Cationic cholesterol-containing amphiphiles, cholesteryl-oxycarbonyl-methyl 8-(acryloyloxy) 3,6-oxaoctyl dimethyl ammonium bromide (CHODAMA-oxy-3), cholesteryl-oxycarbonyl-methyl 5-(acryloyloxy) 3-oxapentyl dimethyl ammonium bromide (CHODAMA-oxy-2) and cholesteryl 11-(2-hydroxy N,N-dimethyl ammonium) 3,6,9-oxaundecanoate (CHODAUN) were synthesized and the properties of these amphiphile in aqueous solution were investigated with electron microscope, viscometer and differential scanning calorimeter.
The morphology of monomeric CHODAMA-oxy-3 in aqueous solution was thread-like structure (width:95A) but the thread-like structure was ruptured and aggregated form appeared during polymerization. When the monomeric CHODAMA-oxy-3 solution was maintained at room temperature for one month, the thread-like structure changed to vesicles completely (diameter: 600-1000A). Monomeric CHODAMA-oxy-2 and its polymers in aqueous solution formed all vesicles. In the case of CHODAUN, when the CHODAUN solution was sonicated at 30 C for five minutes, diverse morphology were found such as thread-like and tubular structures. But the thread-like and tubular structures transformed to vesicles when the solution was heated at 70℃ for twelve hours.
Viscosity measurements indicated that monomeric solution of CHODAMA-oxy-3 and CHODAMA-oxy-2 were more viscous than water. But the viscosities of polymeric solution of CHODAMA-oxy-3 and CHODAMA-oxy-2 were almost equal to that of water.
Phase transition temperatures were observed at 34℃ for monomeric CHODAMA-oxy-2 and 73℃ for monomeric CHODAMA-oxy-3 by differential scanning calorimeter.
