Homogeneous Deformation of Native Erythrocytes During Long-Term Storage

Abstract

Purpose of the study — to evaluate biomechanical regularities of deep deformation of native erythrocytes’ membranes during long-term (up to 32 days) storage of erythrocyte suspension.Materials and methods. The method for addressing the said problem was atomic-force spectroscopy. The measured value was hHz comprizing the depth to which the probe immersion process was described by interaction with a homogeneous medium. Empirical and theoretical dependence of the interaction force F (nN) on the probe immersion depth h (nm) — F (h) were obtained. Bar charts of relative frequency density of Young’s modulus E were built.Results. Modulus E changed from 9.3±3.2 kPa — for 3 days of storage, to 22.7±8.7 kPa — for 32 days. Coefficients of skewness were 0.52±0.04 (for day 3) and 0.82±0.09 (for day 32 d), hHz value remaining constant.Conclusion. Progressively as erythrocyte suspension was stored, erythrocyte membranes to the depth of 700 nm deflected homogeneously in spite of 2.4-fold increase of Young’s modulus.

Keywords

• erythrocytes
• membrane stiffness
• deformation
• blood storage
• atomic-force spectroscopy