pH/temperature-sensitive hydrogel-based molecularly imprinted polymers (hydroMIPs) for drug delivery by frontal polymerization

Frontal polymerization was successfully utilized, for the first time, to obtain pH/temperature-sensitive hydrogel-based molecularly imprinted polymers (hydroMIPs). The polymerization reaction can be completed in 20 min. By this approach, hydroMIPs were synthesized using a mixture of gatifloxacin (template), N-isopropylacrylamide, acrylic acid and N,N′-methylenebisacrylamide. The influence of template concentration and the crosslinker amount on the imprinting effect of the hydroMIPs was investigated. The textural and morphological parameters of the hydroMIPs were also characterized by mercury intrusion porosimetry, DSC, and scanning electron microscopy. The gatifloxacin-imprinted polymer formed in frontal polymerization displayed high affinity than conventional thermal polymerization. The hydroMIPs were further evaluated as drug delivery devices and showed higher relative bioavailability than the corresponding non-imprinted polymer and hydroMIPs based on bulk polymerization from the results of the evaluation in vivo. The results suggest that frontal polymerization provides an alternative method to prepare hydroMIPs and may open up new perspectives in the field of MIPs.