Stimulation of in vivo angiogenesis by in situ crosslinked, dual growth factor-loaded, glycosaminoglycan hydrogels.
As part of a study of elicited angiogenesis, hyaluronan (HA)-based hydrogels crosslinked by polyethylene glycol diacrylate (PEGDA) were loaded with combinations of the cytokine growth factors vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), keratinocyte growth factor (KGF) and platelet-derived growth factor (PDGF). GF release in vivo was controlled by covalent incorporation of thiol-modified heparin into thiolated HA hydrogels, which were injected into the ear pinnae of mice and allowed to crosslink in situ. GF release in vivo was controlled by covalent incorporation of thiol-modified heparin in the gels. The ears were harvested at 7 or 14 days post-implantation, and vascularization evaluated via a Neovascularization Index (NI). The study demonstrates that in situ gelling implants produced no gross inflammation, redness or swelling, and an improved tolerance compared to HA-based dry film implants. All treatments showed significantly more vascularization than either contralateral ears or ears receiving a sham surgery. The maximum response was observed after 14 days in the ears receiving 0.3% Hp, gelatin-containing gels loaded with VEGF + KGF (NI = 3.91). The study revealed injected growth factor-loaded HA-based hydrogels can successfully produce localized controllable vascularization, while minimizing tissue necrosis, polymorphonuclear leukocytes and inflammation. The ability to target and controllably release growth factors can prove a useful tool in specific diseased tissue/organ angiogenesis.
Department of Biomedical Engineering, Science and Technology Center, Tufts University, Medford, MA 02155, USA. roberto.elia@tufts.edu
Roberto
R
Elia
Peter W
PW
Fuegy
Aaron
A
VanDelden
Matthew A
MA
Firpo
Glenn D
GD
Prestwich
Robert A
RA
Peattie
D042683:Angiopoietin-1 / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D051523:Fibroblast Growth Factor 7 / Q000737:chemistry / Q000494:pharmacology; D006025:Glycosaminoglycans / Q000737:chemistry*; D006493:Heparin / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry* / Q000494:pharmacology*; D051379:Mice; D015394:Molecular Structure; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010982:Platelet-Derived Growth Factor / Q000737:chemistry / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000494:pharmacology
D042683:Angiopoietin-1; D006025:Glycosaminoglycans; D020100:Hydrogels; D010982:Platelet-Derived Growth Factor; D042461:Vascular Endothelial Growth Factor A; D051523:Fibroblast Growth Factor 7; D006493:Heparin