Covalently-Immobilized Vascular Endothelial Growth Factor Promotes Endothelial Cell Tubulogenesis in Poly(ethylene glycol) Diacrylate Hydrogels

TitleCovalently-Immobilized Vascular Endothelial Growth Factor Promotes Endothelial Cell Tubulogenesis in Poly(ethylene glycol) Diacrylate Hydrogels
Publication TypeJournal Article
Year of Publication2009
AuthorsLeslie-Barbick, JE, Moon, JJ, West, JL
JournalJournal of Biomaterials Science, Polymer Edition
Volume20
Issue12
Pagination1763 - 1779
Date Published01/2009
ISSN1568-5624
KeywordsAngiogenesis; hydrogels; PEG; VEGF
Abstract

The development and use of functional tissue-engineered products is currently limited by the challenge of incorporating microvasculature. To this end, we have investigated strategies to facilitate vascularization in scaffold materials, in this case poly(ethylene glycol) (PEG) hydrogels. These hydrogels are hydrophilic and resist protein adsorption and subsequent non-specific cell adhesion, but can be modified to contain cell-adhesive ligands and growth factors to support cell and tissue function. Additionally, the hydrogel matrix can include proteolytically degradable peptide sequences in the backbone of the structure to allow cells to control scaffold biodegradation, allowing three-dimensional migration. Vascular endothelial growth factor (VEGF), a potent angiogenic signal, and the cell-adhesive peptide RGDS were each covalently attached to PEG monoacrylate linkers. PEGylated RGDS and VEGF were then covalently immobilized in PEG-diacrylate (PEGDA) hydrogels in 2D and 3D. Immobilized VEGF increased endothelial cell tubulogenesis on the surface of non-degradable PEGDA hydrogels 4-fold compared to controls without the growth factor. Endothelial cell behavior in 3D collagenase-degradable hydrogels modified with RGDS and VEGF was observed using time-lapse confocal microscopy. Bulk immobilization of VEGF in 3D collagenase-degradable RGDS-modified hydrogels increased endothelial cell motility 14-fold and cell-cell connections 3-fold. Covalent incorporation of PEGylated VEGF in PEG hydrogels can be a useful tool to promote endothelial cell migration, cell-cell contact formation and tubulogenesis in an effort to produce vascularized tissue-engineered constructs.

DOI10.1163/156856208X386381
Short TitleJ Biomater Sci Polym Ed
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