Progress Towards Single-Walled Carbon Nanotube Applications in Biomedicine and the Exoneration of Toxicity

Abstract

Single-walled carbon nanotubes exhibit unique photophysical properties that enable the detection of biomarkers, metabolites, and drugs in living cells, tissues, and organisms. The intrinsic near-infrared photoluminescence of nanotubes exhibits unique photostability and sensitivity to the local environment to transduce molecular binding events via changes in the nanotube optical bandgap. We developed carbon nanotube-based optical sensors to detect metabolites and cancer biomarkers in vivo, in order to improve early cancer detection and accelerate drug discovery for cancer and allied diseases. We introduced carbon nanotubes into disease models via implantation within devices, as well as by intravenous injection. In all cases, we found that properly-functionalized single-walled carbon nanotubes exhibit no deleterious effects in live cells or in vivo at concentrations needed for measurement. Via injecting a single-chirality carbon nanotube species responsive to lipids, we found that lipid accumulation in liver Kupffer cell lysosomes tracks the progression of non-alcoholic fatty-liver disease (NAFLD) in a live murine model. Notably, we found that that lipid accumulation is persistent in the Western Diet model of NAFLD after resuming normal feeding, suggesting long-term effects of a poor diet. This finding demonstrates that single-walled carbon nanotubes enable the development of new tools to allow biologists to measure disease states in situ.