Hemoglobins, encapsulated

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

Nakai, K. Usuba, A. Ohta, T. Kuwabara, M. Nakazato, Y. Motoki, R. Takahashi, T.A. Coronary vascular bed perfusion with a polyethylene glycol-modified hemoglobin-encapsulated liposome, neo red cell, in rats. Artif. 

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. 

C. Zhao, L. Wan, Q. Wang, S. Liu, and K. Jiao, Highly sensitive and selective uric acid biosensor based on direct electron transfer of hemoglobin-encapsulated chitosan-modified glassy carbon electrode. Anal. Sci., 25 (8), 1013-1017,2009. 

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. 

Huguet ML, Groboillot A, Neufeld RJ, Poncelet D, Dellacherie E. (1994). Hemoglobin encapsulation in chitosan/calcium alginate beads. 

Other biomedical and biological appHcations of mictocapsules continue to be developed. For example, the encapsulation of enzymes continues to attract interest even though loss of enzyme activity due to harshness of the encapsulation protocols used has been a persistent problem (59). The use of mictocapsules in antibody hormone immunoassays has been reviewed (60). The encapsulation of hemoglobin as a ted blood substitute has received much attention because of AIDS and blood transfusions (61). 

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... 

Several enzymes have been immobilized in sol-gel matrices effectively and employed in diverse applications. Urease, catalase, and adenylic acid deaminase were first encapsulated in sol-gel matrices [72], The encapsulated urease and catalase retained partial activity but adenylic acid deaminase completely lost its activity. After three decades considerable attention has been paid again towards the bioencapsulation using sol-gel glasses. Braun et al. [73] successfully encapsulated alkaline phosphatase in silica gel, which retained its activity up to 2 months (30% of initial) with improved thermal stability. Further Shtelzer et al. [58] sequestered trypsin within a binary sol-gel-derived composite using TEOS and PEG. Ellerby et al. [74] entrapped other proteins such as cytochrome c and Mb in TEOS sol-gel. Later several proteins such as Mb [8], hemoglobin (Hb) [56], cyt c [55, 75], bacteriorhodopsin (bR) [76], lactate oxidase [77], alkaline phosphatase (AP) [78], GOD [51], HRP [79], urease [80], superoxide dismutase [8], tyrosinase [81], acetylcholinesterase [82], etc. have been immobilized into different sol-gel matrices. Hitherto some reports have described the various aspects of sol-gel entrapped biomolecules such as conformation [50, 60], dynamics [12, 83], accessibility [46], reaction kinetics [50, 54], activity [7, 84], and stability [1, 80],... 

Fig. 3.21. Retention rate of liposome-encapsulated hemoglobin as a function of the time elapsed after the reconstitution of the freeze dried LEH, with different trehalose concentrations as CPA. 1, no trehalose 2, 10 mM 3, 50 mM 4, 150 mM 5, 300 mM trehalose (Fig. 2 from [3.43]).

Liposome-Encapsulated Hemoglobin as an Artificial Oxygen Carrier... 

One approach to compartmentalize hemoglobin is to encapsulate hemoglobin in biodegradable polymer-PEG-polylactide (30). These nanocapsules have a diameter of 80-150 nm and contain superoxide dismutase, catalase, carbonic anhydrase, and other enzymes of Embden-Meyerhof pathway that are needed for long-term function of an oxygen carrier (31,32). The polylactide capsules are metabolized in vivo to water and carbon... 

Figure 1 Schematic illustration of liposome-encapsulated hemoglobin. Abbreviations-. PEG, polyethylene gylcol HB, hemoglobin.

Figure 3 Manufacturing scheme for liposome-encapsulated hemoglobin (LEH). Lipid phase is mixed with hemoglobin and the mixture is homogenized in an extruder or a microfluidizer. Unencapsulated hemoglobin is separated by filtration, before PEGylation is performed by postinsertion. The resulting PEG-LEH is converted into oxyhemoglobin form and concentrated to obtain final product. Abbreviation IXC, interaction chamber.

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