Scaffolds with covalently immobilized VEGF and Angiopoietin-1 for vascularization of engineered tissues.
The aim of this study was to engineer a biomaterial capable of supporting vascularization in vitro and in vivo. We covalently immobilized vascular endothelial growth factor (VEGF) and Angiopoietin-1 (Ang1) onto three-dimensional porous collagen scaffolds using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) chemistry. Over both 3 and 7 days in vitro, seeded endothelial cells (ECs) had increased proliferation on scaffolds with immobilized VEGF and/or Ang1 compared to unmodified scaffolds and soluble growth factor controls. Notably, the group with co-immobilized VEGF and Ang1 showed significantly higher cell number (P=0.0079), higher overall lactate production rate (P=0.0044) and higher overall glucose consumption rate (P=0.0034) at Day 3, compared to its corresponding soluble control for which growth factors were added to culture medium. By Day 7, hematoxylin and eosin, live/dead, CD31, and von Willebrand factor staining all showed improved tube formation by ECs when cultivated on scaffolds with co-immobilized growth factors. Interestingly, scaffolds with co-immobilized VEGF and Ang1 showed increased EC infiltration in the chorioallantoic membrane (CAM) assay, compared to scaffolds with independently immobilized VEGF/Ang1. This study presents an alternative method for promoting the formation of vascular structures, via covalent immobilization of angiogenic growth factors that are more stable than soluble ones and have a localized effect.
Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, Ontario M5S 3E5, Canada.
Loraine L Y
LL
Chiu
Milica
M
Radisic
D042683:Angiopoietin-1 / Q000494:pharmacology*; D000818:Animals; D001681:Biological Assay; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000187:drug effects / Q000378:metabolism; D003094:Collagen / Q000494:pharmacology; D017364:Collagenases / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D055767:Immobilized Proteins / Q000494:pharmacology*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D012995:Solubility / Q000187:drug effects; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
D042683:Angiopoietin-1; D006454:Hemoglobins; D055767:Immobilized Proteins; D042461:Vascular Endothelial Growth Factor A; D003094:Collagen; D017364:Collagenases