Gastrointestinal transit and mucoadhesion of colloidal suspensions of Lycopersicon esculentum L. and Lotus tetragonolobus lectin-PLA microsphere conjugates in rats.
OBJECTIVE
To investigate in vivo the fate and the behavior of lectin-particle conjugates after oral administration.


METHODS
Two plant lectins were selected, namely Lycopersicon esculentum L. and Lotus tetragonolobus lectins, which have been reported to be specific for oligomers of N-acetyl-D-glucosamine and L-fucose, respectively, and conjugated to small poly(lactide) microspheres. Their intestinal transit was investigated in detail using radiolabeled particles. The transport and the distribution of the particles along the intestine, as well as their interactions with the intestinal mucosa, were determined after oral administration in rat.


RESULTS
The overall transit of the particles was shown to be strongly delayed when the microspheres were conjugated to the lectins, mainly due to the gastric retention of the particles. A significant fraction of the conjugates adhered to the gastric and intestinal mucosae. No significant differences were observed after a preliminary incubation of lectin-microsphere conjugates with specific sugars.


CONCLUSIONS
Although specific interactions could not be excluded, especially in the stomach, it was likely that adhesion was predominantly due to nonspecific interactions. These results could be attributed both to unfavorable physicochemical characteristics of the conjugates and to premature adsorption of soluble mucin glycoproteins, preventing any further specific adhesion.
Montisci
M J
MJ
Laboratoire de Pharmacotechnie et Biopharmacie, UMR 8612, Faculté de Pharmacie, Université Paris-Sud, Châtenay-Malaby, France.
Dembri
A
A
Giovannuci
G
G
Chacun
H
H
Duchêne
D
D
Ponchel
G
G
D000269:Adhesives / Q000493:pharmacokinetics; D000818:Animals; D001672:Biocompatible Materials / Q000493:pharmacokinetics*; D003102:Colloids; D005746:Gastric Emptying / Q000502:physiology; D005772:Gastrointestinal Transit / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism; D037102:Lectins / Q000493:pharmacokinetics*; D008297:Male; D008863:Microspheres; D037121:Plant Lectins; D011091:Polyesters / Q000493:pharmacokinetics*; D051381:Rats; D013535:Suspensions; D014018:Tissue Distribution
D000269:Adhesives; D001672:Biocompatible Materials; D003102:Colloids; D037102:Lectins; D037121:Plant Lectins; D011091:Polyesters; D013535:Suspensions; C027112:fucose-binding lectin; C034981:tomato lectin; C033616:poly(lactide)