For magnetic hypermedia therapy different materials have been studied in literature. The question is that, which nanoparticles are the most appropriate candidates for hypothermia therapy. May be the first answer is iron oxide(Fe3o4&gammaFe2O3) nanoparticles. but why? If the only reason for this answer is the nontoxic nature of these nanoparticles? Or there are other reasons?
Biocompatibility of the particles is a core issue in the clinical application of magnetic hyperthermia. Most research sticks to iron oxide particles not only because they have proven biocompatibility, but because iron oxide nanoparticles have already been approved for biomedical use both in the US and the EU, setting a precedent for future applications. Nanoparticles made by other materials, even if proven to be biocompatible in in vitro and animal models, would take a long time to transfer into human studies, slowing down the real clinical application of magnetic hyperthermia.
From the purely physical point of view, the heating ability of the particles is a function of the saturation magnetization, anisotropy constant, size of the particle and the temperature, as well as the applied magnetic field. Different materials will have different optimal sizes for maximum heating ability at room temperature, and this is an issue that has to be considered also for in vivo applications: big magnetic particles are usually not colloidal stable and are not able to cross biological barriers. But for a given material, the smaller the particle, the lower the heating ability. All you can aim is to find a compromise between the optimal "physical" and "biological" properties of the particles. You can find an excellent survey on the physics of magnetic hyperthermia in
Carrey et al. 2011
http://scitation.aip.org/content/aip/journal/jap/109/8/10.1063/1.3551582
Moreover, the geometrical distribution of the particles also influences enormously their heating ability ( http://dx.doi.org/10.1021/jp410717m) but this is something that is difficult to consider a priori.
The biological constraints of the application of magnetic nanoparticles in vivo can be found in several excellent reviews, such as
Reddy et al. 2012 http://pubs.acs.org/doi/abs/10.1021/cr300068p
I hope my answer helps you.
yes non-toxicity is a big deal. I guess that is the correct answer.
Nevertheless, other materials like cobalt ferrite manganese ferrite can also be used but with bio-compatible coating. I am open for other answers.
It has been found that certain metals such as cobalt, nickel, cadmium, zinc, and silver are toxic to biological entities and therefore not suitable for biomedical applications while others such as titanium and iron oxide-based particles are considered significantly less damaging to cells . Also, the Magnetization of Fe3O4 and y-Fe2O3 is high in the range of [ 60-80 emu/g] compared to other magnetic nanoparticles ; due to its superparamagnetic property [ if the particles were < 30 nm ] the temperature of the particles can be quickly increased using an electromagnet by alternating the poles and thus it is used for hyperthermia at required place.
Colloids and Surfaces B, vol. 75, no. 1, pp. 300–309, 2010; Journal of Materials Chemistry, vol. 15, no. 5, pp. 543–547, 2005 ; Swiss Medical Weekly, vol. 140, pp. 7–13, 2010
Is there any method you can suggest that can be used to prepare Fe3O4@Au nanoparticles in a lab which doesnot have any sophisticated facilities?
Thnx
Biocompatibility of the particles is a core issue in the clinical application of magnetic hyperthermia. Most research sticks to iron oxide particles not only because they have proven biocompatibility, but because iron oxide nanoparticles have already been approved for biomedical use both in the US and the EU, setting a precedent for future applications. Nanoparticles made by other materials, even if proven to be biocompatible in in vitro and animal models, would take a long time to transfer into human studies, slowing down the real clinical application of magnetic hyperthermia.
From the purely physical point of view, the heating ability of the particles is a function of the saturation magnetization, anisotropy constant, size of the particle and the temperature, as well as the applied magnetic field. Different materials will have different optimal sizes for maximum heating ability at room temperature, and this is an issue that has to be considered also for in vivo applications: big magnetic particles are usually not colloidal stable and are not able to cross biological barriers. But for a given material, the smaller the particle, the lower the heating ability. All you can aim is to find a compromise between the optimal "physical" and "biological" properties of the particles. You can find an excellent survey on the physics of magnetic hyperthermia in
Carrey et al. 2011
http://scitation.aip.org/content/aip/journal/jap/109/8/10.1063/1.3551582
Moreover, the geometrical distribution of the particles also influences enormously their heating ability ( http://dx.doi.org/10.1021/jp410717m) but this is something that is difficult to consider a priori.
The biological constraints of the application of magnetic nanoparticles in vivo can be found in several excellent reviews, such as
Reddy et al. 2012 http://pubs.acs.org/doi/abs/10.1021/cr300068p
I hope my answer helps you.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles