Multiwalled carbon nanotube buckypaper: toxicology and biological effects in vitro and in vivo

Aim: We evaluated the effect of buckypaper (BP) on cancer and primary cell lines in vitro and in vivo in laboratory rats. BP is an innovative material with interesting physical/chemical properties that has possible pharmacological and prosthetic employment. Given that precautions need to be taken where carbon nanotubes are injected into human body for drug delivery, as contrast agent-carrying entities for MRI or as the material of a new prosthesis generation, we assessed the toxicity of BP carbon nanotubes. BP has structural resemblance to asbestos, whose toxicity has been linked to cancer. Results: BP decreased proliferation of human colorectal, breast and leukemic cancer cell lines in vitro. However, BP had no effect on the proliferation and viability of normal human arterial smooth muscle cells and human dermal fibroblasts in vitro. In vivo, BP induced a moderate inflammatory reaction but had no mutagenic effects. After BP implantation the animals showed an inflammatory reaction followed 2 weeks later by a cicatrization reaction with the organization and fibrosis of the scar. Conclusion: These results show a low toxicity of BP both in vitro and in vivo.