Provided is a carrier that can achieve both the stability of a biological drug in blood and its release in a target cell. A pharmaceutical composition of the present invention includes: a polymer unit α having a hydrophilic polymer chain segment and a cationic polymer chain segment; a polymer unit β having a hydrophilic polymer chain segment and a cationic polymer chain segment; and a drug. The polymer unit α and the polymer unit β form a micelle by being radially arranged so that the cationic polymer chain segments are directed inward and the hydrophilic polymer chain segments are directed outward, the micelle encapsulating the drug. The cationic polymer chain segment of the polymer unit α has a phenylboronic acid group in a side chain, and the cationic polymer chain segment of the polymer unit β has a phenylboronic acid binding site in a side chain, and the phenylboronic acid group and the phenylboronic acid binding site form a cross-linked structure that is disintegrable under an acidic environment or in the presence of a substance capable of competitive binding.
本发明提供了一种载体,它既能实现
生物药物在血液中的稳定性,又能实现其在靶细胞中的释放。本发明的药物组合物包括:具有亲
水性聚合物链段和阳离子聚合物链段的聚合物单元 α;具有亲
水性聚合物链段和阳离子聚合物链段的聚合物单元 β;以及药物。聚合物单元 α 和聚合物单元 β 通过径向排列形成胶束,使阳离子聚合物链段向内,亲
水聚合物链段向外,胶束包裹药物。聚合物单元 α 的阳离子聚合物链段的侧链上有一个苯
硼酸基团,聚合物单元 β 的阳离子聚合物链段的侧链上有一个苯
硼酸结合位点,苯
硼酸基团和苯
硼酸结合位点形成交联结构,在酸性环境下或在有竞争性结合物质存在的情况下,该结构可以分解。