nanoTherics Ltd.

We describe the design and application of a new apparatus for applying Radiofrequency (RF) electromagnetic fields to cells in culture on a microscope stage. This new design enables real-time studies of the actuation of magnetic nanoparticles bound to membrane receptors or internalised within cells together with the study of magnetic fluid hyperthermia (MFH)-associated effects.

RF coils were fabricated and electromagnetic simulations were performed along with compatibility evaluations and calorimetric experiments using this apparatus at discreet frequencies between 100 kHz and 1 MHz. Cell killing via MFH was investigated in a neuroblastoma tumour cell line.

Simulations and evaluations showed that the field intensity and homogeneity experienced by the cells within the chamber is best with a planar coil configuration. The incubation chamber was suitable for cell culture and the design was compatible with mountings on different makes of microscopes as it mimics a standard 96/24/6 tissue-culture well plate. Successful calorimetric and MFH cytotoxicity proof-of-principle experiments were performed and are presented.

We conclude from these experiments that alternating magnetic field (AMF)-mediated activation and magnetic fluid hyperthermia (MFH) research will benefit from this RF coil that fits inside an incubation chamber, mounted onto a microscope. This new design could be used to assist real-time MFH studies in vitro.

To examine the potential of magnetic nanoparticles (MNPs) in transfecting human osteosarcoma fibroblasts (MG-63) and investigate the effects of a novel non-viral oscillating nanomagnetic gene transfection system (magnefect-nano™) in enhancing transfection efficiency (TE).

MG-63 cells were transfected using MNPs coupled with a GFP-carrying plasmid. The magnefect-nano system was evaluated for transfection efficiency and potential associated effects on cell viability.

MG-63 cells were efficiently transfected using MNPs and the magnefect-nano system significantly enhanced overall transfection efficiency. MNPs were not found to affect cell viability and/or function of the cells.

Non-viral transfection using MNPs and the magnefect-nano system can be used to transfect MG-63 cells and assist reporter gene delivery on a single cell basis, highlighting the wide potential of nanomagnetic gene transfection in gene therapy.

non-viral magnetic nanoparticle-based transfection was evaluated using both static and oscillating magnet arrays.

Fluorescence intensity (firefly luciferase) of transfected H292 cells showed no increase using a 96-well NdFeB magnet array when the magnets were 5 mm from the cell culture plate or nearer. At 6 mm and higher, fluorescence intensity decreased systematically.

In all cases, fluorescence intensity was higher when using an oscillating array compared to a static array. For distances closer than 5 mm, the oscillating system also outperformed Lipofectamine 2000™.