Directional conductivity in SWNT-collagen-fibrin composite biomaterials through strain-induced matrix alignment

Christopher M. Voge, Mihalis Kariolis, Rebecca A. MacDonald, Jan P. Stegemann

Research output: Contribution to journalArticlepeer-review

60 Scopus citations


Composite biomaterials incorporating fibroblast cells, collagen Type I, fibrin, and 2 wt % carboxylated SWNT were created, and their properties were compared with similar control constructs without SWNT. Alignment of the matrix was stimulated by application of 8% cyclic strain for three 12-h periods over three days. All constructs underwent cell-mediated gel compaction to 15-20% of their initial volume, which was not affected by SWNT loading. Mechanical strain increased the rate of compaction, and strained constructs were significantly more compacted than unstrained controls by day 3. Cell viability and morphology were similar in both control and SWNT-loaded constructs, but unstrained samples exhibited a more stellate appearance with more numerous cellular projections. Application of mechanical strain caused clear alignment of both the cells and matrix in the direction of the applied strain. Bioimpedance measurements showed that SWNT loading increased the electrical conductivity of composite constructs, and that mechanically-induced alignment of the matrix/SWNT caused a further increase in conductivity. These results demonstrate that SWNT can be used to augment the electrical properties of 3D protein hydrogels, and that anisotropy in the matrix further enhances these properties. Such electrically conductive biopolymers may have a variety of applications in tissue engineering and biosensor development.

Original languageEnglish (US)
Pages (from-to)269-277
Number of pages9
JournalJournal of Biomedical Materials Research - Part A
Issue number1
StatePublished - Jul 2008
Externally publishedYes


  • Biomaterials
  • Bioreactor
  • Carbon nanotubes
  • Collagen gel
  • Electrical conductivity
  • Fibrin gel
  • Nanotechnology

ASJC Scopus subject areas

  • Ceramics and Composites
  • Biomaterials
  • Biomedical Engineering
  • Metals and Alloys


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