Polymers for pro- and anti-angiogenic therapy.

Dysregulated growth factor signaling is traditionally targeted via bolus injections of therapeutic molecules, but this approach may not recreate necessary qualitative and quantitative aspects of biologic growth factor delivery systems. Polymeric delivery systems may, instead, mimic certain sequestration and binding characteristics of the extracellular matrix and lead to the provision of therapeutic molecules at therapeutically efficient local concentrations [V], in the form of spatial gradients (d[V]/dx) and temporal gradients (d[V]/dt), and in combination with other morphogenetic cues. Both physicochemical and biological attributes dictate their design, and they may be fabricated from synthetic and natural polymers. General concepts for manipulating growth factor signaling with these systems are discussed in the context of angiogenesis with vascular endothelial growth factor (VEGF), and these strategies may be broadly adapted to a multitude of other morphogens and growth factors.