ABSTRACT
The science of tissue engineering takes an integrated approach to replacing nonfunctional or missing tissue by gathering input from many different scientific disciplines [1]. An integral part of the emergence of a mature tissue from cells both in vitro and in vivo involves guiding cells through their development. Apart from the choice of materials used for cell and tissue culture, the use of pharmacologically active substances such as cytokines and growth factors has emerged as an important tool in tissue engineering research and development in recent years [2-4]. By taking advantage of these substances at the right time and in the right context, cells can be induced to proliferate, differentiate, or to migrate in a controlled way. The positive impact of growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which both stimulate the vascularization of tissue in vivo, and members of the bone morphogenic protein family, used to enhance bone formation, illustrate how useful drug-delivery strategies have been for tissue engineering applications in recent years [5,6].
