Boron neutron capture therapy (BNCT) is one of the most appealing radiotherapy modalities, whose localization can be further improved by the employment of boron-containing nanoformulations, but the fabrication of biologically friendly, water-dispersible nanoparticles (NPs) with high boron content and favorable physicochemical characteristics still presents a great challenge. Here, we explore the use of elemental boron (B) NPs (BNPs) fabricated using the methods of pulsed laser ablation in liquids as sensitizers of BNCT. Depending on the conditions of laser-ablative synthesis, the used NPs were amorphous (a-BNPs) or partially crystallized (pc-BNPs) with a mean size of 20 nm or 50 nm, respectively. Both types of BNPs were functionalized with polyethylene glycol polymer to improve colloidal stability and biocompatibility. The NPs did not initiate any toxicity effects up to concentrations of 500 µg/mL, based on the results of MTT and clonogenic assay tests. The cells with BNPs incubated at a ¹⁰B concentration of 40 µg/mL were then irradiated with a thermal neutron beam for 30 min. We found that the presence of BNPs led to a radical enhancement in cancer cell death, namely a drop in colony forming capacity of SW-620 cells down to 12.6% and 1.6% for a-BNPs and pc-BNPs, respectively, while the relevant colony-forming capacity for U87 cells dropped down to 17%. The effect of cell irradiation by neutron beam uniquely was negligible under these conditions. Finally, to estimate the dose and regimes of irradiation for future BNCT in vivo tests, we studied the biodistribution of boron under intratumoral administration of BNPs in immunodeficient SCID mice and recorded excellent retention of boron in tumors. The obtained data unambiguously evidenced the effect of a neutron therapy enhancement, which can be attributed to efficient BNP-mediated generation of α-particles.

The technique of laser ablation in liquids is applied to produce Boron-containing nanoparticles from ablation of a Fe ₂ B bulk target enriched in ¹⁰ B isotope. Laser ablation of the target in liquid isopropanol results in partial disproportionation to free Fe and Boron while nanoparticles of Fe ₂ B are also presented. The nanoparticles are magnetic and can be collected using a permanent magnet. The average size of nanoparticles is about 15 nm. The content of ¹⁰ B in the generated nanoparticles amounts to 76.9%. The nanoparticles are biocompatible and can be used in boron neutron capture therapy.

In this work, we investigated the effect of photoconversion covers based on ruby (chromium-doped alumina (Al₂O₃:Cr³⁺)) particles (PCC-R) on the growth and development of lettuce (Lactuca sativa) plants. Ruby particles (from 100 nm to 2 μm) were obtained by the sequential application of spall laser ablation and further laser fragmentation. The content of chromium ions relative to aluminum ions in the nanoparticles was 3.3 × 10⁻³. The covers with different densities of applied ruby particles (2 × 10⁷ m⁻² (PCC-R7), 2 × 10⁸ m⁻² (PCC-R8), 2 × 10⁹ m⁻² (PCC-R9)) were studied in the present work. The PCC-Rs had two wide bands of luminescence excitation. The first one was from 350 nm to 450 nm with a maximum at 405 nm, and the second one was from 500 nm to 600 nm with a peak at 550 nm. Synthesized covers emitted in the range of 650 nm to 750 nm, with a peak at 695 nm. It has been shown that PCC-R8, in contrast to PCC-R7 and PCC-R9, provided an increase in yield by 40% and was characterized by increased water use efficiency during dark respiration and assimilation of carbon dioxide in plants. It is assumed that the observed positive effect of PCC-R8 photoconversion covers is associated with the activation of regulatory mechanisms due to a qualitative change in the light spectrum.

Optimization of laser synthesis regimes producing colloidal solutions of boron nanoparticles for their application as a promising boron-containing agent of

In this paper, temperature distribution in the diffusion flame during combustion of isopropanol or isopropanol with addition of boron nanoparticles in the amount of 0.5 wt % in oxygen was studied experimentally by using coherent anti-Stokes Raman scattering (CARS) spectroscopy. The addition of boron was found to result in an increase in temperature in the flame front by 150 K.

Ruby grains are synthesized by laser heating of the dry mixture of Al₂O₃ and Cr₂O₃ in air. Quasi-continuous radiation of a Nd:YAG laser was used for this purpose with an average power of 15 W. The synthesized ruby was characterized by x-ray diffractometry. Ruby grains demonstrate strong photo-luminescence in the vicinity of 700 nm. Ruby particles were further fragmented to smaller particles using the technique of laser fragmentation in liquids and integrated into a polymer matrix. A luminescence map acquired with the help of a photo-fluorimeter confirms efficient photo-conversion of green-blue radiation of the synthesized ruby into the red region.