细胞的力学性质与生命体的功能和健康都是息息相关的,而原子力显微镜(atomic force microscope,AFM)是研究细胞力学性质最好的仪器之一。该文较为详细叙述了AFM力曲线测量原理,以及分析AFM实验数据的常用模型。作者用该文所提到的模型分析了肺癌细胞的弹性,结果显示在加载速率比较低的情况下,三种计算方法计算得到的结果没有显著差别,而在加载速率高于8μm/s时,结果则有显著差异。
细胞表面的力学性质会随着细胞所处环境的不同而发生改变,它的变化间接反映出胞内复杂的生理过程。原子力显微镜(atomic force microscope,AFM)能以高的灵敏度和分辨率检测活体细胞,通过利用赫兹模型分析力曲线可以获得细胞的弹性信息。本文简介了原子力显微镜的工作原理与工作模式,着重介绍利用AFM力曲线检测细胞弹性的方法及其在细胞运动、细胞骨架、细胞黏附、细胞病理等方面的应用成果,表明AFM已经成为细胞弹性研究中十分重要的显微技术。
Decellularization method based on trypsin-digestion is widely used to construct small diameter vascular grafts.However,this method will reduce the opening angle of the blood vessel and result in the reduction of residual stress.Residual stress reduced has an adverse effect on the compliance and permeability of small diameter vascular grafts.To improve the situation,acellular blood vessels were treated with glutaraldehyde and photooxidation crosslinking respectively,and the changes of opening angle,circumferential residual strain of native blood vessels,decellularized arteries and crosslinked blood vessels were measured by means of histological examination,scanning electron microscopy(SEM)and transmission electron microscopy(TEM)in this study.The opening angle of decellularized arteries significantly restored after photooxidation crosslinking(P紏0.0216),while that of glutaraldehyde crosslinking blood vessels reduced.The elastic fibers inside the blood vessels became densely rearranged after photooxidation crosslinking.The results of finite element simulation showed that the residual stress increased with the increase of opening angle.In this study,we found at the first time that photooxidation crosslinking method could significantly increase the residual stress of decellularized vessels,which provides biomechanical support for the development of new biomaterials of vascular grafts.
