The present work is focused on investigating the behavior of controlled drug release
poly(N-isopropylacrylamide) (PNIPA)
hydrogels in the presence of
beta-cyclodextrin (beta-CD). For this purpose, three types of NIPA
hydrogels with beta-CD moieties were synthesized with different architectures according to our previous studies. An anti-
cancer drug (
chlorambucil, CLB), which can form an inclusion complex with beta-CD, was selected for loading and in vitro release studies. The
drug was loaded into
hydrogels via a swelling method. DSC was used to study the interactions between the CLB molecules and the
polymers. The results indicate that the CLB-
polymer interactions are at the molecular level. Loading CLB into these
polymers can result in an evident decrease in the glass transition temperature (T(g)), and the variation of T(g) (DeltaT(g)) depends on the structures of the
polymers and their beta-CD content. The controlled release experiments show that the presence of beta-CD can markedly enhance CLB release from shrunken PNIPA
hydrogels and increase the ratio of CLB released in total
drug loading content. Release profile of CLB from
hydrogels 1a-c and 4 at pH 1.4 and 7.4, at 37 degrees C.