Research on a kind of biocompatible molecularly imprinted materials with silybin controlled release based on pH/temperature dual responses

Silybin, a hepatoprotective active natural ingredient, was used as the template, methyl acrylic acid (MAA) as the functional monomer, n-isopropyl acrylamide (NIPAm) as the thermal response monomer, magnetic core Fe3O4@CS@APTES@BiBB coated by biocompatible chitosan as the carrier, and a kind of silybin molecularly imprinted materials (MMIPs) based on pH/temperature dual responses were prepared by electron transfer activation regenerative catalyst atom transfer radical polymerization (ARGET ATRP). The synthesized material was characterized by FT-IR, TGA, SEM, XRD, VSM, and XPS, and the loading behavior of silybin in MMIPs could be explained by the pseudo-second-order kinetic model. The selectivity factor α (2.636) and the relative selectivity factor β (2.468) indicated MMIPs had good specific recognition ability for silybin. In addition, a series of experimental data displayed MMIPs had many other excellent characteristics such as adsorption property, swelling performance, biocompatibility, degradability, stability, reproducibility and so on. The cumulative release rates of MMIPs could reach 29%, 23% and 25% in the media of pH 1.0, 7.4 and 8.2 at 37.5 °C, resepectively, and when the temperature was raised to 43 °C, the release rate of MMIPs in solution (pH 7.4) reached 49%, which indicated that the carrier material had good pH/temperature dual responses.