Abstract
The effects of carboxyacyl phosphatidylethanolamine derivatives (CA-PE) on the physicochemical properties of liposomes were examined from standpoints of zeta-potential, agglutination, phase transition temperature, microviscosity and micropolarity. Absolute zeta-potential of liposomes containing Succinyl-PE or Glutaryl-PE exceeded that of those containing Dodecanyl-PE. The addition of Succinyl-PE or Glutaryl-PE to liposomes resulted in even less microviscosity close to membrane surfaces of liposomes, compared to Dodecanyl-PE. The exposure of hydrophilic moiety of Succinyl-PE or Glutaryl-PE on liposome surfaces and orientation of carboxyacyl groups of Dodecanyl-PE differing from that of other CA-PE may be explanation for these findings. Avidin-biotin reaction-induced agglutination of liposomes containing Succinyl-PE or Glutaryl-PE was found to be reduced, possibly due to a steric barrier of exposed hydrophilic groups of Succinyl-PE or Glutaryl-PE on liposome surfaces.
