Vesicles hemoglobin encapsulation

Satoh T, Kobayashi K, Sekiguchi S, et al. Characteristics of artificial red cells. Hemoglobin encapsulated in poly-lipid vesicles. ASAIO J 1992 38 M580. 

Sakai, H. Tsai, A.G. Intaglietta, M. Tsuchida, E. Hemoglobin encapsulation with polyethylene glycol-modified and unmodified vesicles systemic and microvascular hemodynamics at 80% blood substitution. In Advances in Blood Substitutes Industrial Opportunities and Medical Challenges Winslow, R.M., Vandegriff, K.D., Intaglietta, M., Eds. Birkhauser Boston, 1997 151-166. 

Sakai H, Okuda N, Sato A et al (2010) Hemoglobin encapsulation in vesicles retards NO and CO binding and O2 release when perfused through narrow gas-permeable tubes. Am J Physiol Heart Circ Physiol 298 H956-H965. 

The Jing group investigated their poly(L-lysine)-6-poly(L-phenylalanine) vesicles for the development of synthetic blood, since PEG-lipid vesicles were previously used to encapsulate hemoglobin to protect it from oxidation and to increase circulation time. They extended this concept and demonstrated that functional hemoglobin could be encapsulated into their vesicles. The same polypeptide material was also used to complex DNA, which caused the vesicles to lose their... 

Vandegriff KD, Wallach DF, Winslow RM. Encapsulation of hemoglobin in non-phospholipid vesicles. Artif Cells Blood Substit Immobil Biotechnol 1994 22 849. 

Gaber BP, Yager P, Sheridan JP, et al. Encapsulation of hemoglobin in phospholipid vesicles. FEBS Lett 1983 153 285. 

Takeoka S, Sakai H, Kose T, et al. Methemoglobin formation in hemoglobin vesicles and reduction by encapsulated thiols. Bioconjug Chem 1997 8 539. 

In another example, a photo-CTOss-linkable diblock PEO-h-P(DEA-j-CMA) copolymer based vesicles, encapsulating glucose oxidase (GOx) and hemoglobin, represents a pH-iesponsive nanoreactor in which a cross-linked coumarin-rich matrix contributes to the stability of the system, while cou-marin-poor patches fuuctiou as pH-triggered tuuuels [63]. 

The protein trapping efficiencies of the MLV and LUV systems were determined. Figure 28.3 shows the hemoglobin elution profiles for the LUV system and the buffer solution without vesicles. The profiles indicate that hemoglobin molecules were encapsulated in the LUV system. In addition, free hemoglobin could be separated from the vesicles because the absorbance of fraction 5, indicating protein trapped in the vesicles increased, whereas that of fraction 8, indicating free protein, decreased. Similar results were obtained with cytochrome c and lipase. 

Sakai H, Sato A, Masuda K et al (2008) Encapsulation of concentrated hemoglobin solution in phospholipid vesicles retards the reaction with NO, but not CO, by intracellular diffusion barrier. J Biol Chem 283 1508-1517. 

The composition of the encapsulating membrane is a combination of saturated phospholipids and cholesterol. The principal design feature of these constructs is the encapsulation ratio, that is, the ratio between the amount of hemoglobin contained versus the quantity of membrane used. One of the lowest ratios attained is 1.6 for the material developed by Tsuchida and coworkers [68] and similar results have been reported by Phillips and coworkers [5]. Another design parameter is particle size. As a general rule, the half-life of liposomes in the circulation is inversely proportional to particle size, and liposomes of diameter >200 nm are rapidly eliminated by the reticuloendothelial system. Complement activation was one of the early problems observed with the use of liposomes that was mostly solved by attaching PEG to the liposome surface [81]. This also prevented RBC aggregation and improved the dispersion state of the suspension and stabilization of the vesicles. 

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