Department of Mechanical Engineering, University of Maine, 5711 Boardman Hall, Room 206, Orono, Maine 04469-5711, USA.
Biotechnol Bioeng. 2010 Jan 1;105(1):172-83. doi: 10.1002/bit.22509.
Gradient distribution of bio-adhesive proteins can regulate multiple cellular processes, including adhesion, growth, and migration. The ability to control the cell function by changing the surface density of immobilized ligands has become increasingly important in design of implantable medical devices and tissue regenerating scaffolds. Recent techniques in fabrication of substrates with controlled surface properties allow the examination of cell sensitivity to a wide range of adhesion gradients. Understanding the mechanisms by which cells sense and respond to these directional cues warrants a quantitative assessment of macroscopic cellular response to the surface gradients, supported by predictive theoretical models. This article presents a theoretical basis to examine the effect of ligand gradients on cellular adhesion, using an equilibrium thermodynamic model. The model facilitates a systematic investigation of the complex interplay of cell-substrate specific adhesions, non-specific repulsions, and membrane elasticity. This purely mechanistic model predicts a biphasic dependence between the extent of cell spreading and its position across the gradient substrate.
生物黏附蛋白的梯度分布可以调节多种细胞过程，包括黏附、生长和迁移。通过改变固定配体的表面密度来控制细胞功能的能力在可植入医疗器械和组织再生支架的设计中变得越来越重要。最近的基底表面特性控制制造技术允许研究细胞对广泛的黏附梯度的敏感性。为了定量评估细胞对表面梯度的宏观响应，需要了解细胞感知和响应这些定向信号的机制，这需要由预测理论模型提供支持。本文使用平衡热力学模型，为研究配体梯度对细胞黏附的影响提供了理论基础。该模型有助于系统地研究细胞-基底特异性黏附、非特异性排斥和膜弹性之间的复杂相互作用。这种纯粹的力学模型预测细胞铺展程度与其在梯度基底上位置之间存在双相依赖性。
