Binding and uptake of wheat germ agglutinin-grafted PLGA-nanospheres by caco-2 monolayers.
OBJECTIVE
The Caco-2 association of lectin-grafted PLGA-nanospheres was investigated compared to plain and BSA-coated spheres.


METHODS
Nanospheres made from fluorescent-labeled PLGA were coated with wheat germ agglutinin (WGA) or BSA and incubated with Caco-2 monolayers varying the concentration of nanospheres, the time, and the temperature. The tests were performed in a static horizontal as well as an aerated vertical setup to find out the system most appropriate for estimation of bioadhesion.


RESULTS
Due to bioadhesive effects, WGA-modified particles exhibited highest association to the cells as compared to plain and BSA-coated ones. The amount of associated spheres increased with time and concentration of the nanosphere suspension. Whereas the binding of lectin-coated spheres was independent from energy, their uptake was energy consuming as opposed to BSA and plain nanospheres, which exhibited nonspecific, energy independent binding and uptake. Although more particles were associated with the monolayer in the horizontal setup than in the vertical system, the vertical system reflects true bioadhesion due to circulation of the spheres which inhibits the influence of sedimentation.


CONCLUSIONS
Immobilization of WGA considerably enhances the binding as well as the uptake of PLGA-nanospheres by Caco-2 monolayers. For bioadhesion studies, the vertical setup is recommended instead of the horizontal setup.
Weissenboeck
Andrea
A
Institute of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
Bogner
Elisabeth
E
Wirth
Michael
M
Gabor
Franz
F
D000268:Adhesiveness; D001273:Atmosphere Exposure Chambers; D018938:Caco-2 Cells; D002103:Cadaverine / Q000378:metabolism; D002241:Carbohydrates; D002626:Chemistry, Pharmaceutical; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism*; D037102:Lectins; D018613:Microscopy, Confocal; D008863:Microspheres; D011100:Polyglycolic Acid / Q000737:chemistry / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013499:Surface Properties; D014909:Wheat Germ Agglutinins / Q000737:chemistry / Q000378:metabolism*
D002241:Carbohydrates; D005452:Fluoresceins; D005456:Fluorescent Dyes; D037102:Lectins; D011108:Polymers; D014909:Wheat Germ Agglutinins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D012710:Serum Albumin, Bovine; D019344:Lactic Acid; D002103:Cadaverine