Water-soluble BODIPY-nido-carborane nanoparticles applied to biocompatibility tumor cell imaging

In this article, o-carborane has a high boron content, high hydrophobicity, and good chemical stability. It has been widely used in the fields of biology and medicine, especially in the application of boron neutron capture therapy (BNCT). However, o-carborane is a fat-soluble compound, its hydrophobicity is too strong, and its bioavailability is poor. This project aims to improve the water solubility of o-carborane drugs, so that the drugs can reach specific sites. For this reason, this article provides a one-pot reaction for the synthesis of water-soluble boron-containing drugs. 2-Chloro-1-(difluoroboranyl)-5-((4-ethyl-3,5-dimethyl-2H-pyrrol-2-ylidene)(phenyl) methyl)-1H-pyrrole and ethylenediamine are used as raw materials to synthesize fluorescent molecular probe BODIPY-NH₂, and the fluorescent molecular probe is reacted with P-CBMA (poly(carboxybetaine methacrylate)) to produce a water-soluble gel polymer. Water-soluble o-carborane polymers were synthesized by hydrogen bonding of the polymers with bis(4-azaspiro[3.4]octan-4-ium)-nido-ortho-carborane and bis(5-azaspiro[4.5]decan-5-ium)-nido-ortho-caborane. The two polymers were characterized and the results showed that the maximum UV absorption wavelength of the two boron polymers in different polar solutions was 530-540 nm. In the fluorescence spectrum, the maximum emission wavelengths of the two boron polymers are concentrated between 550 and 560 nm. Through electron microscopy imaging, the fluoroboron pyrrole polymers wrap the boron clusters to form a spherical stacked. Through fluorescent cell imaging, both boron polymers can enter target cells.