LECTINS FOR DRUG-DELIVERY WITHIN THE ORAL CAVITY - INVESTIGATION OF LECTIN-BINDING TO ORAL-MUCOSA

The aim of this study was to identify receptors present on the buccal mucosa in order to select appropriate lectins that will allow the rete ntion of a dosage form within the oral cavity, Studies using human buc cal cells, the avidin-biolin-complex/diaminobenzidine method for ident ifying lectin binding and a microdensitometer to allow a semi -quanita tive analysis of stain intensity, showed a wide diversity of lectin re ceptors. Kinetic studies of lectin binding to buccal cells revealed si gnificant binding after 20 a, particularly for lectins from Pisum sati vum and Arachis hypogaea. A significant reduction in lectin binding wa s observed after exposing buccal cells to a series of lectin solutions pre-treated with a large excess of secretor or non-secretor saliva. H owever when bound to the bucca! cells, there was little displacement o f lectins on exposure to either saliva types. Further studies on rat o ral tissue suggested that the lectins appeared to bind to varying degr ees on whole oral epithelial surfaces although differences in binding between this and the human buccal cell model were evident. It was conc luded that a wide range of possible target receptors for lectins are p resent on rat oral epithelium and human buccal cells. Lectin binding t o these receptors can be affected by the exposure rime and the presenc e of saliva.