Controlled growth factor release from synthetic extracellular matrices

Polymeric matrices can be used to grow new tissues and organs(1,2), and the delivery of growth factors from these matrices is one method to regenerate tissues(3,4). A problem with engineering tissues that exist in a mechanically dynamic environment, such as bone, muscle and blood vessels(5,6), is that most drug delivery systems have been designed to operate under static conditions. We thought that polymeric matrices, which release growth factors in response to mechanical signals, might provide a new approach to guide tissue formation in mechanically stressed environments. Critical design features for this type of system include the ability to undergo repeated deformation, and a reversible binding of the protein growth factors to polymeric matrices to allow for responses to repeated stimuli. Here we report a model delivery system that can respond to mechanical signalling and upregulate the release of a growth factor to promote blood vessel formation. This approach may rnd a number of applications, including regeneration and engineering of new tissues and more general drug-delivery applications.