Immobilization of prostaglandin PGF2 alpha on poly(vinyl alcohol)

Prostaglandin PGF2 alpha was immobilized onto a poly(vinyl alcohol) hydrogel (PVA) by reaction of a PGF2 alpha-polylysine adduct with glutaraldehyde. The PGF2 alpha-polylysine adduct was prepared by carbodiimide activation of the carboxyl group of PGF2 alpha followed by coupling to the lysine. The adduct was separated from the unreacted PGF2 alpha by dialysis and the purified product was found to contain congruent to 44 mol of PGF2 alpha/mol of adduct involving congruent to 40% of the amines of the polylysine. The adduct was bound to PVA by reacting with an excess of glutaraldehyde at 0 degrees C, followed by cross-linking of the PVA to a gel at 35-37 degrees C. The PGF2 alpha of the adduct was found to retain congruent to 40% of its biological activity on a molar basis in a smooth muscle cell contraction assay, but its activity immobilized to PVA was not determined. Spectroscopically, infrared nuclear magnetic resonance (IR/NMR), the PGF2 alpha appeared identical to the native molecule, except for the amide bond at its carboxylic acid, suggesting that the reactions were very gentle and that other biomolecules could be incorporated into the gel without loss of activity.