Department of Electronics and Information Systems Engineering, Faculty of Engineering, Osaka Institute of Technology, Osaka, 535-8585, Japan.
Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
Sci Rep. 2022 Nov 8;12(1):19001. doi: 10.1038/s41598-022-23733-5.
High intensity near infrared femtosecond laser is a promising tool for three-dimensional processing of biological materials. During the processing of cells and tissues, long lasting gas bubbles randomly appeared around the laser focal point, however physicochemical and mechanical effects of the gas bubbles has not been emphasized. This paper presents characteristic behaviors of the gas bubbles and their contact effects on cell viability. High-speed imaging of the gas bubble formation with various additives in physiological medium confirms that the gas bubble consists of dissolved air, and amphipathic proteins stabilize the bubble surface. This surface protective layer inhibits interactions of gas bubbles and cell membranes. Consequently, the gas bubble contact does not cause critical effects on cell viability. On the other hands, burst of gas bubbles stimulated by an impact of femtosecond laser induced cavitation can lead to liquid jet flow that might cause serious mechanical damages on cells. These results provide insights for the parameter of biological tissue processing with intense fs laser pulses.
高强度近红外飞秒激光是三维处理生物材料的一种很有前途的工具。在处理细胞和组织时，激光焦点周围会随机出现长时间存在的气泡，但气泡的物理化学和力学效应尚未得到重视。本文介绍了气泡的特征行为及其对细胞活力的接触效应。在生理介质中添加各种添加剂的高速成象证实了气泡由溶解的空气组成，两亲性蛋白质稳定了气泡表面。这一表面保护层抑制了气泡和细胞膜之间的相互作用。因此，气泡的接触不会对细胞活力产生关键影响。另一方面，飞秒激光诱导空化冲击引发的气泡爆裂会产生液流射流，可能对细胞造成严重的机械损伤。这些结果为利用强飞秒激光脉冲处理生物组织的参数提供了参考。
