title: [PEG-mediated covalent binding of VEGF to decellularized aortic valves promotes adhesion and proliferation of endothelial progenitor cells].
abstract: OBJECTIVE
  To improve the biological properties of decellularized aortic valves by polyethylene glycol (PEG)-mediated covalent incorporation of vascular endothelial growth factor (VEGF).
  
  
  METHODS
  PEG crosslinking of decellularized aortic valves were completed via a Michael-type addition reaction, followed by covalent incorporation of VEGF through another Michael-type addition reaction between the unsaturated propylene acyl of PEG and the thiol groups on cysteine residues of VEGF. The effect of VEGF incorporation was evaluated by enzyme-linked immunosorbent assay (ELISA) and immune fluorescence assay. The endothelial progenitor cells (EPCs) were seeded on decellularized aortic valves with or without these modifications, and after 10 days of culture, the valves were examined for DNA content and by hematoxylin-eosin staining and scanning electron microscopy.
  
  
  RESULTS
  Immune fluorescence and ELISA showed that the maximal VEGF incorporation on the decellularized aortic valve reached 908.94∓0.27 pg. Compared with the unmodified valves and the valves with PEG crosslinking, decellularized aortic valves with covalent incorporation of VEGF significantly promoted the adhesion and proliferation of EPCs, which formed a confluent cell monolayer on the valve surface.
  
  
  CONCLUSIONS
  PEG-mediated covalent incorporation of VEGF in the decellularized aortic valves improves the adhesion and proliferation of the seeded EPCs to facilitate the construction of tissue-engineered heart valves.
authors.affiliation: Department of Cardiovascular Surgery, Huazhong University of Science and Technology, Wuhan 430022, China. zhoujianliang2010@163.com
authors.forename: Jian-liang
authors.initials: JL
authors.lastname: Zhou
authors.forename: Ming-hui
authors.initials: MH
authors.lastname: Zou
authors.forename: Yi-chu
authors.initials: YC
authors.lastname: Chen
authors.forename: Cui-fen
authors.initials: CF
authors.lastname: Lu
authors.forename: Jia-wei
authors.initials: JW
authors.lastname: Shi
authors.forename: Nian-guo
authors.initials: NG
authors.lastname: Dong
mesh_terms: D000818:Animals; D001021:Aortic Valve / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects; D006350:Heart Valve Prosthesis; D011092:Polyethylene Glycols / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects; D013552:Swine; D023822:Tissue Engineering; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
chemical_list: D042461:Vascular Endothelial Growth Factor A; D011092:Polyethylene Glycols