Sliozberg Yelena, Chantawansri Tanya
TKC Global at U.S. Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, Maryland 21005-5069, USA.
U.S. Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, Maryland 21005-5069, USA.
J Chem Phys. 2014 Nov 14;141(18):184904. doi: 10.1063/1.4901130.
Traumatic Brain Injury is a major health issue that is hard to diagnose since it often occurs without signs of external injuries. While it is well known that exposure of biological cells to shock waves causes damage to the cell membrane, it is currently unknown by which mechanisms damage is caused, and how it depends on physical parameters such as shock wave velocity, shock pulse duration, or shock pulse shape. In this computational study, we use a coarse-grained model of the lipid vesicle as a generic model of a cell membrane to elucidate the general principles of the cellular damage induced by the shock wave direct passage through the cranium. Results indicate that the extent of the liposome compression does not strongly depend on the pressure pulse and that liposome extension is very sensitive to the change in the negative pressure phase. The structural integrity of the vesicle is altered as pores form in the lipid membrane at overall pressure impulses generated by supersonic shock waves, which are greater than 5 Pa·s at single or repetitive exposure. Consequently, these permeability changes may lead to changes in the influx of sodium, potassium, and calcium ions.
创伤性脑损伤是一个重大的健康问题，由于其常常在没有外部损伤迹象的情况下发生，因此很难诊断。虽然众所周知，生物细胞暴露于冲击波会导致细胞膜损伤，但目前尚不清楚损伤是由何种机制引起的，以及它如何依赖于诸如冲击波速度、冲击脉冲持续时间或冲击脉冲形状等物理参数。在这项计算研究中，我们使用脂质囊泡的粗粒度模型作为细胞膜的通用模型，以阐明冲击波直接穿过颅骨所引起的细胞损伤的一般原理。结果表明，脂质体压缩程度并不强烈依赖于压力脉冲，并且脂质体伸展对负压阶段的变化非常敏感。在由超音速冲击波产生的总压力脉冲作用下，脂质膜上形成孔隙，囊泡的结构完整性发生改变，单次或重复暴露时，总压力脉冲大于5 Pa·s。因此，这些通透性变化可能导致钠、钾和钙离子内流的改变。
