Introduction
Nanotechnology is a science with great potential that has played a vital role in the development of useful materials in many fields, including medicine in recent years. According to the recommendation of the European :union: Commission, particles with sizes ranging from 1 to 100 nm (including nanoparticle coating) are considered nanoparticles [1]. The shape and size of nanoparticles are crucial parameters in their synthesis and applications because nanoparticles increase the reactivity and ion transport in the environment due to their high surface-to-volume ratio, which is the result of their very small size. Also, physical properties, such as shape, composition, charge, and solubility can especially change their behavior [2].
Recent nanotechnology studies in biomedical and pharmaceutical sciences have led to significant improvements in common drug delivery systems. Nanoparticles can be classified into four basic material categories: Carbon-based materials (containing carbon), inorganic materials (metallic and oxide nanoparticles), organic-based materials (made of organic materials excluding carbon), and composite materials (combination with larger materials or bulky materials) [3]. Mineral nanoparticles include transition metals and metal oxides (silver, iron, titanium), alkaline earth metals (calcium, magnesium), and non-metals (selenium, silicates), which have been used in various fields. Iron oxide nanoparticles (IONPs) are inorganic nanoparticles composed of ferromagnetic materials. The magnetization of IONPs has shown significant advantages, such as low production cost, environmental safety, stability, and high compatibility [4]. On the other hand, the most common biomedical applications include magnetic separation, targeted drug delivery, magnetic resonance imaging (MRI), hyperthermia by fluid containing magnetic nanoparticles, etc. Another use of IONPs, which has received a lot of attention in therapeutic and diagnostic nanomedicine, is the use of hyperthermia and also the ability to improve the effect of chemotherapy drugs in the conditions of combined treatment [5].
Due to the increasing growth of studies on the application of IONPS in the field of treatment and diagnosis and the need to integrate the findings and applications of these nanoparticles, this review article examines the characteristics and recent biomedical applications of IONPs in cancer diagnosis and treatment.
Stabilization and functionalization of iron oxide nanoparticles (IONPS)
The application of IONPs in biomedical sciences depends on three factors, morphology, size, and surface characteristics. During the synthesis, the morphology of IONPs can be affected by several factors, such as the presence of surfactants, concentration of reactants, reaction temperature, or time [6]. Morphology can also affect circulation time, cellular uptake, and biodistribution. Some studies have focused on the shape of nanoparticles for anticancer drug delivery. However, the effect of morphology on the biodistribution of IONPs has not been extensively studied. The size of nanoparticles determines their average circulation time in the bloodstream, for example, particles with a diameter of less than 10 nm are removed from the circulation through clearance by the kidneys, while particles with a diameter of larger than 200 nm are concentrated in the spleen or absorbed by the body’s phagocytic cells. Nanoparticles with sizes between 10 and 200 nm are ideal for biomedical applications because they have a longer circulation time, which increases the effect of permeability and persistence in tumor tissues. In this way, IONPs with a diameter of less than 2 nm are not suitable for medical use because they may cause toxic effects that can damage intracellular organelles [