Poloxamine 1107 sealing of radiopermeabilized erythrocyte membranes

Abstract

Purpose : Lipid peroxidation-mediated permeabilization of cell membranes following intense ionizing irradiation is well documented. This form of membrane radiopermeabilization leads to rapid exhaustion of cellular high-energy compounds, resulting in the acute onset of cellular necrosis. Strategies to reverse the process of necrosis and preserve cell viability require membrane sealing. This report documents the relative efficacy of Poloxamine 1107, a non-ionic surfactant, compared with other polymers, in sealing radiopermeabilized cell membranes. Materials and methods : Isolated erythrocytes were exposedto 600Gy 60Co irradiation at a dose rate of 1.3Gy/s. Different polymer compounds were added 10min later to the irradiated cell suspensions. At 2h later the haemoglobin content in the supernatants was determined spectrophotometrically. Results : Compared with the non-treated irradiated control, Poloxamine 1107 significantly reduced the leakage of haemoglobin from irradiated erythrocytes. Poloxamer 188 and dextran at equal concentrations had no significant reverse effect on the irradiation-mediated increased membrane permeability. The amount of haemoglobin released from irradiated erythrocytes was inversely related to the Poloxamine 1107 concentration. Conclusions : This study demonstrates the capability of Poloxamine 1107 to seal radiopermeabilized cell membranes. Thus, surfactants such as Poloxamine 1107 might be useful as a therapeutic agent in the treatment of high-dose radiation injuries since cellular necrosis due to metabolic exhaustion following radiopermeabilization of their membranes might be prevented.