Boron-Containing MOF Nanoparticles with Stable Metabolism in U87-MG Cells Combining Microdosimetry To Evaluate Relative Biological Effectiveness of Boron Neutron Capture Therapy

Abstract

Accurate prediction of the relative biological effectiveness (RBE) of boron neutron capture therapy (BNCT) is challenging. The therapy is different from other radiotherapy; the dynamic distribution of boron-containing compounds in tumor cells affects the therapeutic outcome considerably and hampers accurate measurement of the neutron-absorbed dose. Herein, we used boron-containing metal−organic framework nanoparticles (BMOFs) with high boron content to target U87-MG cells and maintain the concentration of the 10 B isotope in cells. The content of boron in the cells could maintain 90% (60 ppm) within 20 min compared with that at the beginning; therefore, the accurate RBE of BNCT can be acquired. The effects of BNCT upon cells after neutron irradiation were observed, and the neutron-absorbed dose was obtained by Monte Carlo simulations. The RBE of BMOFs was 6.78, which was 4.1-fold higher than that of a small-molecule boron-containing agent (boric acid). The energy spectrum of various particles was analyzed by Monte Carlo simulations, and the RBE was verified theoretically. Our results suggested that the use of nanoparticle-based boron carriers in BNCT may have many advantages and that maintaining a stable boron distribution within cells may significantly improve the efficiency of BNCT.

Boron-Containing Mesoporous Silica Nanoparticles with Effective Delivery and Targeting of Liver Cancer Cells for Boron Neutron Capture Therapy

“…These results indicated that modifying the SP94 peptide on nanoparticles could improve the targeting ability of tumor cells and realize the enrichment of 10 B in tumor cells to improve the therapeutic effect. Exposure to neutron irradiation can lead to changes in cell structure. , Obvious changes in the cell morphology after irradiation were observed (Figure f). We calculated the ratio of the long axis to the short axis of irradiated cells using ImageJ, and we found that the result of the SP94-LB@BA-MSN group was significantly different from the other groups, which means that this group had more changes in cell morphology (Figure S8).…”