Improving affinity of beta-cyclodextrin-based molecularly imprinted polymer using room temperature ionic liquid

摘要

This paper reported the facile method of improving the affinity of beta-cyclodextrins (beta-CD)-based molecularly imprinting system by using the effect of interaction of beta-CD and room temperature ionic liquids (RTILs). The molecularly imprinting polymers (MIPs) of beta-CD matrices were prepared with beta-CD, as functional monomer, hexanethylene diisocyante as crosslinker, and using aesculin as a model molecule in a RTIL (1-butyl-3-methylimidazolium tetrafluoroborate) of porogen. The RTILs/DMSO-based MIP (or NIP) showed smaller surface areas but greater pore size than the RTILs/DMSO-free MIP (or NIP). The equilibrium adsorption experiment indicated that the imprinting factor for the beta-CD-based MIP prepared with RTILs was 2.25 and 1.19 for the controlled MIP prepared without RTILs. In addition, the values of effective diffusivity (D-eff) of aesculin (AN) obtained from the RTILs-assisted beta-CD MIP (10(-16) cm(2)/s) was about seven times smaller than those from the RTILs-free controlled beta-CD MIP, although the values of free diffusivity (D) of AN were all found in the order of 10(-13) cm(2)/s. When used as release material, the relative bioavailability of the beta-CD-based MIP prepared in RTIL displayed a markedly higher value of 399.7% than that of the commercial AN tablet. On the contrary, the beta-CD-based non molecularly imprinted polymer (NIP) prepared in RTILs, beta-CD-based MIP prepared in non-RTILs and beta-CD-based NIP prepared in non-RTILs was only 88.6%, 179.3% and 157.0%, respectively. The results indicated that using RTIL as porogen is an effective approach to improving affinity of beta-CD-based MIP.