title: Increased angiogenesis and blood vessel maturation in acellular collagen-heparin scaffolds containing both FGF2 and VEGF.
abstract: An important issue in tissue engineering is the vascularisation of the implanted construct, which often takes several weeks. In vivo, the growth factors VEGF and FGF2 show a combined effect on both angiogenesis and maturation of blood vessels. Therefore, we hypothesise that the addition of these growth factors to an acellular construct increases blood vessel formation and maturation. To systematically evaluate the contribution of each scaffold component with respect to tissue response and in particular to blood vessel formation, five porous scaffolds were prepared and characterised, viz.: collagen, collagen with heparin, and collagen with heparin plus one or two growth factors (rrFGF2 and rrVEGF). Scaffolds were subcutaneously implanted in 3 months old Wistar rats. Of all scaffolds tested, the one with a combination of growth factors displayed the highest density of blood vessels (type IV collagen) and most mature blood vessels (smooth muscle actin). In addition, no hypoxic cells were found in this scaffold at day 7 and 21 (hypoxia inducible factor 1-alpha). These results indicate that the addition of both FGF2 and VEGF to an acellular construct enhances an early mature vasculature. This opens prospects for (acellular) tissue-engineered constructs in conditions as ischaemic heart disease or diabetic ulcers.
authors.affiliation: Department of Biochemistry 280, NCMLS, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Suzan T M
authors.initials: ST
authors.lastname: Nillesen
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Geutjes
authors.forename: Ronnie
authors.initials: R
authors.lastname: Wismans
authors.forename: Joost
authors.initials: J
authors.lastname: Schalkwijk
authors.forename: Willeke F
authors.initials: WF
authors.lastname: Daamen
authors.forename: Toin H
authors.initials: TH
authors.lastname: van Kuppevelt
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001705:Bioprosthesis; D001807:Blood Vessel Prosthesis; D001808:Blood Vessels / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D002474:Cell-Free System; D002478:Cells, Cultured; D003094:Collagen / Q000008:administration & dosage / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D005109:Extracellular Matrix / Q000737:chemistry; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage* / Q000737:chemistry; D006493:Heparin / Q000008:administration & dosage / Q000737:chemistry*; D020007:Implants, Experimental; D008422:Materials Testing; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D006493:Heparin; D003094:Collagen