Moutzouri Antonia G, Athanassiou George M
Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering and Aeronautics, University of Patras, 26504 Rio, Patras, Greece.
Biomed Res Int. 2014;2014:740726. doi: 10.1155/2014/740726. Epub 2014 May 29.
Cell adhesion on substrates is accompanied by significant changes in shape and cytoskeleton organization, which affect subsequent cellular and tissue responses, determining the long-term success of an implant. Alterations in osteoblast stiffness upon adhesion on orthopaedic implants with different surface chemical composition and topography are, thus, of central interest in the field of bone implant research. This work aimed to study the mechanical response of osteoblasts upon adhesion on chitosan-coated glass surfaces and to investigate possible correlations with the level of adhesion, spreading, and cytoskeleton reorganization. Using the micropipette aspiration technique, the osteoblast elastic modulus was found higher on chitosan-coated than on uncoated control substrates, and it was found to increase in the course of spreading for both substrates. The cell-surface contact area was measured throughout several time points of adhesion to quantify cell spreading kinetics. Significant differences were found between chitosan and control surfaces regarding the response of cell spreading, while both groups displayed a sigmoidal kinetical behavior with an initially elevated spreading rate which stabilizes in the second hour of attachment. Actin filament structural changes were confirmed after observation with confocal microscope. Biomaterial surface modification can enhance osteoblast mechanical response and induce favorable structural organization for the implant integration.
细胞在基质上的黏附伴随着形状和细胞骨架组织的显著变化，这些变化会影响随后的细胞和组织反应，决定植入物的长期成功。因此，成骨细胞在具有不同表面化学成分和形貌的骨科植入物上黏附时的硬度变化，是骨植入物研究领域的核心关注点。这项工作旨在研究成骨细胞在壳聚糖包被的玻璃表面上黏附时的力学反应，并研究其与黏附、铺展和细胞骨架重组水平之间可能存在的相关性。使用微量移液器抽吸技术发现，成骨细胞在壳聚糖包被的基质上的弹性模量高于未包被的对照基质，并且在两种基质上，弹性模量都在铺展过程中增加。在多个黏附时间点测量细胞-表面接触面积，以量化细胞铺展动力学。壳聚糖表面和对照表面在细胞铺展反应方面存在显著差异，而两组均表现出S形动力学行为，最初铺展速率升高，在黏附的第二个小时稳定下来。用共聚焦显微镜观察后证实了肌动蛋白丝的结构变化。生物材料表面改性可以增强成骨细胞的力学反应，并诱导有利于植入物整合的结构组织。
