Heparin-functionalized materials in tissue engineering applications

Abstract

Over the past decade, the tissue engineering field has placed increasing emphasis on the development of materials that mimic the natural cellular microenvironment and the complexity inherent to biological systems. Understanding cell and molecular biology has become as important to the development of tissue engineering scaffolds as traditional material science. This emphasis on biological mimicry has led to interest in materials that incorporate the dynamic and complex interactions found in the native extracellular matrix (ECM); protein-saccharide interactions in the ECM are one such example. In particular, over the past decade the glycosaminoglycan (GAG) heparin has found a tremendous amount of use in the design of tissue engineering scaffolds and drug delivery devices, as well as in more traditional applications. Both heparin and its biological counterpart, heparan sulfate, interact - mainly electrostatically - with a number of proteins and play an important role in many biological processes. This has been put to use in tissue engineering approaches to sequester and deliver the factors that drive regenerative processes. Additionally, heparin has been utilized in the development of novel responsive materials that form hydrogels through physical assembly. The versatility provided by these approaches has afforded opportunities not only in the design of scaffolds for tissue engineering but also in the development of drug delivery devices.