title: Two-photon polymerization of polyethylene glycol diacrylate scaffolds with riboflavin and triethanolamine used as a water-soluble photoinitiator.
abstract: OBJECTIVE
  In this study, the suitability of a mixture containing riboflavin (vitamin B2) and triethanolamine (TEOHA) as a novel biocompatible photoinitiator for two-photon polymerization (2PP) processing was investigated.
  
  
  METHODS
  Polyethylene glycol diacrylate was crosslinked using Irgacure(®) 369, Irgacure 2959 or a riboflavin-TEOHA mixture; biocompatibility of the photopolymer extract solutions was subsequently assessed via endothelial cell proliferation assay, endothelial cell viability assay and single-cell gel electrophoresis (comet) assay. Use of a riboflavin-TEOHA mixture as a photoinitiator for 2PP processing of a tissue engineering scaffold and subsequent seeding of this scaffold with GM-7373 bovine aortic endothelial cells was also demonstrated.
  
  
  RESULTS
  The riboflavin-TEOHA mixture was found to produce much more biocompatible scaffolds than those produced with Irgacure 369 or Irgacure 2959.
  
  
  CONCLUSIONS
  The results suggest that riboflavin is a promising component of photoinitiators for 2PP fabrication of tissue engineering scaffolds and other medically relevant structures (e.g., biomicroelectromechanical systems).
authors.affiliation: JUNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina, Campus Box 7575, Chapel Hill, NC 27599-7575, USA.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Nguyen
authors.forename: Shaun D
authors.initials: SD
authors.lastname: Gittard
authors.forename: Anastasia
authors.initials: A
authors.lastname: Koroleva
authors.forename: Sabrina
authors.initials: S
authors.lastname: Schlie
authors.forename: Arune
authors.initials: A
authors.lastname: Gaidukeviciute
authors.forename: Boris N
authors.initials: BN
authors.lastname: Chichkov
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Narayan
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D001672:Biocompatible Materials / Q000494:pharmacology; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D004983:Ethanolamines / Q000737:chemistry* / Q000494:pharmacology; D005452:Fluoresceins / Q000378:metabolism; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D058567:Photoinitiators, Dental / Q000737:chemistry*; D017785:Photons; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000494:pharmacology; D058105:Polymerization; D012256:Riboflavin / Q000737:chemistry* / Q000494:pharmacology; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D054457:Tissue Scaffolds / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004983:Ethanolamines; D005452:Fluoresceins; D058567:Photoinitiators, Dental; C437167:poly(ethylene glycol)diacrylate; D014867:Water; C085925:calcein AM; D011092:Polyethylene Glycols; C009546:triethanolamine; D012256:Riboflavin