Biocompatible Iron–Boron Nanoparticles Designed for Neutron Capture Therapy Guided by Magnetic Resonance Imaging

Abstract

The combination of multiple functions in a single nanoparticle (NP) represents a key advantage of nanomedicine compared to traditional medical approaches. This is well represented by radiotherapy in which the dose of ionizing radiation should be calibrated on sensitizers biodistribution. Ideally, this is possible when the drug acts both as radiation enhancer and imaging contrast agent. Here, an easy, one‐step, laser‐assisted synthetic procedure is used to generate iron–boron (Fe–B) NPs featuring the set of functions required to assist neutron capture therapy (NCT) with magnetic resonance imaging. The Fe–B NPs exceed by three orders of magnitude the payload of boron isotopes contained in clinical sensitizers. The Fe–B NPs have magnetic properties of interest also for magnetophoretic accumulation in tissues and magnetic hyperthermia to assist drug permeation in tissues. Besides, Fe–B NPs are biocompatible and undergo slow degradation in the lysosomal environment that facilitates in vivo clearance through the liver–spleen–kidneys pathway. Overall, the Fe–B NPs represent a new promising tool for future exploitation in magnetic resonance imaging‐guided boron NCT at higher levels of efficacy and tolerability.

The Pharmaceutical Technology Approach on Imaging Innovations from Italian Research

“…A possible way to obtain multifunctional NPs is represented by bi-metallic NPs. In this context, Torresan et al [ 41 ] developed, by an easy, one-step, laser-assisted synthetic procedure, iron–boron (Fe–B) NPs coated with a shell of polyvinylpyrrolidone. The obtained NPs, exhibiting an average diameter of 26 ± 15 nm as measured by dynamic light scattering (DLS), featured the functions required for both neutron capture therapy (NCT) and MRI.…”

Importance of radiobiological studies for the advancement of boron neutron capture therapy (BNCT)

“…In this sense, huge efforts are devoted to the development of new theranostic compounds for BNCT (e.g. Refs 25,26,35,38,39). One example is the halogenated (most of them iodinated) carborane derivatives that were shown to provide nuclear imaging by PET-CT (positron emission tomography-computed tomography, 124 I-, a positron emitter) and SPECT (single photon emission computed tomography, 125 I-, a gamma emitter) (Refs [40][41][42].…”

“…), nanoparticles (e.g. Refs25, 26), boron cluster agents, carrier proteins conjugated with boron compounds (e.g. Refs27, 28) and bimodal drugs (with anti-tumoural and BNCT effects) such as metallocarboranes (e.g.…”

Laser-ablative aqueous synthesis and characterization of elemental boron nanoparticles for biomedical applications

“…In particular, we previously showed that techniques of femtosecond laser ablation and fragmentation can be used to fabricate stable solutions of low-size dispersed NPs of a variety of materials, including Au 28 , 31 , Si 32 , 34 , TiN 33 , 35 , elemental Bi 36 NPs. Recently, methods of laser ablation from a Fe-B alloy target were elaborated for the fabrication of composite Fe-B NPs 37 . The experiments were carried out in acetone in the presence of ligands (polyvinyl pyrrolidone, PVP) to control size characteristics and minimize oxidation effects, which could alter material stoichiometry.…”