**4.2. Magnetic iron oxide nanoparticles effect on cancer cells**

The concentration of M-IONPs is also important in the assessment of M-IONPs toxicity. In one of our previous studies developed on HaCat cells (human keratinocytes), it was shown that concentrations lower than 25 μg/mL did not induce toxicity in terms of viability and

**Figure 5.** The impact of magnetite and maghemite obtained by combustion method on HaCat cell morphology after 24 h

Shelat and coworkers indicated a dose-dependent cytotoxic effect of M-IONPs on mouse embryonic fibroblast (NIH 3 T3) [101]. It was also assessed the effect of negatively charged superparamagnetic iron oxide nanoparticles on heart cells and no changes in actin cytoskeleton were observed, whereas in the case of brain and kidney cells, a disruption of the actin cytoskeleton was detected, but some increased vascular permeability was seen after exposure [102].

Another sign of toxicity that was described after neural cells exposure to M-IONPs was represented by protein aggregation. In addition, it was shown that M-IONPs induce apoptosis of hepatocytes in a mitochondrial-dependent way consisting of upregulation of pro-apoptotic markers (Bax and Bad) and downregulation of bcl-2 (anti-apoptotic); decrease of mitochondrial membrane potential followed by the release of cytochrome c into the cytosol what leads

Based on the data that were presented in this section, it could be said that the mechanisms involved in M-IONPs toxicity are accumulation of iron ions, oxidative damage by generating

Mutagenic effects of M-IONPs on different murine and mammalian normal cell lines were

to activation of caspases cascade and apoptosis induction (**Figure 6**) [91].

reactive oxygen species, protein aggregation and apoptosis.

clearly synthesized in an extensive review [103].

cytoskeleton changes (**Figure 5**) [100].

stimulation.

244 Iron Ores and Iron Oxide Materials

SPIONs (superparamagnetic iron oxide nanoparticles) are the most frequently used iron oxide nanoparticles in the biomedical applications due to their proper size (range between 50 and 200 nm) and the magnetic properties responsible for the lack of particle aggregates *in vivo.* Another type of iron oxide nanoparticles is represented by USPIONs (ultra-small superparamagnetic iron oxide nanoparticles), which have a diameter lower than 50 nm. The mandatory features of M-IONPs that must be analyzed in order to establish the bioavailability and the possible interactions with endogenous compounds (proteins, immune system cells, etc.) are: (i) size (the recommendable size for biomedical applications is between 10 and 200 nm; the ones that are too big will be assimilated by liver and spleen cells, the ones that are too small will be filtrated by the kidneys and their life in the bloodstream is reduced); (ii) superparamagnetism and (iii) presence of a coating agent [104].

The affinity of liver, spleen, bone marrow and lymph nodes for SPIONs after their removal from the blood by the mononuclear phagocytic system (MPS) after intravenous administration represents the reason for the study of this type of nanoparticles as contrast agents but also for their use as delivery tools for chemotherapeutic agents. USPIONs due to their small size possess the capacity to escape macrophages of MPS surveillance and their circulation time is higher, but they also encounter macrophages in deeper compartments.

The changes concerning the surface of the nanoparticles by using a coating agent proved to exert multiple roles: to improve colloids stability, to enhance the bioavailability and the bloodstream half-life and to reduce precipitation and formation of conglomerates [104, 105]. M-IONPs were used as drug delivery agents and as contrast agents based on their potential to activate at cellular and molecular levels [105].

Due to the multiple applications of M-IONPs in biomedical fields (drug delivery, as contrast agents, hyperthermia treatment), it was also verified the effects of the hollow nanoparticles (without payload) on different tumor cell lines.

marrow-derived stromal cells for severe cases of Multiple Sclerosis therapy and Supravist

Preclinical Aspects on Magnetic Iron Oxide Nanoparticles and Their Interventions as Anticancer…

http://dx.doi.org/10.5772/intechopen.74176

247

The intrinsic magnetic properties, the biocompatibility and biodegradability and the capacity to respond to an external magnetic field are unique features that recommend magnetic iron oxide nanoparticles as promising nanomaterials in biomedical applications. The recent advances in this field led to the synthesis of engineered and targeted M-IONPs that might be successfully applied for smart therapies, including controlled drug release, hyperthermia treatment, magnetofection and gene delivery, mapping of lymph nodes and tissue engineering. M-IONPs could be considered theranostics tools based on their capacity to combine their use in diagnostic, treatment and follow-up of a pathology. Despite all these beneficial effects, an important matter should be taken into consideration when M-IONPs are administered *in vivo*, this matter consisting in the thorough analysis of the factors that might induce toxic reactions like size, charge, coating agent, functional groups and shape. There are still some challenges to achieve M-IONPs optimum efficacy and safety, but the existent drawbacks can be corrected by the improvement of their proper-

(ferucarbotran—small size nanoparticles)—as enhancing blood pool agent [104, 109].

ties by the means of appropriate methods, further studies and inclusion in clinical trials.

project number PN-III-P4-ID-PCE-2016-0765, within PNCDI III.

, Elena Dorina Coricovac<sup>1</sup>

\*Address all correspondence to: dorinacoricovac@umft.ro

, Cornelia Silvia Păcurariu<sup>2</sup>

This work was supported by a grant of Minister of Research and Innovation, CNCS-UEFISCDI,

1 Faculty of Pharmacy, "Victor Babes" University of Medicine and Pharmacy, Timisoara,

2 Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of

[1] Reddy LH et al. Magnetic nanoparticles: Design and characterization, toxicity and biocompatibility, pharmaceutical and biomedical applications. Chemical Reviews.

\*, Codruta Marinela Soica<sup>1</sup>

,

and Cristina Adriana Dehelean<sup>1</sup>

**5. Concluding remarks**

**Acknowledgements**

**Author details**

Elena-Alina Moacă<sup>1</sup>

Timisoara, Romania

2012;**112**:5818-5878

**References**

Romania

Iulia Andreea Pinzaru<sup>1</sup>

As mentioned in the previous section, M-IONPs mediate DNA lesions in normal cells, and this property is also exerted in the case of tumor cells. The effect observed was dose-dependent and time-dependent and consisted of damage of tail length and DNA strand breaks. The results were similar in all the tumor cell lines tested: human breast cancer cell line (MCF-7), human fibrosarcoma cells, lung cancer and cervix carcinoma cells [103].

Another mechanism of M-IONPs by which are able to harm cancer cells is represented by the ability to induce magnetic hyperthermia in the form of heat generated by the release of energy after applying a high-frequency alternating magnetic field. The principle of action of this technique consists in raising the cell temperature abnormally to 41–45°C, which leads to significant detrimental effects that can be reversible in the case of normal cells whereas irreversible for cancer cells [105].

A novel proposed mechanism for M-IONPs-induced cell death is enucleation described by Paunescu and coworkers, process observed after exposure of breast cancer cells (MCF-7) and human melanoma (SK-BR-3) to magnetic iron oxide nanoparticles obtained by combustion synthesis [106]. The enucleation phenomena is well described for erythroid terminal differentiation process and there is also used a term in the literature "enucleation sign" that is specific for enhanced computed tomographic images of the ruptured hepatocellular carcinoma. The definition for this term is "the separation of tumor content with intraperitoneal rupture into the perihepatic space, which is seen as low attenuating lesion from peripheral enhancing rim on arterial phase imaging" [107]. The process observed by Paunescu et al. was described as a non-physiological process and it was unrelated with the process described for erythroblast enucleation [106].

The M-IONPs proved a cytotoxic effect against murine melanoma cells B16, cytotoxicity evaluated by the means of MTT viability assay [108].

Other mechanisms of action as anticancer agents may be attributed to M-IONPs, mechanisms that are related with the effects induced by the chemotherapeutical agents loaded in the engineered nanoparticles. The large surface-to-volume ratio characteristic for M-IONPs make them suitable to adsorb proteins or load drugs and attractive for *in vivo* applications, such as MRI, drug and gene delivery, cancer treatment, hard tissue repair and tissue engineering and biosensors [105].

Recent studies mention the use of M-IONPs as improved contrast agents in the diagnosis of cardiovascular pathologies, mainly in atherosclerosis for detection of unstable plaques by the means of MRI (magnetic resonance imaging) [104]. The commercial products based on M-IONPs applied as contrast agents in MRI are: Ferumoxytol (Feraheme—detection of primary tumors and cancer lymph node metastasis), Ferumoxides (Feridex—detection of liver lesions), Ferucarbotran (Resovist—detection of small focal liver lesions), Ferumoxtran—10 (Combidex or Sinerem—detection of metastatic disease in lymph nodes), etc. [104]. Some of these products are included in clinical trials for additional effects, such as Endorem for tracking monocytes and inflammation cells, Feridex—to keep track of adult bone marrow-derived stromal cells for severe cases of Multiple Sclerosis therapy and Supravist (ferucarbotran—small size nanoparticles)—as enhancing blood pool agent [104, 109].
