Two-photon polymerization of polyethylene glycol diacrylate scaffolds with riboflavin and triethanolamine used as a water-soluble photoinitiator

Regen Med. 2013 Nov;8(6):725-38. doi: 10.2217/rme.13.60.


Aim: 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.

Materials & 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.

Conclusion: 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).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / cytology
  • Biocompatible Materials / pharmacology
  • Cattle
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Comet Assay
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Ethanolamines / chemistry*
  • Ethanolamines / pharmacology
  • Fluoresceins / metabolism
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Photoinitiators, Dental / chemistry*
  • Photons*
  • Polyethylene Glycols / chemistry*
  • Polyethylene Glycols / pharmacology
  • Polymerization*
  • Riboflavin / chemistry*
  • Riboflavin / pharmacology
  • Solubility
  • Spectrophotometry, Ultraviolet
  • Tissue Scaffolds / chemistry
  • Water / chemistry*


  • Biocompatible Materials
  • Ethanolamines
  • Fluoresceins
  • Photoinitiators, Dental
  • poly(ethylene glycol)diacrylate
  • Water
  • calcein AM
  • Polyethylene Glycols
  • triethanolamine
  • Riboflavin