GALACTOSE-CONTAINING AMPHIPHILES PREPARED WITH A LIPOPHILIC RADICAL INITIATOR - ASSOCIATION PROCESSES BETWEEN LIPOSOMES TRIGGERED BY ENZYMATIC-REACTION

A galactose-containing monomer (2-(methacryloyloxy)ethyl beta-D-galact opyranoside; MEGal) was polymerized by using a lipophilic radical init iator. The amphiphile obtained formed a liposome by mixing with ns,tra ns-2,4-dioctadecadienoyl)phosphatidylcholine (DDPC), and the liposome obtained was physically stabilized by the polymerization of DDPC by UV irradiation. The enzymatic treatment of the galactose-containing lipo somes with galactose oxidase resulted in the formation of aldehyde gro ups on the liposome surface. By the subsequent mixing of the liposome suspension with the amino group-containing liposome suspension, a rapi d increase in turbidity was observed due to the formation of Schiff ba ses between the aldehyde groups and the amino groups at the interface of the liposomes. The rate of turbidity change strongly depended on th e degree of polymerization of MEGal, the surface densities of galactos e and amino groups on the liposome, the distance from the liposome sur face to amino end groups, and the flexibility and deformability of the liposomes.