Toxicity of Liposomes Containing Low Mol% of Dienoyl Phosphocholine to Blood: Use of Carboxymethyl Chitin to Reduce Toxicity

Abstract

Toxic effects of liposomes composed of the synthetic lipid, 1, 2-bis (octadeca-2, 4-dicnoyl)-sn-glycero-3-phosphocholine (C₁₈DENPC) and cholesterol (Cho) were studied. In the present work, we have explored, 1) fusion between C₁₈DENPC/Choliposomes and erythrocyte ghost (EG) membranes with resonance energy transfer assay, 2) hemolysis induced by C₁₈DENPC/Choliposomes, and 3) turbidity changes in native plasma on contact with C₁₈DENPC/Cho-liposomes, in the presence or absence of carboxymethyl chitin (CM-chitin). In the absence of CM-chitin, extents of fusion, hemolysis and turbidity changes in native plasma increased with the decrease in C₁₈DENPC content. In the presnce of CM-chitin at a concentration of 10^-3 or 10^-2% (w/v), fusion of C₁₈DENPC/Cho-liposome with EG was inhibited. Extents of hemolysis and turbidity changes in native plasma induced by C₁₈DENPC/Cho-liposomes were reduced depending upon CM-chitin concentration.