Boron-Rich Boron Carbide Nanoparticles as a Carrier in Boron Neutron Capture Therapy: Their Influence on Tumor and Immune Phagocytic Cells

Abstract

The aim of the work was to study the interaction between boron-rich boron carbide nanoparticles and selected tumor and immune phagocytic cells. Experiments were performed to investigate the feasibility of the application of boron carbide nanoparticles as a boron carrier in boron neutron capture therapy. Boron carbide powder was prepared by the direct reaction between boron and soot using the transport of reagents through the gas phase. The powder was ground, and a population of nanoparticles with an average particle size about 80 nm was selected by centrifugation. The aqueous suspension of the nanoparticles was functionalized with human immunoglobulins or FITC-labeled human immunoglobulins and was then added to the MC38 murine colon carcinoma and to the RAW 264.7 cell line of mouse macrophages. Flow cytometry analysis was used to determine interactions between the functionalized boron carbide nanoparticles and respective cells. It was shown that B4C–IgG nanoconjugates may bind to phagocytic cells to be internalized by them, at least partially, whereas such nanoconjugates can only slightly interact with molecules on the cancer cells’ surface.

Macrophages as carriers of boron carbide nanoparticles dedicated to boron neutron capture therapy

“…These results suggest that to obtain effective cellular carriers, not only the selection of concentrations but also exposure time is crucial. Therefore in our previous studies, the uptake of boron carbide nanoparticles by RAW264.7 macrophages was confirmed by flow cytometry and fluorescence microscopy after 4 and 24 h of exposure [ 25 ]. Herein, we additionally observed an increase in cell granularity based on SSC in a flow cytometer (Fig.…”

BPA‐Containing Polydopamine Nanoparticles for Boron Neutron Capture Therapy in a U87 Glioma Orthotopic Model

“…Although our results, based on a limited record, suggest that this strategy has achieved the desired outcome, there are still some problems with B‐PDA nanoparticles. Compared with the previous B‐10 enriched nanoparticles, [ 38–44 ] our nanoparticles have a lower boron content, which led to more particles being injected to meet the demand of BNCT. Moreover, the metabolism, degradation and clearance performance of B‐PDA nanoparticles were still determined, and the nanoparticle size was over 100 nm.…”

Polymer-Stabilized Elemental Boron Nanoparticles for Boron Neutron Capture Therapy: Initial Irradiation Experiments

“…The use of nanoparticles of this type with such a stabilizing agent had several goals. First of all, we aimed at showing the possibility of creating nanoparticles from elemental boron without impurities, bypassing complex multi-step chemical reactions, which is an advantage over previously known methods of creating boron nitride and boron carbide nanoparticles [27,[31][32][33][34][35]. If only boron ( 10 B) is used, its entire mass can be involved in the neutron capture reaction, which is critical for BNCT.…”

“…Delivering more boron to tumor cells can be solved using boron nanoparticles, which can carry thousands of boron atoms per particle and sequester in tumor cells longer due to differences in accumulation mechanisms [27][28][29][30]. The synthesis of boron nitride and boron carbide nanoparticles in related biological experiments has been reported [27,[31][32][33][34][35]; however, these nanoparticles contain a significant amount of nitrogen or carbon that do not participate in neutron capture reactions. Borophenes have also been proposed as carriers of large amounts of boron atoms for BNCT [36], and, compared to boron nitride and boron carbide nanoparticles, they do not contain additional non-capture elements.…”