mixing of the corresponding components.The present results show that Pluronic micellae may be good microcarriers for drug targeting.