Molecular Imprinting of Cyclodextrin Supramolecular Hydrogels Improves Drug Loading and Delivery

Cyclodextrin-based controlled delivery materials have previously been developed for controlled release of different therapeutic drugs. In this study, a supramolecular hydrogel made from cyclodextrin-based macromonomers is subjected to molecular imprinting to investigate the impact on release kinetics and drug loading, when compared with non-imprinted, or alternately imprinted hydrogels. Mild synthesis conditions are used to molecularly imprint three antibiotics-novobiocin, rifampicin, and vancomycin-and to test two different hydrogel chemistries. The release profile and drug loading of the molecularly imprinted hydrogels are characterized using ultraviolet spectroscopy over a period of 35 days and compared to non-imprinted, and alternately imprinted hydrogels. While only modest differences are observed in the release rate of the antibiotics tested, a substantial difference is observed in the total drug-loading amount possible for hydrogels releasing drugs which has been templated by those drugs. Hydrogels releasing drugs which are templated by other drugs do not show improved release or loading. Analysis by FTIR does not show substantial incorporation of drug into the polymer. Lastly, bioactivity assays confirmed long-term stability and release of incorporated antibiotics.