A Study of Liposome-Type Artificial Red Blood Cells Stabilized with Carboxymethyl Chitin

Abstract

Liposome-type artificial red blood cells (ARBC) stabilized with carboxymethyl chitin containing human hemolysate were prepared by a two-step emulsification technique. Electron microscopic observations using various techniques revealed that the ARBC have a mean diameter of about 310 nm and a multilamellar structure. Oxygen binding abilities of the ARBC and human hemolysate were measured by the use of a Clark-type oxygen electrode. They exibited a striking similarity in the shape of oxygenation curve. Disintegration tests on the ARBC using the enzymes (lysozyme, chitinase and phospholipase C), that can digest the components of the ARBC membrane, suggested that the membrane has a structure in which the phospholipid layer is covered by a mesh of CH chitin molecules in an aqueous phase. The acute toxicity of the ARBC to male mice was examined and LD50 values of the ARBC for 2 ml of intravenous injection was evaluated to be 13.8 ml/kg by the Litchfield-Wilcoxon method. The effect of the injected ARBC suspensions on the weights of the organs (liver, spleen and kidneys) were investigated and the differences in organ weight between the injected groups and the control ones were evaluated by a t-test.