Preparation of hollow magnetic molecularly imprinted polymer and its application in silybin recognition and controlled release.

In this study, a new type of drug delivery carrier, the hollow magnetic silybin molecularly imprinted polymer (HMMIP) with a unique core-shell structure where the hollow magnetic core Fe3O4 was wrapped by mesoporous silica and imprinted layer, was prepared from methacrylic acid (MAA, functional monomer), ethylene glycol dimethacrylate (EGDMA, cross-linker), and silybin (a drug template) by reverse atom radical transfer polymerization method (RATRP), and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller analysis (BET). Its adsorption performance was evaluated by the isotherm/kinetic models and the selectivity for silybin with 15.40 mg g-1 of adsorption capacity and 2.13 of selectivity factor α, respectively. The drug release experiment showed the prepared polymer had the properties of silybin sustained release agent, because it could last to release silybin for 36 h in the medium of pH 2.0 at physiological temperature. In addition, the resuability experiment indicated the imprinted material had the good stability and reproducibility. So HMMIP should be of the potential value applied in drug delivery in the future.