Accession Number : ADA266505


Title :   Encapsulation of Hemoglobin in Non-Phospholipid Vesicles


Corporate Author : LETTERMAN ARMY INST OF RESEARCH PRESIDIO OF SAN FRANCISCO CA DIV OF BLOOD RESEARCH


Personal Author(s) : Vandegriff, K D ; Wallach, D F ; Winslow, R M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266505.pdf


Report Date : Jan 1993


Pagination or Media Count : 6


Abstract : The efficiency of encapsulating hemoglobin in non-phospholipid liposomes by rapidly mixing hemoglobin with lipids heated above their solid- liquid phase transition temperature was examined. Human hemoglobin was mixed at 55-60 deg C with a lipid solution containing polyoxyethylene-2 cetyl ether and cholesterol (molar ratio, 3:1) at 60-65 deg C. Repeated mixing was carried out through a high-shear orifice, followed by rapid cooling and additional mixing. Lipid vesicles were heterogeneous in size, with diameters from approx. 300 nm to 10 micrometers. The non-encapsulated aqueous phase was removed by centrifugation, and total hemoglobin was determined spectrophotometrically. Encapsulation efficiency was calculated as the percentage of hemoglobin associated with the liposome phase (i.e., encapsulated) as a function of hemoglobin concentration and the aqueous:lipid hydration ratio. Hemoglobin concentrations were varied from 1 to 10 mM (in heme). Aqueous:lipid ratios of 8:1 and 4:1 were tested. Percent encapsulation varied from 13-30%, with the greatest efficiency, i.e., 30%, at a 4:1 hydration ratio of hemoglobin:lipid at 5.6 mM hemoglobin.


Descriptors :   *LIPOSOMES , *ENCAPSULATION , *HEMOGLOBIN , FUNCTIONS , DIAMETERS , RATIOS , TEMPERATURE , SOLIDS , PHASE , ETHERS , POLYOXYETHYLENE , HYDRATION , PHOSPHOLIPIDS , ORIFICES , SOLID PHASES , POLYETHERS , TRANSITIONS , MIXING , CHOLESTEROL , TRANSITION TEMPERATURE , COOLING , EFFICIENCY , HUMANS , PHASE TRANSFORMATIONS , LIPIDS


Subject Categories : Biochemistry


Distribution Statement : APPROVED FOR PUBLIC RELEASE