Imaging the distribution of individual platinum-based anticancer drug molecules attached to single-wall carbon nanotubes.
OBJECTIVE
To image the distribution of drug molecules attached to single-wall carbon nanotubes (SWNTs).


METHODS
Herein we report the use of scanning transmission electron microscopy (STEM) for atomic scale visualization and quantitation of single platinum-based drug molecules attached to SWNTs designed for targeted drug delivery. Fourier transform infrared spectroscopy and energy-dispersive x-ray spectroscopy were used for characterization of the SWNT drug conjugates.


RESULTS
Z-contrast STEM imaging enabled visualization of the first-line anticancer drug cisplatin on the nanotubes at single molecule level. The identity and presence of cisplatin on the nanotubes was confirmed using energy-dispersive x-ray spectroscopy and Fourier transform infrared spectroscopy. STEM tomography was also used to provide additional insights concerning the nanotube conjugates. Finally, our observations provide a rationale for exploring the use of SWNT bioconjugates to selectively target and kill squamous cancer cells.


CONCLUSIONS
Z-contrast STEM imaging provides a means for direct visualization of heavy metal containing molecules (i.e., cisplatin) attached to surfaces of carbon SWNTs along with distribution and quantitation.
University of Connecticut, Storrs, CT 06269, USA.
Ashwin A
AA
Bhirde
Alioscka A
AA
Sousa
Vyomesh
V
Patel
Afrouz A
AA
Azari
J Silvio
JS
Gutkind
Richard D
RD
Leapman
James F
JF
Rusling
D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism*; D045744:Cell Line, Tumor; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D017348:Microscopy, Electron, Scanning Transmission; D008954:Models, Biological; D050997:Nanomedicine / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared
D000970:Antineoplastic Agents; D037742:Nanotubes, Carbon; D010984:Platinum