Matthews Benjamin D, Overby Darryl R, Alenghat Francis J, Karavitis John, Numaguchi Yasuchi, Allen Philip G, Ingber Donald E
Vascular Biology Program, Department of Pathology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Biochem Biophys Res Commun. 2004 Jan 16;313(3):758-64. doi: 10.1016/j.bbrc.2003.12.005.
A permanent magnetic microneedle was developed to apply tensional forces to integrin receptors via ligand-coated magnetic microbeads while optically analyzing the mechanical properties of individual focal adhesions. Force application (130 pN for 3 s) through activated beta1 integrins produced less bead displacement than when unligated integrins were stressed. This strengthening response differed markedly on a bead-by-bead basis, correlated directly with local focal adhesion assembly, and was similar when analyzed at 4 degrees C, indicating that it was due to passive material properties of the cell. Viscoelastic analysis clarified that recruitment of focal adhesion proteins increased the local elastic stiffness of the adhesion complex without changing its viscous behavior. These data indicate that individual focal adhesions exhibit distinct mechanical properties that depend upon local focal adhesion assembly, and that these local variations in micromechanics can be detected and analyzed within living cells using the permanent magnetic microneedle technique.
开发了一种永磁微针，通过配体包被的磁性微珠对整合素受体施加张力，同时光学分析单个粘着斑的力学性能。通过激活的β1整合素施加力（130皮牛，持续3秒）产生的微珠位移比未连接整合素受力时要小。这种强化反应在逐个微珠的基础上有显著差异，与局部粘着斑组装直接相关，并且在4℃分析时类似，表明这是由于细胞的被动材料特性所致。粘弹性分析表明，粘着斑蛋白的募集增加了粘着复合物的局部弹性刚度，而不改变其粘性行为。这些数据表明，单个粘着斑表现出取决于局部粘着斑组装的独特力学性能，并且使用永磁微针技术可以在活细胞内检测和分析这些微观力学的局部变化。
