Biologically Inspired Materials In Tissue Engineering

The extracellular matrix (ECM) has unique biochemical, mechanical and organisational properties through which it provides a physical scaffolding for cells; a barrier that protects tissues; several signals that affect cell behaviour; and a reservoir for biologically active molecules. Considering the importance of ECM in regulating many fundamental cell processes, a myriad of strategies and materials has been developed to reproduce its properties. The first part of the chapter covers various approaches aiming to generate scaffolds whose fibre size, orientation and stiffness could mimic the ECM nanofibrous structure. In particular, the use of natural fibrous proteins, the application of electrospinning and freeze-drying and examples of tissue engineering applications are presented. The second part discusses strategies aiming to address the ECM ligand-binding function and to reproduce the dynamic, reciprocal, dialogue between cells and their microenvironment; examples of 3D scaffolds for controlled release of growth factors, drugs and genetic material are reported. Researchers have also used native ECM components to recapitulate the biochemical and biophysical properties of ECM. In the third part of the chapter, the use of fibrinogen and fibrin is presented as an example of natural scaffolds recapitulating ECM functions. Fibrinogen and fibrin can be used as provisional matrix in regenerating tissues; moreover, by varying the fabrication method and by blending them with other materials, it is possible to produce biodegradable scaffolds with reasonable control of degradation rate and drug release.