Aligned Carbon Nanotubes Reduce Hypertrophic Scar via Regulating Cell Behavior

Hypertrophic scars, characterized by excessive cell proliferation, disordered cell growth, and aberrant deposition of collagens, could cause significant clinical problems. Herein, aligned carbon nanotubes (ACNTs) were synthesized via chemical vapor deposition, and bulk ACNTs were pulled out from the arrays. The capacity of the ACNTs to reduce hypertrophic scar formation was evaluated both in vitro and in vivo. The results demonstrated that the ACNTs suppressed the overproliferation of fibroblast cells, directed their growth, and inhibited collagen expression in vitro without cell cytotoxicity. Moreover, in vivo evaluation in a rabbit ear model indicated relieved scar hypertrophy after the ACNTs treatment. The gene expression microarray was further used to understand the mechanism, which showed that ACNTs could inhibit the TGFβ pathway to alter the components in the extracellular matrix, cell proliferation, cell cytoskeleton, and cell motility. These findings may provide a potent strategy of using carbon nanotubes in the bioengineering field.