Evaluation of an in situ chemically crosslinked hydrogel as a long-term vitreous substitute material

Acta Biomater. 2013 Feb;9(2):5022-30. doi: 10.1016/j.actbio.2012.09.026. Epub 2012 Sep 27.


Currently there is no material that can be used as a long-term vitreous substitute, and this remains an unmet clinical need in ophthalmology. In this study, we developed an injectable, in situ chemically crosslinked hydrogel system and evaluated it in a rabbit model. The system consisted of two components, both based on multi-functional poly(ethylene glycol) (PEG) but with complementarily reactive end groups of thiol and active vinyl groups, respectively. The two components are mixed and injected as a solution mixture, react in vivo via the Michael addition route and form a chemically crosslinked hydrogel in situ. The linkages between the end groups and the backbone PEG chains are specially designed to ensure that the final network structure is hydrolysis-resistant. In the rabbit study and with an optimized operation protocol, we demonstrated that the hydrogel indeed formed in situ after injection, and remained transparent and stable during the study period of 9 months without significant adverse reactions. In addition, the hydrogel formed in situ showed rheological properties very similar to the natural vitreous. Therefore, our study demonstrated that this in situ chemically crosslinked PEG gel system is suitable as a potential long-term vitreous substitute.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Death / drug effects
  • Cell Line
  • Cross-Linking Reagents / pharmacology*
  • Elastic Modulus / drug effects
  • Electroretinography
  • Endothelium, Corneal / drug effects
  • Endothelium, Corneal / pathology
  • Fluorescein Angiography
  • Fundus Oculi
  • Humans
  • Hydrogel, Polyethylene Glycol Dimethacrylate / pharmacology*
  • Intraocular Pressure / drug effects
  • Materials Testing*
  • Rabbits
  • Refractometry
  • Rheology / drug effects
  • Ultrasonography
  • Vitreous Body / diagnostic imaging
  • Vitreous Body / drug effects*
  • Vitreous Body / pathology
  • Vitreous Body / surgery


  • Cross-Linking Reagents
  • Hydrogel, Polyethylene Glycol Dimethacrylate