PEG-Modified Carbon Nanotubesin Biomedicine: CurrentStatus and Challenges Ahead.

Since their discovery at the end of the previous millennium,carbonnanotubes (CNTs) have been the object of thousands of papers describingtheir applications in fields ranging from physics to electronics,photonics, chemistry, biology, and medicine. The development of chemicalapproaches to modify their graphitic sidewalls enabled the generationof poly(ethylene glycol) (PEG)-modified CNTs and their explorationin multiple biomedical applications. Studies at the cellular and organismlevel revealed that PEG-modified CNTs have favorable pharmacokineticand toxicology profiles. Recently, PEG-modified CNTs have been successfullytested in preclinical studies in the fields of oncology, neurology,vaccination, and imaging, suggesting that they are well suited forthe generation of novel multifunctional nanodrugs. Here we will reviewpublished data about the application of PEG-modified CNTs as in vitroand in vivotherapeutic and imagingtools and describe what is known about the interaction between PEG-modifiedCNTs and biological systems. Although several pieces of the puzzleare still missing, we will also attempt to formulate a preliminarystructure–function model for PEG-modified CNT cellular trafficking,disposition, and side effects. [ABSTRACT FROM AUTHOR]