Accession Number : ADA137703

Title :   Liposomal-Encapsulated Stroma-Free Hemoglobin as a Potential Blood Substitute.

Descriptive Note : Annual progress rept. Apr 79-Mar 80,

Corporate Author : CALIFORNIA UNIV SAN FRANCISCO

Personal Author(s) : Hunt,C A

PDF Url : ADA137703

Report Date : 02 Jan 1980

Pagination or Media Count : 18

Abstract : We have successfully applied a new technique of high-yield encapsulation for liposome encapsulation of stroma-free hemoglobin (SFH). The procedure results in encapsulation of approximately 20% of a given SFH solution. The resulting hemoglobin-containing liposomes (HCL) range in size from approximately 0.05 to 1.0 microns in diameter. There is little or no binding of hemoglobin to these liposomes. The oxygen binding properties of the HCL are equal to or better than a corresponding amount of SFH in buffer. At 20 or 4 C leakage of hemoglobin from the HCL is minimal over 72 hrs. The HCL can be easily centrifuged and resuspended without significant lysis. Mild sucrose gradients (3-6%) can be used to separate the denser, hemoglobin-rich liposomes, from the lighter, hemoglobin-poor liposomes. These HCL are less sensitive to osmatic shock than are RBC's. In vivo studies show that uptake of liposomes by the reticuloendothelial system (RES) is not the primary mechanism for blood clearance of liposomes; disposition of intravenously administered liposomes is the result of circulating instability, tissue binding and, finally, RES uptake. Further, each of these processes is saturable. Results show that the liposomes of interest can be made reproducibly.

Descriptors :   *Blood substitutes, *Hemoglobin, Encapsulation, Methodology, Oxygen, Toxicity, Separation

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE