Yield strength of human erythrocyte membranes to impulsive stretching.
Biophys J
; 105(4): 872-9, 2013 Aug 20.
Article
em En
| MEDLINE
| ID: mdl-23972839
ABSTRACT
Deformability while remaining viable is an important mechanical property of cells. Red blood cells (RBCs) deform considerably while flowing through small capillaries. The RBC membrane can withstand a finite strain, beyond which it ruptures. The classical yield areal strain of 2-4% for RBCs is generally accepted for a quasi-static strain. It has been noted previously that this threshold strain may be much larger with shorter exposure duration. Here we employ an impulse-like forcing to quantify this yield strain of RBC membranes. In the experiments, RBCs are stretched within tens of microseconds by a strong shear flow generated from a laser-induced cavitation bubble. The deformation of the cells in the strongly confined geometry is captured with a high-speed camera and viability is successively monitored with fluorescence microscopy. We find that the probability of cell survival is strongly dependent on the maximum strain. Above a critical areal strain of â¼40%, permanent membrane damage is observed for 50% of the cells. Interestingly, many of the cells do not rupture immediately and exhibit ghosting, but slowly obtain a round shape before they burst. This observation is explained with structural membrane damage leading to subnanometer-sized pores. The cells finally lyse from the colloidal osmotic pressure imbalance.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Deformação Eritrocítica
/
Membrana Eritrocítica
/
Fenômenos Mecânicos
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article