Cooperation effect of 4-vinylbenzeneboronic acid/methacrylic acid on affinity of capecitabine imprinted polymer for drug carrier

Cooperation effect of 4-vinylbenzeneboronic acid (4-VPBA) and methacrylic acid (MAA) was first used to improve the affinity of molecularly imprinted polymer (MIP) for drug delivery. The MIP was prepared using capecitabine (CAP) as template, MAA as functional monomer, 4-VPBA as auxiliary monomer, and trimethylolpropane trimethacrylate as cross-linker. The preparation conditions of the MIPs were optimized by investigating the types of functional monomers, the types of cross-linkers, the ratio of MAA to 4-VPBA, and the ratio of crosslinker to monomer. The results showed that the as-prepared MIP had the maximum imprinting factor of 4.03, which revealed this material had a specific recognition effect on the template molecules. Experiments with in vitro release indicated that the imprinted material released CAP stably for more than 10 h, while the nonimprinted polymer (NIP) released CAP only 4 h. In addition, the pharmacokinetics results from rats showed that the MIP was significantly superior to the NIP and CAP commercial drugs, and the plasma concentration of CAP reached the plateau between 3.0 and 9.0 h. These findings may extend the applicability of noncovalent molecular imprinting, particularly to the cases where the target molecule containing a cis-dihydroxy structure.