Boron-doped nanodiamonds as possible agents for local hyperthermia

Abstract

In this work, the effective heating of surrounding water by heavily-boron-doped nanodiamonds (NDs) under laser irradiation of visible wavelength was found. Using Raman scattering spectroscopy of aqueous suspensions of boron-doped NDs, it was found that this abnormally high heating results in the weakening of hydrogen bonds much more so (2-5 times stronger) than for undoped NDs. The property of boron-doped NDs to heat a solvent under the influence of laser radiation (1-5 W cm −2 ) opens broad prospects for their use to create nanoagents for medical oncology and local hyperthermia.

Boron-Doped Nanodiamonds as Anticancer Agents: En Route to Hyperthermia/Thermoablation Therapy

“…The surface of all BDNDs was cleaned by boiling nanoparticles in a mixture of sulfuric and nitric acids in the ratio 3:1 at a temperature of 200 °C for 17 h. The result of this kind of cleaning is a surface coated with −COOH groups. 11 Furthermore, the samples were purified from acids during 3−4 cycles of washing with water and subsequent centrifugation at 27 530 g for 30 min (Sigma 3-18KS centrifuge). Purification from acids ended when the BDND was stopped to precipitate.…”

“…9,10 In the result of the study of aqueous suspensions of these BDNDs, it was found that doping of nanodiamonds with boron gives them the ability to substantially heat their environment under the laser irradiation. 11 This opens up the possibility of using BDNDs as hyperthermia agents.…”

“…Nanodiamonds (NDs) are the most promising nanomaterials for use in biomedicine due to the unique combination of their properties; NDs are biocompatible, have a low toxicity, are mechanically and chemically stable, can have stable photoluminescence, and have a multifunctional, easily modifiable surface, etc. − Due to their surfaces, NDs are one of the best candidates for the role of the basis of bioconjugates, drug carriers, and adsorbents of harmful substances. , Doping a diamond lattice with impurity atoms can give it interesting new properties. The most famous doping results are N–V or Si–V color centers, which produce the bright photoluminescence of NDs. − Doping a diamond lattice with boron provides significant electroconductive properties up to superconductivity. , However, the reduction of boron-doped diamonds to nanoscale sizes is a difficult task that was successfully resolved only in 2015; using HPHT “bottom-up” synthesis from the organoboron precursor, we have synthesized boron-doped nanodiamonds (BDNDs) with a size of less than 10 nm. , In the result of the study of aqueous suspensions of these BDNDs, it was found that doping of nanodiamonds with boron gives them the ability to substantially heat their environment under the laser irradiation . This opens up the possibility of using BDNDs as hyperthermia agents.…”

“…This approach ensures a local targeted “inside-out” hyperthermia of the tumors, which can be easily combined with the use of nanoparticles as drug carriers. The source of the energy for heating nanoparticles is either an alternating magnetic field (for ferromagnetic nanoparticles , ) or laser radiation (for metal nanoparticles, , carbon nanotubes (CNTs), nanocomplexes based on them, , and recently proposed boron-doped nanodiamonds , ). For all types of nanoparticles, ferromagnetic, metal, CNT, and BDND (in this study), the possibility of heating the environment by tens of Celsius degrees has been shown.…”

Top-down fabrication of high-uniformity nanodiamonds by self-assembled block copolymer masks

“…This method can be applied to bulk diamond, diamond with tailored dopant properties, or isotopically purified diamond to produce NDs with the same dimensional properties 41,42 . Doped NDs are attractive materials for the study of medical oncology 43 , electrochemistry 44,45 , diamond electronics 46 , and superconductivity 47,48 . Diamond enriched with 12 C can enable increased coherence times of hosted spin systems due to the limited number of interfering spin impurities in the host material 42 .…”