Biocompatibility of functionalized boron phosphate (BPO4) nanoparticles for boron neutron capture therapy (BNCT) application

Boron neutron capture therapy (BNCT) is a radiotherapy treatment based on the accumulation in the tumor of a 10B-containing drug and subsequent irradiation with low energy neutrons, which bring about the decay of 10B to 7Li and an α particle, causing the death of the neoplastic cell. The effectiveness of BNCT is limited by the low delivery and accumulation of the used boron-containing compounds. Here we report the development and the characterization of BPO4 nanoparticles (NPs) as a novel possible alternative drug for BNCT. An extensive analysis of BPO4 NP biocompatibility was performed using both mature blood cells (erythrocytes, neutrophils and platelets) and a model of hematopoietic progenitor cells. A time- and concentration-dependent cytotoxicity study was performed on neoplastic coloncarcinoma and osteosarcoma cell lines. BPO4 functionalization with folic acid, introduced to improve the uptake by tumor cells, appeared to effectively limit the unwanted effects of NPs on the analyzed blood components.From the Clinical EditorBoron neutron capture therapy (BNCT) is a radiotherapy treatment modality based on the accumulation of a 10B-containing drug and subsequent irradiation with low energy neutrons, inducing the decay of 10B to 7Li and an α particle, causing neoplastic cell death. This team of authors reports on a folic acid functionalized BPO4 nanoparticle with improved characteristics compared with conventional BNCT approaches, as demonstrated in tumor cell lines, and hopefully to be followed by translational human studies.

Graphical AbstractThe development of BPO4 nanoparticles as a possible 10B-carrier for Boron Neutron Capture Therapy is reported here. BPO4 nanoparticles were also functionalized with folic acid to explore the cellular uptake route mediated by receptor-mediated endocytosis of folic acid, which is especially active in tumour cells. An extensive chemical characterization of bare and functionalized BPO4 nanoparticles was performed, followed by the analysis of biocompatibility towards blood cells, hematopoietic progenitor cells, and neoplastic cell lines. Although bare NPs displayed some unwanted effects on the studied cells, functionalization with folic acid effectively limited this cytotoxicity.Figure optionsDownload high-quality image (146 K)Download as PowerPoint slide