Studies on the uptake of tomato lectin nanoparticles in everted gut sacs

Tomato lectin (TL) is a bioadhesive glycoprotein that has been shown to bin d selectively to the small intestine epithelium. When bound to polystyrene microspheres, intestinal uptake occurs not only through the gut associated lymphoid tissue (GALT) but also through normal enterocytes. In this study, the everted gut sac model was used to compare the rates and quantities of i ntestinal uptake of tomato lectin and that of TL coupled to microspheres. U sing bovine serum albumin (BSA) and BSA coupled to microspheres as comparat ors. Uptake is time and concentration dependent. Transfer of TL from the lu men to the serosa was 3.9 ng/mg per h whereas that of BSA was 0.5 ng/mg per h. Hence uptake of tomato lectin was 7-fold higher than BSA. The rate of u ptake of TL coupled microspheres was 41.5 ng/mg per h, which was 4-fold hig her than microspheres coupled to BSA (11.8 ng/mg per h). The uptake of TL c onjugated microspheres was shown to be inhibited by N-acetyl-D-glucosamine tetramer [GlcNac](4). (C) 1999 Elsevier Science B.V. All rights reserved.