OVERVIEW ON THE MAJOR RESEARCH ACTIVITIES ON CARBON NANOTUBES BEING DONE IN AMERICA, EUROPE AND ASIA - Carbon Nanotubes: From Bench Chemistry to Promising Biomedical Applications - page 258

targeted CNTs and a better spatial resolution in comparison with conventional
optical techniques. 67
The successful application of functionalised CNTs, for the delivery of
otherwise toxic or insoluble drugs, has encouraged the exploitation of
additional procedures. Among them, it is worth mentioning the use of
SWCNTs as carrier of Pt-based pro-drugs: 68 in this study, a Pt(IV) complex,
containing folic acid (FA) as targeting agent at an axial position, was attached
to the free amino groups of the SWCNT-PL-PEG adduct (Fig. 9.11). As regards
the mechanism involved, the SWCNTs were shown to have been taken into
cancer cells by endocytosis, while the entrapment of the SWCNTs within the
endosomes was conirmed by luorescence microscopy of SWCNTs. 69 Once
selectively inside cancer cells, which tend to overexpress the target folic
receptor (FR), the reducing environment converted the pro-drug into Pt(II)
derivative, which subsequently translocated into the nucleus and interacted
with the DNA. These results conirmed the ability of CNT-Pt conjugates to
trigger speciic destruction of cancer cells.
Figure 9.11 Cancer cell uptake of SWCNT-Pt(IV)-FA complexes and subsequent
reduction and release of Pt(II) derivative into the nuclear DNA. Figure modiied from
Dhar et al . 68 with permission. See also Colour Insert.
Apart from drug delivery, the research group has also been involved in
gene transfection of small interfering RNA (siRNA). 70 It has been already
reported that the delivery of siRNA to human T cells to silence the expression
of the human immunodeiciency virus (HIV) speciic cell surface receptors