H2O2-Diffusion Through Liposomes

The toxicity of H2O2 suggests that it readily diffuses through cell membranes. The present paper demonstrates via a chromogenic peroxidase reaction that H2O2 can cross the lipid bilayer membrane without affecting the cell wall's integrity. In this demonstration, the chromogen ABTS was encapsulated with horseradish peroxidase into ovolecithin multilamellar liposomes. Upon the addition of dilute H2O2, the color was generated exclusively within the intact liposomes. Related results were observed with the AAP/DHBS chromogenic couple; however, this system is complicated by the small holes created by the phenol DHBS in the liposomal wall.