Angioma formation and angiogenesis in rats treated with phVEGF (a). Reprinted with permission from Schawrz et al., J. Am. Coll. Cardiol. 35, 1323 (2000). Copyright 2000 Elsevier. Enhanced angiogenesis by VEGF-expressing Marrow MSCs (reddish-brown). An increased number of vessels were observed in groups treated with gene delivery (b) compared to the control group (c). Reprinted with permission from Yang et al., Cardiology 107, 17 (2007). Copyright 2007 Karger Publishers, Basel, Switzerland. Serial Single-photon emission computed tomography (SPECT) myocardial perfusion images showed the bolus delivery of rhVEGF restored circulation and promoted angiogenesis in ischemic tissues (D). Reprinted with permission from Henry et al., Am. Heart. J. 142, 872 (2001). Copyright 2001 Elsevier. VEGF encapsulated in PLA scaffolds present in CAM. Histological analyses showed increased vessel number (arrowheads) in the PLA-VEGF scaffold (f) compared to control (e). Reprinted with permission from Kanczler et al., Biochem. Biophys. Res. Commun. 352,” 135 (2007). Copyright 2007 Elsevier. Hematoxylin and eosin staining images of mice ear tissue, heparin-HA-VEGF hydrogel showed greater neovascularization with well-defined vascular borders (g) compared to HA-VEGF specimen (h) and control (I). Reprinted with permission from Pike et al., Biomaterials 27, 5242 (2006). Copyright 2006 Elsevier. The covalent conjugation of ephrinA1 and PDGF to PEGDA hydrogels showed greater neovascularization (k) compared to PDGF-BB alone conjugation (j). Reprinted with permission from Saik et al., Biomacromolecules 12(7), 2715–2722 (2011). Copyright 2011 American Chemical Society. Vascularization analysis through fluorescent images perfused with lectin (green) to label vasculature after 14 days of implantation in mice in non-degradable microgel with VEGF (l), degradable microgel without VEGF (m), degradable microgel with a bolus injection of VEGF (n) and degradable microgel with VEGF (o). Reprinted with permission from Foster et al., Biomaterials 113,170 (2017). Copyright 2017 Elsevier. Fluorescence live (green)/dead (red) image of H5V cells on collagen scaffolds showed greater vessel formation (yellow arrows) in co-immobilized growth factor groups compared to single growth factor groups and control (p). Reprinted with permission from Chiu et al., Biomaterials 31, 226 (2010). Copyright 2010 Elsevier.