Methods for photocrosslinking alginate hydrogel scaffolds with high cell viability

Tissue Eng Part C Methods. 2011 Feb;17(2):173-9. doi: 10.1089/ten.TEC.2009.0582. Epub 2010 Nov 4.


Methods for seeding high-viability (>85%) three-dimensional (3D) alginate-chondrocyte hydrogel scaffolds are presented that employ photocrosslinking of methacrylate-modified alginate with the photoinitiator VA-086. Comparison with results from several other photoinitiators, including Irgacure 2959, highlights the role of solvent, ultraviolet exposure, and photoinitiator cytotoxicity on process viability of bovine chondrocytes in two-dimensional culture. The radicals generated from VA-086 photodissociation are shown to be noncytotoxic at w/v concentrations up to 1.5%, enabling photocrosslinking without significant cell death. The applicability of these photoinitiators for generating 3D tissue-engineered constructs is evaluated by measuring cell viability in 3D constructs with aggregate moduli in the 10-20 kPa range. Hydrogels with encapsulated bovine chondrocytes were constructed with >85% viability using VA-086. While the commonly used Irgacure 2959 is noncytotoxic in its native state and crosslinks the alginate at weight fractions much lower than VA-086, the cytotoxicity of IRG2959's photogenerated radical leads to viabilities below 70% in the conditions tested.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acetamides / pharmacology*
  • Alginates / pharmacology*
  • Animals
  • Azo Compounds / pharmacology*
  • Cartilage, Articular / cytology
  • Cattle
  • Cell Aggregation / drug effects
  • Cell Aggregation / radiation effects
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Cells, Cultured
  • Chondrocytes / cytology*
  • Chondrocytes / drug effects
  • Chondrocytes / metabolism
  • Chondrocytes / radiation effects
  • Cross-Linking Reagents / pharmacology*
  • Glucuronic Acid / pharmacology
  • Hexuronic Acids / pharmacology
  • Hydrogel, Polyethylene Glycol Dimethacrylate / pharmacology*
  • Light*
  • Microscopy, Confocal
  • Tissue Engineering / methods*
  • Tissue Scaffolds / chemistry*


  • 2,2-azobis(2-methyl-N-(2-hydroxyethyl)propionamide
  • Acetamides
  • Alginates
  • Azo Compounds
  • Cross-Linking Reagents
  • Hexuronic Acids
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Glucuronic Acid