Liposome-encapsulated hemoglobin stability

Ligler FS, Stratton, LP, Rudolph AS. Liposome encapsulated hemoglobin stabilization, encapsulation, and storage. Prog Clin Biol Res 1989 319 435. 

Cliff RO, Ligler E, Goins B, et al. Liposome encapsulated hemoglobin longterm storage stability and in vivo characterization. Biomater Artif Cells Immo-bil Biotechnol 1992 20 619. 

Sherwood RL, McCormick DL, Zheng S, et al. Influence of steric stabilization of liposome-encapsulated hemoglobin on Listeria monocytogenes host defense. Artif Cells Blood Substit Immobil Biotechnol 1995 23 665. 

Szebeni J, Di lorio EE, Hauser H, et al. Encapsulation of hemoglobin in phospholipid liposomes characterization and stability. Biochemistry 1985 24 2827. 

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. 

---