Cancer is one of the biggest challenges facing the medical research in our time. The goals are to improve not only the therapeutic outcome, even in the cases of advanced and metastatic cancer, but also the methods of treatment, which often have considerable adverse effects. In addition, the current developments, such as demographic change, population growth, and increasing healthcare costs, have to be taken into consideration. In all likelihood, nanotechnology and, in particular, the use of magnetic nanoparticles consisting of the elements nickel, cobalt, and iron can make a significant contribution. The greatest potential can be ascribed to the drug delivery systems: magnetic nanoparticles are functionalized by binding them to various substances, including chemotherapeutic agents, radionuclides, nucleic acids, and antibodies. They can then be guided and accumulated using a magnetic field. Magnetic nanoparticles may be useful in overcoming cancer drug resistance. They also contribute to realizing a combination of diagnostic investigation and therapy in the field of “theranostics”. 

Magnetic nanoparticle drug delivery opens the possibility of using local enhancement methods, so that the drug can accumulate and act in a previously determined area. This method was first described in 1978. It is based on the usage of three elements: iron (Fe), cobalt (Co), and nickel (Ni). All are ferromagnetic under physiological conditions, although they do not exhibit the same magnetization. The nanoparticles are coated in order to prevent agglomeration, ensure stability, and provide a positive effect on bio-distribution. A wide variety of materials, including fatty acids, polyethylene glycol (PEG), dextran, and chitosan may be used. Magnetic nanoparticles can transport various different substances and molecules, such as chemotherapeutic agents, antibodies, nuclear acids, radionuclides, etc. In principle, this approach can be used for any tumour, irrespective of its size, differentiation, or site.

The mode of administration is essential when using magnetic nanoparticles in cancer therapy. Depending on the purpose and target structure, the nanoparticles can be applied parenterally (intravenously or intra-arterially), by mouth, as an aerosol, or interstitially, i.e., directly into the tissue. Intravenous injection is usually preferred though. Many of these particles, however, are being trapped in the liver and spleen and get excreted via the kidneys. The distribution of magnetic nanoparticles can be an active or passive process. Passive distribution occurs mainly by diffusion, after parenteral injection. The greater permeability of the tumor blood vessels is, thereby, useful, although it is often counteracted by the high pressure in the interstitial tissue of cancer. The nanoparticles can also be transported actively to the tumor by coupling them with appropriate tumor-specific ligands. Magnetic drug targeting (MDT) to treat cancer is a specific form of drug delivery, being developed at our centre that uses chemotherapeutic agents directly associated with superparamagnetic iron oxide nanoparticles. The resulting suspension (Ferro fluid) is injected into an artery, directly supplying the tumor.

CONCLUSION

The treatment of cancer has already made considerable advances with the use of magnetic nanoparticles. There are numerous possibilities for their use. Drug delivery allows a wide variety of substances to be transported in a targeted manner to the site where they are needed and intended to act.