Sustained Vascular Endothelial Growth Factor Delivery Enhances Angiogenesis and Perfusion in Ischemic Hind Limb

Purpose We hypothesized that sustained delivery of vascular endothelial growth factor (VEGF) using a polymer [85:15 poly(lactide-co-glycolide) (PLG)] would enhance angiogenesis and improve perfusion of ischemic tissue.Methods C57BL/6J mice (n = 20/group) underwent unilateral hind limb ischemia surgery and were randomized to groups of no scaffold implantation (∅-Implant), unloaded scaffold implantation (Empty-PLG), or implantation of scaffolds incorporating 3 μg of VEGF₁₆₅ (PLG-VEGF). Endpoints included laser Doppler perfusion imaging (LDPI, ischemic/nonischemic limb, %), local vessel counts, immunohistochemistry for CD31, and α-smooth muscle actin. In vitro release kinetics of VEGF from PLG was also measured.Results PLG-VEGF resulted in improved lower extremity perfusion vs. controls as measured by LDPI% at 7, 14, 21, and 28 days (p < 0.05). PLG-VEGF was associated with significantly greater percentage of vessels staining for CD31 and α-smooth muscle actin compared to the Empty-PLG or ∅-Implant (p < 0.05 for both).Conclusions The PLG-VEGF scaffolds resulted in sustained VEGF delivery, improved tissue perfusion, greater capillary density, and more mature vasculature compared to the controls. The sustained-release PLG polymer vehicle is a promising delivery system for therapeutic neovascularization applications.