Influence of nanosilver on osmotic fragility responses of erythrocyte membrane following Na+/K+-ATPase blockade

Abstract

Background: The molecular mechanisms and overt effects of nanoparticle-induced changes in red blood cells (RBCs) structure and function across membrane cell lines remain unclear despite the increasing use and application in nanomedicine. The aim of this study was to assess the impact of nanosilver exposure on osmoregulation of red cell membrane fragility in digoxin-induced Na+-K+ATPase blockade in vitro.

Materials and Method: Samples from 50 subjects were obtained from consenting asymptomatic adults: male and female HbAA haemoglobin genotype. After separation and washing of erythrocytes, the samples were divided into three sets with each sample treated in duplicate with graded percentage concentrations of phosphate buffer solutions (0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, and 0.1). The second and third set of samples were incubated with 0.05ml of erythrocytes, 1 ml phosphate buffer saline and 1 ml nanosilver or digoxin of 25 mg/ml. Thereafter, the content of each test tube was incubated for 1 hour and 3 hours respectively. The absorbance was recorded after 30mins incubation for each set with standard spectrophotometer at 540 nm wavelength. Haemolysis in each tube was recorded and expressed as percentage of the absorbance in distilled water. The average values recorded were plotted against the different  concentrations used.

Results: Erythrocytes from the sample incubated with nanosilver had significantly increased osmotic lysis compared with the untreated cells in rate-depended manner (P<0.05). Similar pattern was observed with digoxin pre-incubated cells. The mean osmotic fragility (MOF) index of the untreated, nanosilver and digoxin pre-incubated cells was in the order: digoxin>nanosilver>untreated.

Conclusion: exposure of RBCs to nanosilver and in Na+/K+ATPase blockade may result in increased hemolytic effects by multifactorial cell membrane-mediated processes