Literature review. Experiences reported by our users

Experiment on DM100-INA

19 Jan Literature review. Experiences reported by our users

If you are considering getting instrumentation for magnetic heating of nPs, magnetic hyperthermia or magnetically controlled drug release, we encourage you to read on.

Heating nanoparticles using alternating magnetic fields has become increasingly more commercially relevant every year so in the spring of 2011 nB introduced the concept of the DM100 Series product to the scientific community; our intention was to learn from the scientist’s requirements and to make instrumentation that evolves with its users.

From the original DM1 applicator for calorimetry, and all the way down to the current catalog of the new D5 Series that enable calorimetry, local thermometry, thermal imaging, drug release, microscopy, atmosphere control, temperature control, thermalization, heartbeat control for in vivo experiments, multiple probing, etc, our products have proven nB’s commitment to quality, reliability and, above all, constant innovation.

Experiments using our instruments: DM100 & D5 Series

DM100 Series is a set of instruments, accessories and software tools that can be combined to form different configurations covering every kind of Magnetic Hyperthermia and Magnetic nanoHeating experimental setup. Each DM100 configuration is a complete workstation that allows you to automatically run complex tests, register data and analyse your results.

The new D5 Series is much more flexible and expandable because you can run different experiment just by changing CoilSet and Accessories without the need and complication of getting a new device. However, our DM100 Series systems had a modular concept. One controller could be used to drive multiple applicators –but not simultaneously.

In this document, we’ll briefly comment on a handful of scientific publications that users have shared with us which have been using DM100 instruments from last catalog of products, as well as some in-house applicators and accessories.

Nanomaterials characterization

The most popular study in magnetic heating of nanomaterials is the measurement of the SAR (Specific Absorption Rate), also known as SPA (Specific Power Absorption). This parameter represents the power dissipated by a sample when it is exposed to a given applied magnetic field. The samples studied are mainly magnetic colloids, usually water based (but can also be in organic or acid solvents). SAR is expressed in [W/g], and depends on concentration, solvent, field frequency, field intensity, field harmonic composition, aggregation for a given type of nanoparticle.  Composition of the nanoparticles as well as size and shape also affect SAR.

Most of publications dedicated to the study and report of SAR values of magnetic colloids indicate calorimetry as the method of choice. This method assumes that all the energy dissipated by the particles is finally transformed into heat which once dissipated across the sample’s liquid base solvent, induces a rise of temperature that can be measured. In conditions of perfect insulation, the dissipated heat energy can be easily calculated by means of the experiment duration, specific heat of the base liquid and the change in temperature of the colloid. The SAR/SPA of the particles will then be calculated from the colloidal concentration and the parameters of the field.

This procedure, although apparently simple, presents several challenges. In the initial years of scientific experimentation, the difficulty related to getting reliable, and particularly, repeatable results became evident as more and more papers were published. When nB designed the first applicator for calorimetry, we were already aware of the crucial role that the quality of the magnetic field instruments, measuring probes and thermal facilities played in accurate SAR determination.

The influence of particle size on SAR was studied and reported by Goya, Lima et al.1 in 2008 using the first version of DM1 developed in collaboration with the Institute of Nanoscience of Aragón. In 2009, González Fernández (from CSIC-Madrid) et al.2 reported their work on optimization of size, shape and magnetic properties for improving SAR. In 2011, Torres et al.3 presented their work with CoFe2O4 nanoparticles.

After the first commercial units were sold, in 2011 Sebastian et al.4 reported the magnetically-driven selective synthesis of Au clusters on Fe3O4 nanoparticles using DM1. The process allows growing gold selectively onto the heated magnetite surface, while keeping the synthesis solution comparatively cold.

Focused on core-shell type of particles, Zamora-Mora et al.5 characterized chitosan and iron oxide nanoparticles for magnetic hyperthermia. Chitosan is one of the most frequent materials in core-shell particles, and is under study as a biocompatible nanoparticle coating for hyperthermia, contrast agent and drug release.

Guardia et al.6 developed and published in 2014 a method for manufacturing an interesting kind of iron oxide nanocrystals with high SAR values with great potential for cancer therapy.

nB has collaborated actively with customers and leading researchers. Beatriz Sanz Sague, our lab specialist, has authored several papers in the hyperthermia research area framework. One of her latest works focuses on minimizing the impact of intracellular environments on heating efficiency obtaining the largest in vitro SPA values yet reported 7.

Another interesting example is the work leaded by Dr Seemann et al.8 on the properties of FePt core shell nPs, or her study of the long-term stability of colloids for magnetic heating, where nB’s product Magno was included and compared.

Clinic, biology and biochemistry

Our DM100 range of instruments is designed to fulfil the needs coming from every potential lab experiment regarding magnetic heating of nPs. In particular, DM2 and DM3 are focused on in vitro and in vivo procedures respectively. More than a dozen teams are already running preclinical procedures and biological validation using DM2 and DM3. Research groups have already published some promising data coming from the operation of these instruments.  Other researchers have managed to use DM1 for bio samples, like cells in suspension.

In 2011 and 2012, Marcos Campos et al.9 presented their results on hyperthermia tests on dendric cells. In 2012, Asín et al.10 unveiled some very interesting results showing cell death induced by magnetic heating of nanoparticles without noticeable temperature rise.

More recently, M. Criado et al.11 has tested the use of thermomagnetic polymer films as heating devices for magnetic hyperthermia resulting in an 85% reduction of cell viability obtaining promising new options for the treatment of small and superficial tumour lesions.

Beatriz Sanz et al.12 has used nB`s magnetic colloid Magno to study the cell toxicity comparing magnetic hyperthermia to exogenous heating showing a difference up to a maximum of 45% at 46ºC of temperature.

In the area of drug release, Hoare et al.13 developed a magnetically triggered composite membrane for on demand release, that was reported in 2009, and after optimization, in 2011. And in 2014, Carregal-Romero et al. 14 developed a microcapsule loaded with MnPs capable of releasing a molecular cargo. During this year, Cazares-Cortes et al.15 has worked with the release of anticancer drug doxorubicin from hybrid nanogels resulting in increasing twice the release applying an alternative magnetic field.

One original contribution to what today is being called Nano thermometry was made by Dias et al.16 when a method for using DNA as a molecular probe was presented in 2013. The group comparing calculations and thermal experiments with the data collected with DM1.

Functionalization is one of the most important areas of interest for researchers using magnetic heating of nanomaterials. From release to labelling or just biocompatibility, many papers have addressed this task to help save the gap between the pure magnetic material and the bio application. In 2014, Radovic et al.17 reported the in vivo evaluation of multifunctional Y-labeled MnPs for cancer applications.

Since the new D5 Series is relatively new, results coming from its users are yet to be published by the researchers.

This document was mainly written thanks to the collaboration and support of the authors of the cited works. Even when no protected content is shared here, the authors were kind to communicate to us about their activities and publications. Many of them are close collaborators of ours, sharing research projects and products development. We know that many other researchers in America, Europe and Asia are getting more and more data using our new D5 Series systems.

We are always pleased to know about what our instruments are being used for, so if you are one of our users and would like to share your experience with us we will be happy to feature your achievements in future editions of this review.



  1. Goya, Gerardo F., et al. “Magnetic Hyperthermia With Fe3 O4 Nanoparticles: The Influence of Particle Size on Energy Absorption.” IEEE Transactions on Magnetics 44.11 (2008): 4444-4447.
  2. Gonzalez-Fernandez, M. A., et al. “Magnetic nanoparticles for power absorption: Optimizing size, shape and magnetic properties.” Journal of Solid State Chemistry 182.10 (2009): 2779-2784.
  3. Torres, T. E., et al. “Magnetic properties and energy absorption of CoFe2O4 nanoparticles for magnetic hyperthermia.” Journal of Physics: Conference Series. Vol. 200. No. 7. IOP Publishing, 2010. 13. Hoare, Todd, et al. “A magnetically triggered composite membrane for on-demand drug delivery.” Nano letters 9.10 (2009): 3651-3657.
  4. Sebastian, Víctor, et al. “Magnetically-driven selective synthesis of Au clusters on Fe 3 O 4 nanoparticles.” Chemical Communications 49.7 (2013): 716-718.
  5. Zamora-Mora, Vanessa, et al. “Magnetic core–shell chitosan nanoparticles: Rheological characterization and hyperthermia application.” Carbohydrate polymers 102 (2014): 691-698.
  6. Guardia, Pablo, et al. “One pot synthesis of monodisperse water soluble iron oxide nanocrystals with high values of the specific absorption rate.” Journal of Materials Chemistry B2.28 (2014): 4426-4434.
  7. Sanz, Beatriz, et al. “Long‐Term Stability and Reproducibility of Magnetic Colloids Are Key Issues for Steady Values of Specific Power Absorption over Time.” European Journal of Inorganic Chemistry 2015.27 (2015): 4524-4531.
  8. Seemann, Klaus Michael, et al. “Magnetic heating properties and neutron activation of tungsten-oxide coated biocompatible FePt core–shell nanoparticles.” Journal of controlled release197 (2015): 131-137.
  9. Marcos-Campos, I., et al. “Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells.” Nanotechnology 22.20 (2011): 205101.
  10. Asín, L., et al. “Controlled Cell Death by Magnetic Hyperthermia: Effects of Exposure Time, Field Amplitude, and Nanoparticle Concentration.” Pharmaceutical Research, vol. 29, no. 5, 2012, pp. 1319–1327.
  11. Criado, Miryam, et al. “Magnetically responsive biopolymeric multilayer films for local hyperthermia.” Journal of Materials Chemistry B (2017).
  12. Sanz, Beatriz, et al. “Magnetic hyperthermia enhances cell toxicity with respect to exogenous heating.” Biomaterials 114 (2017): 62-70.
  13. Hoare, Todd, et al. “Magnetically triggered nanocomposite membranes: a versatile platform for triggered drug release.” Nano letters 11.3 (2011): 1395-1400.
  14. Carregal-Romero, Susana, et al. “Magnetically triggered release of molecular cargo from iron oxide nanoparticle loaded microcapsules.” Nanoscale 7.2 (2015): 570-576.
  15. Cazares-Cortes, Esther, et al. “Doxorubicin Intracellular Remote Release from Biocompatible Oligo (ethylene glycol) Methyl Ether Methacrylate-Based Magnetic Nanogels Triggered by Magnetic Hyperthermia.” ACS Applied Materials & Interfaces 9.31 (2017): 25775-25788.
  16. Dias, Jorge T., et al. “DNA as a molecular local thermal probe for the analysis of magnetic hyperthermia.” Angewandte Chemie International Edition 52.44 (2013): 11526-11529.
  17. Radović, Magdalena, et al. “Preparation and in vivo evaluation of multifunctional 90Y‐labeled magnetic nanoparticles designed for cancer therapy.” Journal of Biomedical Materials Research Part A 103.1 (2015): 126-134.
  18. Boskovic, M., et al. “Influence of size distribution and field amplitude on specific loss power.” Journal of Applied Physics117.10 (2015): 103903.
  19. Materia, Maria Elena, et al. “Mesoscale assemblies of iron oxide nanocubes as heat mediators and image contrast agents.” Langmuir 31.2 (2015): 808-816.
  20. Calatayud, M. Pilar, et al. “Cell damage produced by magnetic fluid hyperthermia on microglial BV2 cells.” Scientific Reports7.1 (2017): 8627.
  21. Bonvin, Debora, et al. “Tuning properties of iron oxide nanoparticles in aqueous synthesis without ligands to improve MRI relaxivity and SAR.” Nanomaterials 7.8 (2017): 225.
  22. Orsini, N. Jović, et al. “Magnetic and Power Absorption Measurements on Iron Oxide Nanoparticles Synthesized by Thermal Decomposition of Fe (acac) 3.” Journal of Magnetism and Magnetic Materials (2017).
  23. Sanz, Beatriz, et al. “In silico before in vivo: how to predict the heating efficiency of magnetic nanoparticles within the intracellular space.” Scientific reports 6 (2016).
  24. Casula, Maria F., et al. “Manganese doped-iron oxide nanoparticle clusters and their potential as agents for magnetic resonance imaging and hyperthermia.” Physical Chemistry Chemical Physics 18.25 (2016): 16848-16855.
  25. Hai, J., et al. “Maghemite nanoparticles coated with human serum albumin: combining targeting by the iron-acquisition pathway and potential in photothermal therapies.” Journal of Materials Chemistry B 5.17 (2017): 3154-3162.
  26. Mazario, Eva, et al. “Design and Characterization of Iron Oxide Nanoparticles Functionalized with HSA Protein for Thermal Therapy.” IEEE Transactions on Magnetics (2017).
  27. Mazuel, François, et al. “Magneto‐Thermal Metrics Can Mirror the Long‐Term Intracellular Fate of Magneto‐Plasmonic Nanohybrids and Reveal the Remarkable Shielding Effect of Gold.” Advanced Functional Materials 27.9 (2017).
  28. Soares, Paula IP, et al. “Thermal and magnetic properties of iron oxide colloids: influence of surfactants.” Nanotechnology26.42 (2015): 425704.