Liposome-encapsulated hemoglobin: an oxygen-carrying fluid

Area of Science:

• Biomedical Engineering
• Materials Science
• Hematology

Background:

• Lipid-encapsulated hemoglobin (LEH) has evolved from early concepts to a functional oxygen-carrying fluid.
• Significant advancements have been made in LEH formulation, fabrication technology, and large-scale production.
• Challenges remain in standardization of quality control methods and proving in vivo safety.

Purpose of the Study:

• To review the evolution and current status of lipid-encapsulated hemoglobin (LEH) as an oxygen carrier.
• To identify areas for further improvement in LEH production, characterization, and application.
• To discuss strategies for enhancing LEH biocompatibility and long-term preservation.

Main Methods:

• Evolution of outer shell composition from synthetic materials to lipid blends (egg-lecithin, distearoyl-phosphatidylcholine).
• Advancement in fabrication technology from milliliter to multi-liter quantities using high-pressure extrusion.
• Inclusion of carbohydrate moieties, such as gangliosides, to improve liposome surface biocompatibility.

Main Results:

• LEH demonstrates oxygen-carrying capacity sufficient to sustain life in vivo.
• Established circulation half-life of 16-20 hours in vivo.
• Inclusion of gangliosides has shown potential for increased circulation times and reduced RES system impact.

Conclusions:

• LEH has progressed significantly in production and oxygen transport capabilities.
• Further research is crucial for standardization of quality control, safety validation, and exploring lyophilized formulations.
• Enhancing biocompatibility through surface modification, like ganglioside incorporation, is a promising avenue for improved LEH performance.