Chemical strategies for the presentation and delivery of growth factors.

Since the first demonstration of employing growth factors (GFs) to control cell behaviour in vitro, the spatiotemporal availability of GFs in vivo has received continuous attention. In particular, the ability to physically confine the mobility of GFs has been used in various tissue engineering applications e.g. stents, orthopaedic implants, sutures and contact lenses. The lack of control over the mobility of GFs in scaffolds jeopardizes their performance in vivo. In this feature article, an overview is given on how to effectively present GFs on scaffolds. In the first part, non-covalent strategies are described covering interaction motifs that are generic to direct GF immobilization. In the second part, covalent strategies are described emphasizing the introduction of reactive groups in existing biomaterials. The feature article ends with a description of strategies based on the physical entrapment of growth factors.