NRL has been conducting research on developing techniques for the synthesis of durable, rugged lipids. Lipids are naturally occurring substances that "self-organize" into double layers that make up membranes of living cells. Both naturally occurring and synthetic lipids can be chemically modified. As modified by NRL, these materials have the potential for being applied in new electronic materials, optical elements, acoustic sensors, biological hybrid detection systems, and oxygen and drug delivery to the body.
In 1985, synthetic red cells based on the concept of liposome-encapsulated hemoglobin (LEH) were developed at NRL as a potential blood surrogate. In principle, hemoglobin solutions were added to a mixture of dry phospholipids and cholesterol and the dispersion was extruded under high pressure through narrow channels. The resulting liposomes lacked the blood group antigens, theoretically rendering them "universally" acceptable for transfusions. The blood surrogate was also storable up to 10 times longer than regular blood. Work is underway at NRL to extend the storage lifetime of LEH by freeze-drying; to transfer LEH technology to industry for manufacturing; to establish manufacturing and quality control standards; and to study LEH's physiological effects. The red blood cell surrogate research is directed toward improved methods of combat casualty care. It is hoped that this development may also be used in domestic emergency trauma care as well as in surgical procedures requiring multiple transfusions.