In the recent years, nanotechnology has witnessed a rapid development for biomedical applications. The newly developed nanoparticle systems is expected to have a revolutionary impact on brain cancer diagnosis and therapy .
Nanotechnology involves the design, synthesis, and application of particles with at least one dimension in the size range of 1–100 nm with optical, thermal, and magnetic properties.
They are expected to be promising systems that offer new opportunities to overcome the limitations of current brain tumor management options. .
Major obstacles facing brain tumor treatment:
1- The structural complexity of the brain
2- the heterogeneous and invasive nature of many brain tumors
3- Difficulty in identifying tumor margins.
4- Insufficient accumulation of therapeutic agents at the site of a tumor.
5- Acquired drug resistance to chemotherapy.
The Brain barriers:
Unlike the other body organs, the brain is protected by the blood-brain barrier (BBB) which prevents the passage of harmful endogenous and exogenous molecules but inspit of this advantage it also becomes a disadvantage as it is a major limiting factor for anti-brain tumor therapy.
The second barrier that prevents the passage of systemically administrated drugs to the brain is the blood-cerebrospinal fluid barrier (CSF) which is tightly bound choroid epithelial cells that regulates molecule penetration within the interstitial fluid of the brain parenchyma. This barrier prevents most macromolecules from passing into the CSF from the bloodstream.
The third barrier is the blood-tumor barrier. The tight junctions of endothelial cells in the tumor are significantly compromised which also limits drug penetration from the bloodstream into the tumor .
Magnetic Nanoparticles' Structure:
MNPs are composed of comprised core-shell morphology with an iron oxide core that usually is magnetite [Fe3O4] or maghemite [Fe2O3], coated with a biocompatible material such as polysaccharide, synthetic polymer, lipid or protein .
Advantages of using MNPs for screening and treating brain tumors:
1- Nanoparticles have also proved to have a large surface that contributes to their high loading capacity. As drug delivery systems, they have been shown to improve drug solubility, prolong blood circulation half-life, and control drug-release, hydrophilic or hydrophobic.
2- Many nanoparticle delivery systems are designed to respond to various environmental conditions such as pH and temperature .
3- Using MNPs for imaging and therapy require a special surface coating that is nontoxic and biocompatible. The size of MNPs plays a vital role in the delivery of MNPs as larger NPs may be difficult to target malignant brain tumors .
Mechanism of action:
MNPs properties can be used for improving their delivery to tumors and the core of MNPs allows them to be guided by an external magnetic field. This interaction between the locally administered MNPs and the external magnetic field increases their retention at the tumor site.
- In a recently published study, IONPs coated with a polycationic polyethyleneimine have been used for brain tumor magnetic targeting and intra-arterial drug delivery .
1- Wankhede, M., Bouras, A., Kaluzova, M., & Hadjipanayis, C. G. (2012). Magnetic nanoparticles: an emerging technology for malignant brain tumor imaging and therapy. Expert review of clinical pharmacology, 5(2), 173-186.
2- Cheng, Y., Morshed, R. A., Auffinger, B., Tobias, A. L., & Lesniak, M. S. (2014). Multifunctional nanoparticles for brain tumor imaging and therapy. Advanced drug delivery reviews, 66, 42-57.