Oxygen solubility, rheology and hemodynamics of perfluorocarbon emulsion blood substitutes

Perfluorocarbon-based blood substitute emulsions have been under development for more than a quarter century. The first generation emulsions have provided confirmation that the physical principals of high gas solubility and low viscosity can effectively support organ and organism respiration and metabolism. Clinical trials led the US FDA in 1990 to be the first to approve a 20 w/v % perfluorocarbon emulsion for human use as coronary angioplasty adjuvant therapy. Hemodynamic responses to hemodilution with intravascular perfluorocarbon emulsions have varied with species and the mechanisms for adverse reactions are better understood now as second generation emulsions containing up to 100 w/v % perfluorocarbon are under development as blood substitutes, imaging agents, and for other therapeutic applications. This report describes the evolution of perfluorocarbon emulsions as blood substitutes by emphasizing oxygen solubility, rheology and hemodynamic aspects of the emulsions as they have been applied in experimental laboratory animal and human clinical settings.