Image-guided thermal therapy with a dual-contrast magnetic nanoparticle formulation: A feasibility study

Abstract

Purpose/objective The aim of this study was to develop and investigate the properties of a magnetic iron oxide nanoparticle–ethiodised oil formulation for image-guided thermal therapy of liver cancer. Materials and methods The formulation comprises bionised nano-ferrite (BNF) nanoparticles suspended in ethiodised oil, emulsified with polysorbate 20 (BNF-lip). Nanoparticle size was measured via photon correlation spectroscopy and transmission electron microscopy. In vivo thermal therapy capability was tested in two groups of male Foxn1nu mice bearing subcutaneous HepG2 xenograft tumours. Group I (n =12) was used to screen conditions for group II (n =48). In group II, mice received one of BNF-lip (n =18), BNF alone (n =16), or PBS (n =14), followed by alternating magnetic field (AMF) hyperthermia, with either varied duration (15 or 20 min) or amplitude (0, 16, 20, or 24 kA/m). Image-guided fluoroscopic intra-arterial injection of BNF-lip was tested in New Zealand white rabbits (n =10), bearing liver VX2 tumours. The animals were subsequently imaged with CT and 3 T MRI, up to 7 days post-injection. The tumours were histopathologically evaluated for distribution of BNF-lip. Results The BNF showed larger aggregate diameters when suspended in BNF-lip, compared to clear solution. The BNF-lip formulation produced maximum tumour temperatures with AMF >20 kA/m and showed positive X-ray visibility and substantial shortening of T1 and T2 relaxation time, with sustained intratumoural retention up to 7 days post-injection. On pathology, intratumoural BNF-lip distribution correlated well with CT imaging of intratumoural BNF-lip distribution. Conclusion The BNF-lip formulation has favourable thermal and dual imaging capabilities for image-guided thermal therapy of liver cancer, suggesting further exploration for clinical applications.

Design and construction of a Maxwell-type induction coil for magnetic nanoparticle hyperthermia

“…Combining magnetic materials or magnetic fluids with low frequency (50-400 kHz) alternating magnetic fields (AMFs) to treat deep-seated tumors by focal heating has generated interest for several decades [1][2][3][4][5][6][7][8][9]. Magnetic fluid hyperthermia (MFH) received European Union approval in 2010 for human use in the treatment of glioblastoma [2].…”

“…Design of devices for biomedical applications employing low-frequency AMFs thus reduces to well-established engineering considerations for applicator or coil geometries to produce magnetic fields having desired flux density in a specified volume [10,[12][13][14][15]. Preclinical and clinical experiences with MFH using low-frequency AMFs have established its viability as a treatment for cancer [1][2][3][4][5][6][7][8]16,17].…”

“…Design considerations of the coil or inductor geometry must take into account the physics of energy transduction between a magnetic material and the potential for widespread tissue power deposition resulting from interactions with AMFs. Magnetic materials that have been most commonly used with low RF alternating fields in medicine include thermal seeds (small metallic bodies) and fluids containing magnetic nanoparticles, i.e., magnetic fluids or 'ferrofluid' [1,[3][4][5][6][7][8][16][17][18][19][20][21][22][23][24][25].…”

Synthesis of Ferrofluids Made of Iron Oxide Nanoflowers: Interplay between Carrier Fluid and Magnetic Properties

“…They are extremely versatile nanomaterials, showing both liquid and magnetic properties, with a huge potential in a large number of technological sectors, such as electric and thermal engineering, electronics, magneto-optics, catalysis, waste water treatment [ 1 , 2 , 3 , 4 , 5 ]. Moreover, ferrofluids have been attracting an increasing interest for biomedical applications since the magnetic nanoparticles may act as contrast media in magnetic resonance imaging, tags for magnetic biosensing, drug delivery carriers, magnetic hyperthermia agents for cancer therapy or/and thermally activated drug release [ 6 , 7 , 8 , 9 , 10 , 11 ]. The properties of the ferrofluids, and, hence, their field of application strictly depend on the features of the magnetic nanoparticles, such as the chemical composition (metallic ferromagnets and their oxides), the size, the shape and the crystallinity.…”

Thermal Therapy as Multidisciplinary Therapy Applied to Rectal Cancer:

“…In recently, there has been significant progress in the development and application of hyperthermia treatment planning software and non-invasive thermometry [40][41][42][43][44][45] .…”