Abstract
Biomaterials are important for cell and tissue engineering. Chitosan is widely used as a scaffold because it is easily modified using its amino groups, can easily form a matrix, is stable under physiological conditions, and is inactive for cell adhesion. Chitosan is an excellent platform for peptide ligands, especially cell adhesive peptides derived from extracellular matrix (ECM) proteins. ECM proteins, such as collagen, fibronectin, and laminin, are multifunctional and have diverse cell attachment sites. Various cell adhesive peptides have been identified from the ECM proteins, and these are useful to design functional biomaterials. The cell attachment activity of peptides is influenced by the solubility, conformation, and coating efficiency to solid materials, whereas immobilization of peptides to a polysaccharide such as chitosan avoids these problems. Peptide⁻chitosan matrices promote various biological activities depending on the peptide. When the peptides are immobilized to chitosan, the activity of the peptides is significantly enhanced. Further, mixed peptide⁻chitosan matrices, conjugated with more than one peptide on a chitosan matrix, interact with multiple cellular receptors and promote specific biological responses via receptor cross-talk. Receptor cross-talk is important for mimicking the biological activity of ECM and the proteins. The mixed peptide⁻chitosan matrix approach is useful to develop biomaterials as a synthetic ECM for cell and tissue engineering.