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Carbon nanotubes increase the electrical conductivity of fibroblast-seeded collagen hydrogels

Paper ID Volume ID Publish Year Pages File Format Full-Text
1730 90 2008 10 PDF Available
Title
Carbon nanotubes increase the electrical conductivity of fibroblast-seeded collagen hydrogels
Abstract

Carbon nanotubes are attractive as additives in fiber-reinforced composites due to their high aspect ratio, strength and electrical conductivity. In the present study, solubilized collagen Type I was polymerized in the presence of dispersed single-walled carbon nanotubes (SWNT) and human dermal fibroblast cells (HDF) to produce collagen–SWNT composite biomaterials with HDF embedded directly in the matrix. The resulting constructs, with SWNT loadings of 0 (control), 0.8, 2.0 and 4.0 wt.% SWNT, were cultured and electrical properties were evaluated in the frequency range 5–500 kHz at days 3 and 7. All collagen–SWNT hydrogel matrices underwent HDF-mediated gel compaction over time in culture, but the presence of SWNT significantly decreased the rate and extent of gel compaction. Viability of HDF in all constructs was consistently high and cell morphology was not affected by the presence of SWNT. However, cell number at day 7 in culture decreased with increasing SWNT loading. Electrical conductivity of the constructs varied from 3 to 7 mS cm−1, depending on SWNT loading level. Conductivity increased uniformly with increasing wt.% of SWNT (R = 0.78) and showed a modest frequency dependence, suggesting that the electrical percolation threshold had not been reached in these materials. These data demonstrate that the electrical conductivity of cell-seeded collagen gels can be increased through the incorporation of carbon nanotubes. Protein–SWNT composite materials may have application as scaffolds for tissue engineering, as substrates to study electrical stimulation of cells, and as transducers or leads for biosensors.

Keywords
Composites; Single-walled nanotubes; Electrical conductivity; Collagen Type I; Fibroblasts
First Page Preview
Carbon nanotubes increase the electrical conductivity of fibroblast-seeded collagen hydrogels
Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 4, Issue 6, November 2008, Pages 1583–1592
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering