Magnetic nanoparticles – an effective medium for biomedical applications

Written by Rabia Iqbal

MNPs are the group of engineered and specific materials of sizes less than 100nm, that can be controlled under the effect of an external magnetic field. Due to their versatile features i.e. small size, super-paramagnetism and low toxicity, they can be used for waste water treatment, biomedical applications.

For biomedical applications ,magnetic Magnetite (Fe 3 O 4 ) NPs are considered best for biomedical applications like in magnetic resonance imaging (MRI), drug delivery systems, medical diagnostics, cancer therapy, microwave devices, magneto-optic devices etc.


Synthesis of MNPs by Co-precipitation:



For production of MNPs of composed sizes and magnetic features, co precipitation is convenient and commonly used method. In this method, under inert atmosphere, at room or elevated temperature, MNPs are manufactured when base is added into aqueous salt solution. Then it is allowed it to precipitate MNPs. Due to simple procedure and material required in this method, it is widely used for biomedical applications.

Similarly new methods like green technology, microemulsion, sol gel process, thermal decomposition can be used for preparation of MNPs by overcoming their drawbacks with great efficiency.

Some types of nanoparticles

MNPs in biomedical application:


  • In the delivery of drugs:

MNPs act as vehicle in the delivery of drug by injecting into blood stream .Under the influence of magnetic field; they reach the target site of disease. The efficiency of MNPs can be enhanced by proper blood transmission, circulation and external magnetic fields. Super magnetic iron oxide nanoparticles (SPIONs) along with ligands or proteins, because of its enhanced biocompatibility, are of great importance in drug delivery application.


  • In cancer therapy:

MNPs of different sizes can be used for examination and therapy of malignant tumors. Magnetic hysteria causes heating of tumor site through injection, which results in the cell death of cancer cells. Hence using the mechanism of magnetic energy conversion into heat, MNPs can be used in treatment of cancer.

  • In magnetic resonance imaging (MRI):

MNPs have been generally utilized as a part of MRI applications. For example, iron oxide nanoparticles can be used for cancer imaging, in vivo tracking of iron oxide doped undifferentiated cells and in vivo checking of transplanted tissues .Moreover, MNPs can filled in as instrument for cell imaging.

  • In tissue engineering:

Tissue engineering is a technology used for regeneration of tissue without damage. Magnetically responsive composite scaffolds are very useful materials for control mechanical modulation and release of growth factor. Utilizing magnetic nanoparticles, tissue engineering process can be made more successful.

Mechanism of magnetic nanoparticles

  • In biosensors:

Biosensor is diagnostic device for detection of analytes using biological material.

It converts biological event into easily measured signals. Due to ferromagnetic characteristics of MNPs, these can be used with biosensors .By diffusion into sample, or onto surface of biosensor, MNPs plays significant role in sensing application.


  • Invention by researchers:

A method has been introduced by researchers in Switzerland that repairs stress-induced cracks in asphalt by mixing iron oxide nanoparticles with bitumen(thick black binder obtained from crude oil).There is proper attention required to implement this method on roads..

  • Conclusion:

Scientists are trying to use MNPs for effective purposes. New methods are implemented for narrow sized nanoparticles by overcoming their drawbacks .But still there are some challenges to be checked for better applications i.e. there is a need to improve biocompatibility and reduce toxicity of MNPs. So by deeper understanding of MNPs and controlling factors like shape, size distribution, particle size, and magnetic properties of MNPs, these can be of more importance in biomedical applications.





  • Majidi, S., Zeinali Sehrig, F., Farkhani, S. M., Soleymani Goloujeh, M., & Akbarzadeh, A. (2016). Current methods for synthesis of magnetic nanoparticles. Artificial cells, nanomedicine, and biotechnology44(2), 722-734.


  • Li, X., Wei, J., Aifantis, K. E., Fan, Y., Feng, Q., Cui, F. Z., & Watari, F. (2016). Current investigations into magnetic nanoparticles for biomedical applications. Journal of Biomedical Materials Research Part A104(5), 1285-1296.




About the author

Rabia Iqbal