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Magnetic NPs play a vital role in targeted drug delivery of molecules which improve the drug specificity and reduce the side effect (Enpuku et al. 2001). This approach has also recently been used for magnetic targeting of magnetoliposomes within solid tumors (Fortin‐Ripoche et al. 2006). The liposome filled with magnetic nanoparticles (magnetoliposomes) is highly potential drug carrier and has the advantage to allow at the same time magnetic resonance imaging detection (Martina et al. 2005), making possible noninvasive validation of magnetic targeting (Riviere et al. 2006). In cancer chemotherapeutic treatment, therapeutic compounds with high cytotoxic activities need to be delivered into individual tumor cells to damage or kill them. In the conventional methods, the accumulation of these drugs in the tumor and healthy tissue is equivalent due to the nonspecific nature of drugs injected into the blood systems (Bao et al. 2013). This occurrence gives rise to the side effects such as normal healthy cells are attacked in the procedure of treatment.

Magnetic NPs mediated and targeted drug delivery of molecules can improve the drug specificity and reduce this side effect (Jain 2001). Therapeutic agent attached or encapsulated within magnetic NPs lead to formation of MNPs/therapeutic agent co‐complex. These magnetic carriers are injected into the bloodstream and directed to focus on the tumor location through external applied inhomogeneous magnetic fields (McBain et al. 2008). Magnetic NPs functionalized with the drug in targeted drug delivery can increase the biodistribution and protect the drugs from the microenvironment, exhibiting higher internalization by cancer cells than healthy cells and permitting the usage of the therapeutic agents at low enough doses to decrease the toxicity of chemotherapy (Pankhurst et al. 2003).

A number of studies have confirmed the number of advantages of magnetic NPs for drug delivery. Pankhurst et al. (2003) proved that the targeted delivery technique using magnetic nanoparticles was a major breakthrough to the treatment of many diseases in the clinical practice in current years. Therapeutic compounds are attached to biocompatible magnetic nanoparticles, and the applied magnetic fields are focused on specific targets in vivo. The fields capture the particle complex and result in improved delivery to the target site (Xu and Sun 2012). Magnetic NPs are as carriers for drugs and genes targeted drug delivery and has been one of the most desirable applications of MNPs for chemotherapy (Pankhurst et al. 2003). The application of MNPs for regenerative medicine is based on the noninvasive nature of MRI for transplanted stem cells. MRI provides excellent soft‐tissue contrast with high resolution and can be used for visualization of single cells against a homogeneous background. Usually, iron oxide NPs were loaded into stem cells by passive internalization. The introduction of surface coatings or target ligands may further increase the uptake by cells. There is plenty of research on stem cell tracking by MNP‐aided MRI methodology (Bulte et al. 2002; Bulte and Kraitchman 2004). The use of therapeutic cells, proteins, and nucleic acids in the treatment of various conditions is a highly active area of research (Mok and Zhang 2013); their innate specificity makes such biotherapeutics attractive potential treatments. The ineffective delivery systems frequently hamper the application of biotherapeutics. To overcome this, novel magnetically driven delivery systems have been developed to facilitate the fast, efficient, and site‐specific delivery of biotherapeutic interferences (Chomoucka et al. 2010).