Preparation and evaluation of paclitaxel-imprinted polymers with a rosin-based crosslinker as the stationary phase in high-performance liquid chromatography

In this study, molecularly imprinted polymer (MIP) microspheres for paclitaxel (PTX) were prepared by microsuspension polymerization and used as a stationary phase in high-performance liquid chromatography (HPLC) for the separation of PTX and its structural analog docetaxel (DOC). For MIP synthesis, ethylene glycol maleic rosinate acrylate and 2-vinylpyridine were used as the cross-linker and functional monomer, respectively. MIP microspheres were characterized by scanning electron microscopy, laser granulometry, nitrogen sorption porosimetry, and thermogravimetric analysis. Results indicated the formation of regular MIPs with an even pore size distribution; furthermore, these MIPs exhibited excellent thermal stability. These MIP microspheres were packed into a stainless steel column for the selective separation of PTX and DOC. Under optimum chromatographic conditions, a separation factor of 2.54 and an imprinting factor of 2.37 were obtained. In addition, thermodynamic data obtained from van't Hoff plots revealed enthalpy-driven separation and higher contribution from functional group interactions as compared with that from steric complementary interactions. Microcalorimetry was employed to investigate the binding mechanisms of the analytes on the MIP surface.