Keratocyte behavior in three-dimensional photopolymerizable poly(ethylene glycol) hydrogels

Acta Biomater. 2008 Sep;4(5):1139-1147. doi: 10.1016/j.actbio.2008.05.007. Epub 2008 May 27.


The goal of this study was to evaluate three-dimensional (3-D) poly(ethylene glycol) (PEG) hydrogels as a culture system for studying corneal keratocytes. Bovine keratocytes were subcultured in DMEM/F-12 containing 10% fetal bovine serum (FBS) through passage 5. Primary keratocytes (P0) and corneal fibroblasts from passages 1 (P1) and 3 (P3) were photoencapsulated at various cell concentrations in PEG hydrogels via brief exposure to light. Additional hydrogels contained adhesive YRGDS and nonadhesive YRDGS peptides. Hydrogel constructs were cultured in DMEM/F-12 with 10% FBS for 2 and 4 weeks. Cell viability was assessed by DNA quantification and vital staining. Biglycan, type I collagen, type III collagen, keratocan and lumican expression were determined by reverse transcriptase-polymerase chain reaction. Deposition of type I collagen, type III collagen and keratan sulfate (KS)-containing matrix components was visualized using confocal microscopy. Keratocytes in a monolayer lost their stellate morphology and keratocan expression, displayed elongated cell bodies, and up-regulated biglycan, type I collagen and type III collagen characteristic of corneal fibroblasts. Encapsulated keratocytes remained viable for 4 weeks with spherical morphologies. Hydrogels supported production of KS, type I collagen and type III collagen matrix components. PEG-based hydrogels can support keratocyte viability and matrix production. 3-D hydrogel culture can stabilize but not restore the keratocyte phenotype. This novel application of PEG hydrogels has potential use in the study of corneal keratocytes in a 3-D environment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biglycan
  • Biocompatible Materials / chemistry*
  • Cattle
  • Cell Culture Techniques / methods*
  • Cell Proliferation
  • Cell Survival
  • Cells, Cultured
  • Chondroitin Sulfate Proteoglycans / metabolism
  • Collagen / metabolism
  • Cornea / cytology*
  • Cornea / metabolism*
  • Extracellular Matrix Proteins / metabolism
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Hydrogels / chemistry
  • Keratan Sulfate / metabolism
  • Lumican
  • Materials Testing
  • Photochemistry / methods
  • Polyethylene Glycols / chemistry*
  • Proteoglycans / metabolism
  • Tissue Engineering / methods*


  • Biglycan
  • Biocompatible Materials
  • Chondroitin Sulfate Proteoglycans
  • Extracellular Matrix Proteins
  • Hydrogels
  • Lumican
  • Proteoglycans
  • Polyethylene Glycols
  • Collagen
  • Keratan Sulfate