Folic Acid-Conjugated 4-Amino-Phenylboronate, a Boron-Containing Compound Designed for Boron Neutron Capture Therapy, is an Unexpected Agonist for Human Neutrophils and Platelets

Boron neutron capture therapy (BNCT) is an anticancer treatment based on the accumulation in the tumor cells of B-10-containing molecules and subsequent irradiation with low-energy neutrons, which bring about the decay of B-10 to very toxic Li-7(3+) and He-4(2+) ions. The effectiveness of BNCT is limited by the low delivery and accumulation of the used B-10-containing compounds. Here, we report the development of folic acid-conjugated 4-amino-phenylboronate as a novel possible compound for the selective delivery of B-10 in BNCT. An extensive analysis about its biocompatibility to mature blood cells and platelet progenitors revealed that the compound markedly supports platelet aggregation, neutrophil oxidative burst, and inhibition of megakaryocyte development, while it does not have any manifest effect on red blood cells.