Preparation of insulin-containing microcapsules by a layer-by-layer deposition of concanavalin A and glycogen.
The sugar sensitive microcapsules were prepared by a layer-by-layer deposition of concanavalin A (Con A) and glycogen on a calcium carbonate particle containing fluorescein-labeled insulin (F-insulin). The Con A/glycogen multilayer capsules were formed through sugar-lectin interactions by using inner and outer poly(ethyleneimine)/poly(vinyl sulfate) multilayers as supports, while without the supports the microcapsules could not be formed. Fluorescent microscope observations revealed that the capsules thus prepared are spherical in shape with 3-10 microm diameter. The microcapsules released encapsulated F-insulin upon addition of sugars. This is because the added sugars replace glycogen in the binding site of Con A, resulting in the enhanced permeability of the microcapsules to insulin.
Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
Katsuhiko
K
Sato
Daisuke
D
Kodama
Yoshihiro
Y
Endo
Jun-ichi
J
Anzai
D002214:Capsules / Q000737:chemistry*; D003208:Concanavalin A / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods; D006003:Glycogen / Q000737:chemistry*; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry*; D008422:Materials Testing
D002214:Capsules; D004337:Drug Carriers; D007328:Insulin; D003208:Concanavalin A; D006003:Glycogen