Hemoglobin niosomes. I. Preparation, functional and physico-chemical properties, and stability

Hemoglobin niosomes. I, Preparation, functional and physical properties and stability. Hemoglobin niosomes (non ionic liposomes) obtained from L'Oréal synthetic lipids by solvents vaporization appear as unilamellar spherical red vesicles, isolated from each other and with heterogeneous size (0.5 to 4 microns). Their suspensions show a visible spectra superimposable to that of free hemoglobin which is incorporated at a rate of 0.3 to 0.5 g per lipid gram. Vesicles are permeable to oxygen and the hemoglobin dissociation curve can be modified similarly to non-encapsulated hemoglobin. Niosomes appear physically stable while hemoglobin undergoes a progressive oxidation to methemoglobin reaching 30% after 5 months at 4 degrees C. Even in the absence of dicetylphosphate (DCP), niosomes possess a negative charge confering to them an electrophoretic mobility. 5% DCP allows to obtain a zeta potential near to that of erythrocytes. The niosomes suspensions are more viscous than red blood cells but their rheological behavior is similar and the vesicles may have some deformability.