Inhibition of Mesenchymal Cell Contraction using Carbon Nanotubes

Abstract

Fibrosis can develop after injury in many organ systems, including the skin, lungs, and heart, yet no treatment is currently available to target the cause of fibrosis. We hypothesize that fiber-like carbon nanotubes may be able to interact with the mesenchymal cells to inhibit the contraction that can lead to fibrosis. Collagen gels were populated with human mesenchymal cells and spherical carbon black nanoparticles, singlewall carbon nanotubes (SWNT), or multi-wall carbon nanotubes (MWNT). The contraction, viability, actin content, and antioxidant capabilities of the gels were evaluated over the course of one week. The initial mechanical properties of the gels were also investigated. Both SWNT and MWNT, but not carbon black, significantly inhibited contraction while increasing proliferation. The nanotubes were effective even though cells in every gel type expressed α-smooth muscle actin, which is indicative of a procontractile, myofibroblast phenotype. The nanoparticles were shown to not affect gel stiffness. The MWNT also act as potent antioxidants, which may be the reason they minimize contraction. Our data show that carbon nanotubes can modulate the pathological activity of mesenchymal cells while increasing cell proliferation. We demonstrate that the aspect ratio of carbon nanoparticles is an important factor in mediating nanoparticle-cell interactions. Keywords Fibrosis • Collagen Gel • MWNT • SWNT • Carbon Black