Synthesis of molecularly imprinted polymer of beta-cyclodextrin for the efficient recognition of cholesterol

Polymeric receptors for cholesterol were synthesized by crosslinking beta-c yclodextrin (beta-CyD) with hexamethylene diisocyanate or toluene 2,4-diiso cyanate in dimethyl sulfoxide (DMSO) in the presence of cholesterol as the template. Non-imprinted beta-CyD polymers were much poorer in the cholester ol adsorption. When beta-CyD was cross-linked by epichlorohydrin in aqueous alkaline solutions (even in the presence of cholesterol), the cholesterol adsorbing activity was nil. Use of DMSO as the cross-linking solvent is nec essary for the imprinting, since beta-CyD molecules form inclusion complexe s with cholesterol in this solvent and thus their mutual conformation in th e polymer is regulated appropriately for cholesterol binding. The adsorbed cholesterol was completely removed from the polymers by treating the adduct s with ethanol, indicating a strong potential for practical applications. ( C) 1998 Published by Elsevier Science Limited. All rights reserved.