Lectins and bacterial invasion factors for controlling endo- and transcytosis of bioadhesive drug carrier systems

Lectins are hemagglutinating proteins, found in all taxonomic groups of the plant kingdom and able to accomplish specific binding to membrane bound sugar moieties located at the cell surface of epithelial cells. Bioadhesive properties of lectins were quantified by their specific binding to Caco-2 cell monolayers. The differences between bioadhesion and mucoadhesion were described and two distinctive classes of lectins with different ways of intracellular trafficking were found. The concept of bioinvasion is explained by the invasion mechanism of Yersinia pseudotuberculosis after oral uptake. Bioinvasion is a new tool for oral drug delivery by receptor mediated endocytosis. Invasin, a 103 kD surface protein of Yersinia, was produced by biotechnology and covalently attached to model particles. We showed that the uptake of particles by MDCK cells can be significantly enhanced by functionalisation with invasin. Caco-2 cells do not express the receptors for Invasin (alpha(5) beta(1) Integrins) and therefore are limited for such studies. (C) 1997 Elsevier Science B.V.