| Due to their unique physical properties, single-walled carbon nanotubes (SWCNTs) have become increasingly important in applications as diverse as biosensors and building blocks for nano-electronics. SWCNTs are considered to be effective drug and gene carriers because they have the ability to either directly penetrate or be endocytosed into cells with relatively low or no toxicity. However, there is a limitation: in order to be used as drug or gene carriers, SWCNTs must be dispersed in aqueous solution. In fact, studies have shown that an aggregated form of SWCNTs induces a toxic response in vivo, thus limiting their use as delivery tools. This toxic response, consisting of aggregate accumulation in the lung and spleen and consequent inflammation and fibrosis, motivated us to study strategies for achieving effective SWCNT dispersion in aqueous solution. We investigated the mechanisms of SWCNT dispersion and aggregation and how certain SWCNT aggregates can be re-dispersed by addition of chelating or reducing agents. We also developed a method to re-disperse SWCNT aggregates by using enzymes, which has the potential to control the aggregation status of SWCNTs in solution. Our studies and findings can advance the development of SWCNTs for future applications in drug/DNA delivery. |
