ABSTRACT
CONTENTS 6.1 Introduction 151 6.2Assessment of Cell-Material Interactions151
6.2.1Evaluation of Ligand-Receptor Interactions at the Molecular Level152 6.2.1.1Kinetics and …ermodynamics of Molecular Recognition153 6.2.1.2Examination of Molecular Interactions of Free Molecules154 6.2.1.3Examination of the Molecular Interactions between Ligands
and Immobilized Receptors155 6.3Evaluation of Cell Behavior on the Surface of Materials 158
6.3.1Cell Source and Cell Culture158 6.3.2Evaluation of Cell Adhesion159 6.3.3Evaluation of Cell Migration160 6.3.4Evaluation of Cell Proliferation160
Acknowledgment161 References161
152
Cole et al. 2009). …us, numerous approaches were developed in the past few decades to achieve cell adhesion or increase the resistance to cell adhesion on material surfaces. In general, the speci‡c molecular recognition between ligands and cell receptors is used to enhance the interactions between cells and materials. Numerous aµnity molecules have been derived from biological systems or chemically synthesized for this need (Shin et al. 2003). …e most commonly used aµnity molecules include gelatin, antibodies, and short peptides. …ese aµnity molecules have been primarily used to functionalize materials to mimic the functionality of extracellular matrices for tissue engineering and regenerative medicine research and applications (Shin et al. 2003). Some of these applications require the prevention of cell adhesion, for the uncontrolled adhesion and accumulation of cells onto synthetic surfaces can adversely aŽect the functionality of various medical devices (Kingshott and Griesser 1999). At the molecular level, proteins and lipids can be rapidly adsorbed to the “naked” synthetic surface (i.e., bioadhesion), leading to subsequent adhesion of other molecules and cells (Kingshott and Griesser 1999). …erefore, research activities have been focused on modifying material surfaces to increase the resistance to bioadhesion. Various approaches and coating materials have been studied toward improving bioadhesion resistance. Of them, poly(ethylene glycol) (PEG)-based coatings have attracted the most attention (Ratner and Bryant 2004). …e PEG polymers can be attached to a material surface through covalent conjugations, physical adsorption, or molecular interpenetration (Ratner and Bryant 2004). …e use of optimized surface PEGylation can result in undetectable protein and cell adhesion for up to a month under normal cell culture conditions (Ma et al. 2006). Besides the studies aimed at promoting cell adhesion or increasing the resistance to cell adhesion, great eŽorts have also been made in developing materials and methods that can be used for capturing and releasing cells at speci‡c time points (Cole et al. 2009). For instance, thermo-or photosensitive polymers or ligands can be immobilized on solid surfaces (Kushida et al. 1999; Akiyama et al. 2004; Auernheimer et al. 2005; Canavan et al. 2005; Yang et al. 2005; da Silva et al. 2007; Ohmuro-Matsuyama and Tatsu 2008). …ese polymers and ligands can be triggered by temperature or ultraviolet light and switch from an active to an inactive state. …is feature can lead to the modulation of cell attachment on material surfaces. …ese reversible biointerfaces have been primarily investigated for monolayer cell cultures (Kushida et al. 1999; Akiyama et al. 2004; Auernheimer et al. 2005; Canavan et al. 2005; Yang et al. 2005; da Silva et al. 2007; Ohmuro-Matsuyama and Tatsu 2008), which have great potential for regenerative engineering applications. To limit the scope of discussion, this section does not elaborate on functionalizing material surfaces. …e relevant information has been well described earlier. …is section primarily focuses on the methodology for assessing cell-material interactions at the molecular and cellular level.
