title: Simple surface coating of electrospun poly-L-lactic acid scaffolds to induce angiogenesis.
abstract: Tissue-engineered constructs often fail due to poor integration with the patient's tissues. Specifically, they fail to be neovascularised, leading to the death and loss of the implanted tissues. Thus, there is a need to produce angiogenic materials to improve tissue integration. We describe the development of a layer-by-layer approach to coat electrospun scaffolds to help promote angiogenesis into these biomaterials once implanted. Electrospun poly-L-lactic acid was coated comparing two different techniques - one using alternative layers of polyethyleneImine (PEI) and polyacrylic Acid (PAC) and one with alternative layers of PEI and heparin for a total of seven layers in both cases. Both scaffolds were then coated with heparin as the final layer. The scaffold coated with alternate PEI and PAC showed a clear ability to bind the most heparin. This scaffold was then studied further for its ability to bind vascular endothelial growth factor, which was confirmed using an ELISA. The scaffold coated with seven alternate layers of PEI and PAC and heparin was then implanted in a chick chorionic allantoic membrane (CAM) assay. After a period of 7 days in the CAM, the coated scaffold showed strong angiogenic activity. In contrast, the uncoated scaffolds did not promote angiogenesis. We conclude that this approach to functionalising scaffolds is effective within a clinically relevant time period (7 days in an in-vivo angiogenic model) and suggest this will be useful for improving integration of scaffolds once implanted.
authors: Materials Science and Engineering, North Campus, University of Sheffield, Broad Lane, Sheffield, UK.
authors: Giulia
authors: G
authors: Gigliobianco
authors: Materials Science and Engineering, North Campus, University of Sheffield, Broad Lane, Sheffield, UK.
authors: Chuh K
authors: CK
authors: Chong
authors: Materials Science and Engineering, North Campus, University of Sheffield, Broad Lane, Sheffield, UK s.macneil@sheffield.ac.uk.
authors: Sheila
authors: S
authors: MacNeil
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000378:metabolism; D043925:Angiogenesis Inducing Agents / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D002645:Chickens; D049033:Chorioallantoic Membrane / Q000098:blood supply / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D006493:Heparin / Q000737:chemistry / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry* / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D011091:Polyesters; D011094:Polyethyleneimine / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D000180:Acrylic Resins; D043925:Angiogenesis Inducing Agents; D020099:Coated Materials, Biocompatible; D011091:Polyesters; D011108:Polymers; D042461:Vascular Endothelial Growth Factor A; D019344:Lactic Acid; C033616:poly(lactide); C006903:carbopol 940; D011094:Polyethyleneimine; D006493:Heparin
keywords: ELISA; Poly-L-lactic acid; chick chorionic allantoic membrane; electrospinning; heparin; layer-by-layer; plasma polymerisation; vascular endothelial growth factor