Increased Heating Efficiency and Selective Thermal Ablation of Malignant Tissue with DNA-Encased Multiwalled Carbon Nanotubes

Abstract

Nanoparticles, including multiwalled carbon nanotubes (MWNTs), strongly absorb near-infrared (nIR) radiation and efficiently convert absorbed energy to released heat which can be used for localized hyperthermia applications. We demonstrate for the first time that DNA-encasement increases heat emission following nIR irradiation of MWNTs, and DNA-encased MWNTs can be used to safely eradicate a tumor mass in vivo. Upon irradiation of DNA-encased MWNTs, heat is generated with a linear dependence on irradiation time and laser power. DNA-encasement resulted in a 3-fold reduction in the concentration of MWNTs required to impart a 10 °C temperature increase in bulk solution temperature. A single treatment consisting of intratumoral injection of MWNTs (100 μL of a 500 μg/mL solution) followed by laser irradiation at 1064 nm, 2.5 W/cm2 completely eradicated PC3 xenograft tumors in 8/8 (100%) of nude mice. Tumors that received only MWNT injection or laser irradiation showed growth rates indistinguishable from nontreated control tumors. Nonmalignant tissues displayed no long-term damage from treatment. The results demonstrate that DNA-encased MWNTs are more efficient at converting nIR irradiation into heat compared to nonencased MWNTs and that DNA-encased MWNTs can be used safely and effectively for the selective thermal ablation of malignant tissue in vivo.

Endohedral confinement of a DNA dodecamer onto pristine carbon nanotubes and the stability of the canonical B form

“…This lateral opening of the chain, resulting in an encapsulation anisotropy of ∆ϕ max =16.5º, is clearly a reversible process because d(Ψ 12 , Ψ 13 ) falls back to the purely crystalline B-DNA values during the observed time window. The two symmetrical shoulders located at regions defined by nucleotide indices (20)(21)(22) and (8)(9)(10), evidencing a slight distance decrease between contacts, need to be carefully analysed. is performed for the maximum number of allowed H-bonds for a particular donor-acceptor pair.…”

“…Because the DNA had been artificially inserted, no information about the encapsulation process itself, e.g., its thermodynamical spontaneity and kinetics, was provided. Previous experiments and calculations indicate that the biomolecule can be confined onto D = 2.7 nm SWCNTs 13 and D = 3-4 nm multi-walled carbon nanotubes (MWCNTs) 20,21 , however, the corresponding working temperatures (350 -400K) were far too high to have any physiological relevance. Furthermore, the experimental observations of Iijima et al indicated that encapsulation of DNA onto MWCNTs was a competing mechanism with wrapping of the biomolecule around the external wall 20 ; their reported data failed to identify the relevant conditions upon which the confinement process is favoured, such as ionic strength of the media and temperature.…”

State of Art on Bioimaging by Nanoparticles in Hyperthermia and Thermometry: Visualization of Tissue Protein Targeting

“…Another approach is direct injection of antibody bound nanoparticles at the tumor site with a high degree of specificity with minimum effect on healthy tissues [50,51]. The in vivo therapeutic utility of nanoparticles is growing based on energy utilization from different sources of magnetic fields, microwaves, lasers and ultrasound to the tumor tissue [52][53][54].…”

Photothermal Effect of PEG-Functionalized Single-Walled Carbon Nanotubes

“…Most of the studies involving SWNTs or other nanoparticles-assisted photothermal treatment were based on high laser power density of 1-40 W/cm 2 [23][24][25][26][27][28]. However, high laser power density could cause non-selective photothermal damage to the surrounding normal tissues.…”