PNIPAAM/SA pH-responsive microcapsules based on chemical and non-covalent crosslinking
A triple interpenetrating polymer network (IPN) with dual responses to temperature and pH was constructed based on chemical crosslinking and electrostatic interaction. In this IPN, CaCO 3 microspheres were used as the kernel and PNIPAAM/sodium alginate microcapsules were prepared by the inverse emulsion polymerization method. Research results demonstrated that CaCO 3 kernels were decomposed into Ca 2+ and CO 2 at pH 1.2. Such decomposition facilitated the formation of triple IPN of Ca 2+ crosslinking. Moreover, microcapsules were expanded by tension of CO 2 and the volume increased to 3.55 × 10 5 times that of the original microcapsules, with capsules remaining an intact morphology. These microcapsules loading doxorubicin hydrochloride (DOX) stability and responses to environment were investigated. No drug overflow was observed at pH 7.4, indicating the high stability of microcapsules. However, DOX was released gradually in the simulated human stomach acid with a weak solution of hydrochloric acid (pH 1.2, 37 °C). This showed that the prepared microcapsules were feasible for drug-loaded capsules and the controlled drug release behavior could relieve side effects of drugs to human body. Moreover, it will help to increase the drug utilization and realize accurate treatment.
危险品化学品经营许可证（带存储）