In vitro bioadhesion of carbohydrate-containing N-(2-hydroxypropyl) methacrylamide copolymers to the GI tract of guinea pigs

Abstract N -(2-Hydroxypropyl)methacrylamide (HPMA) copolymers with different content of pendant saccharide moieties (galactosamine, fucosylamine, glucosamine, mannosamine) were synthesized and their bioadhesive properties to the gastrointestinal (GI) tract of female adult guinea pigs have been studied in vitro. Radioiodinated HPMA copolymers were incubated with everted sacs or enterocytes isolated from guinea pig small intestine and colon. The results obtained with everted sacs clearly indicated preferential binding of fucosylamine containing HPMA copolymers to the colonic mucus. The extent of binding increased with increasing fucosylamine content in the copolymers and with the time of incubation, and decreased with increasing molecular weight of the copolymers. The binding was partially inhibited by the presence of free fucose or glucose in the incubation medium. Fucosylamine containing HPMA copolymers also bind to isolated enterocytes and the extent of binding increases with increased fucosylamine content of HPMA copolymers. Contrary to the results obtained on everted sacs, there was no difference in binding to enterocytes isolated either from the small intestine or colon. The results obtained indicate the presence of lectine-like structures in the guinea pig GI tract.