A fluorescence method for the determination of the molecular weight cut-off of alginate-polylysine microcapsules.
Several applications of microcapsules for the encapsulation of living cells or macromolecules require well defined pore sizes. The molecular weight cut-off of alginate-polylysine microcapsules has been determined using a range of fluorescent labelled dextran molecules. The diffusion of the fluorescein isothiocyanate labelled (FITC)-dextrans into the microcapsules was followed by fluorescence and confocal laser scanning microscopy. The permeability of microcapsules for FITC-dextrans with a molecular weight of 4,700 daltons and the impermeability for FITC-dextrans with a molecular weight of 40,500 daltons was confirmed with both techniques. Determination of the molecular weight cut-off, using confocal laser scanning microscopy was more reliable and required a smaller sample than fluorescence measurements.
Vandenbossche
G M
GM
Laboratory of Pharmaceutical Technology, State University of Ghent, Belgium.
Van Oostveldt
P
P
Remon
J P
JP
D000464:Alginates / Q000032:analysis*; D002214:Capsules; D003911:Dextrans; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005453:Fluorescence; D005456:Fluorescent Dyes; D008970:Molecular Weight; D011107:Polylysine / Q000032:analysis*; D013861:Thiocyanates
D000464:Alginates; D002214:Capsules; D003911:Dextrans; D005452:Fluoresceins; D005456:Fluorescent Dyes; D013861:Thiocyanates; D011107:Polylysine; D016650:Fluorescein-5-isothiocyanate