title: Engineered microenvironments for synergistic VEGF - Integrin signalling during vascularization.
abstract: We have engineered polymer-based microenvironments that promote vasculogenesis both in vitro and in vivo through synergistic integrin-growth factor receptor signalling. Poly(ethyl acrylate) (PEA) triggers spontaneous organization of fibronectin (FN) into nanonetworks which provide availability of critical binding domains. Importantly, the growth factor binding (FNIII12-14) and integrin binding (FNIII9-10) regions are simultaneously available on FN fibrils assembled on PEA. This material platform promotes synergistic integrin/VEGF signalling which is highly effective for vascularization events in vitro with low concentrations of VEGF. VEGF specifically binds to FN fibrils on PEA compared to control polymers (poly(methyl acrylate), PMA) where FN remains in a globular conformation and integrin/GF binding domains are not simultaneously available. The vasculogenic response of human endothelial cells seeded on these synergistic interfaces (VEGF bound to FN assembled on PEA) was significantly improved compared to soluble administration of VEGF at higher doses. Early onset of VEGF signalling (PLCγ1 phosphorylation) and both integrin and VEGF signalling (ERK1/2 phosphorylation) were increased only when VEGF was bound to FN nanonetworks on PEA, while soluble VEGF did not influence early signalling. Experiments with mutant FN molecules with impaired integrin binding site (FN-RGE) confirmed the role of the integrin binding site of FN on the vasculogenic response via combined integrin/VEGF signalling. In vivo experiments using 3D scaffolds coated with FN and VEGF implanted in the murine fat pad demonstrated pro-vascularization signalling by enhanced formation of new tissue inside scaffold pores. PEA-driven organization of FN promotes efficient presentation of VEGF to promote vascularization in regenerative medicine applications.
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom.
authors.forename: Vladimíra
authors.initials: V
authors.lastname: Moulisová
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonzalez-García
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom.
authors.forename: Marco
authors.initials: M
authors.lastname: Cantini
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom.
authors.forename: Aleixandre
authors.initials: A
authors.lastname: Rodrigo-Navarro
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Weaver
authors.affiliation: Departament de Bioquimica i Biologia Molecular, Universitat de València, Burjassot, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Costell
authors.affiliation: Centre for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valencia, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Sabater I Serra
authors.affiliation: Centre for Cell Engineering, Institute of Molecular Cell and Systems Biology, University of Glasgow, Joseph Black Bld, University Avenue, Glasgow G12 8QQ, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Dalby
authors.affiliation: Woodruff School of Mechanical Engineering, Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Andrés J
authors.initials: AJ
authors.lastname: García
authors.affiliation: Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom. Electronic address: Manuel.Salmeron-Sanchez@glasgow.ac.uk.
authors.forename: Manuel
authors.initials: M
authors.lastname: Salmerón-Sánchez
mesh_terms: D000818:Animals; D060833:Cellular Microenvironment; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016023:Integrins / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D009154:Mutation / Q000235:genetics; D018919:Neovascularization, Physiologic; D051966:Phospholipase C gamma / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D015398:Signal Transduction; D023822:Tissue Engineering / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D005353:Fibronectins; D016023:Integrins; D042461:Vascular Endothelial Growth Factor A; D051416:Focal Adhesion Protein-Tyrosine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D051966:Phospholipase C gamma
keywords: Fibronectin; Growth factors; Protein assembly; VEGF; Vascularization; poly(ethyl acrylate)