Laser intensity dependence of femtosecond near-infrared optoinjection
Laser intensity dependence of femtosecond near-infrared optoinjection
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DOI：
10.1103/physreve.75.041903
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发表时间：
2007-04-01
影响因子：
2.4
通讯作者：
Wilke, Ingrid
中科院分区：
文献类型：
--
作者：
Peng, Cheng;Palazzo, Robert E.;Wilke, Ingrid
本文报道了飞秒近红外激光脉冲对牛主动脉内皮细胞（BAEC）瞬时膜透化的实验研究。研究了BAEC细胞膜透性随入射激光强度的变化。使用延时成像分析细胞的染料摄取速率。我们发现，膜透化发生的激光强度高于4.0 × 10（12）W/cm（2）。对于高于3.3 × 10（13）W/cm（2）的激光强度，细胞崩解。在这两个极限内，染料吸收率随激光强度的增加而呈几何级数增加。通过考虑激光焦斑上的高斯强度分布来解释这种函数依赖性。细胞膜透化是通过激光焦点内等离子体的产生来解释的。对染料摄取、孔特征和激光强度之间的关系的物理理解允许通过控制孔特征来控制递送到细胞中的分子的浓度。
We report an experimental study on transient membrane permeabilization of single living bovine aortic endothelial cells (BAEC) by tightly focused femtosecond near-infrared laser pulses. The membrane permeabilization of the BAEC cells was studied as a function of the incident laser intensity. The rate of dye uptake by the cells was analyzed using time-lapse imaging. We found that membrane permeabilization occurs for laser intensities higher than 4.0 x 10(12) W/cm(2). For laser intensity above 3.3 x 10(13) W/cm(2) the cell disintegrates. Within these two limits the rate of dye uptake increases logarithmically with increasing laser intensity. This functional dependence is explained by considering the Gaussian intensity distribution across the laser focal spot. Cell membrane permeabilization is explained by the creation of a plasma within the laser focal spot. The physical understanding of the relationship between dye uptake, pore characteristics, and laser intensity allows control of the concentrations of molecules delivered into cells through the control of pore characteristics.