Substituted Carborane-Appended Water-Soluble Single-Wall Carbon Nanotubes:  New Approach to Boron Neutron Capture Therapy Drug Delivery

Abstract

Substituted C(2)B(10) carborane cages have been successfully attached to the side walls of single-wall carbon nanotubes (SWCNTs) via nitrene cycloaddition. The decapitations of these C(2)B(10) carborane cages, with the appended SWCNTs intact, were accomplished by the reaction with sodium hydroxide in refluxing ethanol. During base reflux, the three-membered ring formed by the nitrene and SWCNT was opened to produce water-soluble SWCNTs in which the side walls are functionalized by both substituted nido-C(2)B(9) carborane units and ethoxide moieties. All new compounds are characterized by EA, SEM, TEM, UV, NMR, and IR spectra and chemical analyses. Selected tissue distribution studies on one of these nanotubes, {([Na(+)][1-Me-2-((CH(2))(4)NH-)-1,2-C(2)B(9)H(10)][OEt])(n)(SWCNT)} (Va), show that the boron atoms are concentrated more in tumors cells than in blood and other organs, making it an attractive nanovehicle for the delivery of boron to tumor cells for an effective boron neutron capture therapy in the treatment of cancer.

Delivery of drugs and biomolecules using carbon nanotubes

“…on external walls); (b) defect functionalization at the opened tips and sidewalls of CNT; (c) covalent functionalization (also outside CNT on their sidewalls); and, (d) encapsulation of bioactive molecules or drugs inside CNT. The most common method for non-covalent modification is to absorb functional moieties containing aromatic groups onto the external wall of CNT through p-p interactions [39][40][41][42]. As an example, C 2 B 10 carborane cages are attached to SWCNT side walls via nitrene cycloaddition, and their suitability for transporting large and heavy groups into the cells without any toxicity is evaluated [43].…”

Folate and iron difunctionalized multiwall carbon nanotubes as dual-targeted drug nanocarrier to cancer cells

“…Pantarotto et al explored the delivery of bioactive peptides of K(FITC)QRMHLRQYELLC into 3T3 cells [12], methotrexate into Jurkat cells [13] and plasmid DNA into HeLa cells [14], using f-CNTs as non-targeted drug carriers. Additionally, f-CNTs have been applied as the non-targeted drug carriers to transport platinum(IV) [15], oligodeoxynucleotides [16] and boron [17] into cancer cells. Although great improvements have been made to the application of f-CNTs as drug carriers, there are two major obstacles blocking further use of the f-CNTs in cancer chemotherapy.…”

Carbon Nanotubes: Potential Benefits and Risks of Nanotechnology in Nuclear Medicine

“…The mechanism by which this occurs is not well understood, but it may be mediated by endocytosis (9) or direct insertion of the nanotubes (i.e., as ''microneedles'') through cell membranes (10). Therefore, CNTs have been studied for intracellular delivery of proteins and peptides (10-12), drugs (13)(14)(15), MRI or fluorescence contrast agents (16,17), and DNA (18) as well as for vaccine development (19).…”