Controlled compaction with ruthenium-catalyzed photochemical cross-linking of fibrin-based engineered connective tissue

Zeeshan H. Syedain, Jason Bjork, Lillian Sando, Robert T. Tranquillo

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Tissue engineering utilizing fibrin gel as a scaffold has the advantage of creating a completely biological replacement. Cells seeded in a fibrin gel can induce fibril alignment by traction forces when subjected to appropriate mechanical constraints. While gel compaction is key to successful tissue fabrication, excessive compaction can result due to low gel stiffness. This study investigated using ruthenium-catalyzed photo-cross-linking as a method to increase gel stiffness in order to minimize over-compaction. Cross-links between the abundant tyrosine molecules that comprise fibrin were created upon exposure to blue light. Cross-linking was effective in increasing the stiffness of the fibrin gel by 93% with no adverse effects on cell viability. Long-term culture of cross-linked tubular constructs revealed no detrimental effects on cell proliferation or collagen deposition due to cross-linking. After 4 weeks of cyclic distension, the cross-linked samples were more than twice as long as non-cross-linked controls, with similar cell and collagen contents. However, the cross-linked samples required a longer incubation period to achieve a UTS and modulus comparable to controls. This study shows that photo-cross-linking is an attractive option to stiffen the initial fibrin gel and thereby reduce cell-induced compaction, which can allow for longer incubation periods and thus more tissue growth without compaction below a useful size.

Original languageEnglish (US)
Pages (from-to)6695-6701
Number of pages7
Issue number35
StatePublished - Dec 2009

Bibliographical note

Funding Information:
The authors acknowledge Naomi Ferguson and Cary Valley for technical assistance. Funding was provided by NIH BRP HL71538 to R.T.T.


  • Cross-linking
  • Fibrin
  • Fibroblast
  • Tissue engineering


Dive into the research topics of 'Controlled compaction with ruthenium-catalyzed photochemical cross-linking of fibrin-based engineered connective tissue'. Together they form a unique fingerprint.

Cite this