**4.1 Applications of IONPs**

IONPs possess unique physicochemical characteristics, as well as superparamagnetic with high surface area, non-toxicity, and biocompatibility [15]. IONPs have effectively been applied in various in biomedical applications [34, 58–68], since they can selectively target a specific biological unit by applying an external magnetic field. Iron oxide nanoparticles of the type, Fe3O4, have shown to be promising candidate as a contrast agent for magnetic resonance imaging. This is due to superparamagnetic or paramagnetism which creates an outer magnetic field around itself when exposed to an external magnetic field; this permits the increase of image resolution and decreases aggregation of particles due to fast dephasing of the spins through a so-called magnetic susceptibility effect. This enhances the signal intensity to help distinguish between healthy and unhealthy cells [79–81]. Studies have reported IONPs as promising MRI contrast agents for in vivo rat studies.

*Mineralogy - Significance and Applications*

*PL spectra of InP/ZnSe nanocrystals dispersed in hexane (A) PL spectra of α-Fe2O3-InP/ZnSe nanocomposite* 

**146**

**Figure 7.**

**Figure 5.**

**Figure 6.**

*dispersed in PBS (B) [58].*

*Cytotoxicity of the iron oxide-InP/ZnSe nanocomposite [58].*

*Magnetization curves of the MNPs and the nanocomposite material.*

In of the studies, rats were anesthetized and subcutaneous injection containing 2.5 mg (Fe3O4)/kg body weight of Fe3O4 samples was given every 6 hours into the right hand of the animal. MRI scans taken after every 6 hours showed accumulation occurred on the lymph nodes, however none was noticed on the left-hand side. The study proved successful imaging of lymphatic system using iron oxide as a contrast agent [82]. At present, numerous studies are still undergoing clinical trials and only two types of dextran-capped IONPs have been clinically approved as MRI contrast agents, highlighted in **Table 3** [83]. These two are commonly known as, Ferucarbotran (Resovist) with particle size of about 60 nm, and Ferumoxides (Feridex in America and Endorem in Europe) have a broader particle size distribution between 120 and 180 nm (**Table 3**) [82, 83].

#### **4.2 Application of fluorescent magnetic NPs**

Over the years, scientists have shown that one way to improve on current nanomaterials was to combine two or more desired physical properties into one structure. The wish sparked many research ventures into the synthesis or assembly of these type multifunctional materials, also how many entities is effective and which areas could benefit most from these nanocomposites. Incorporation of a fluorescent material within a magnetic NP might modify its band gap energy as well as the luminescence properties [84]. Such multimodal properties are highly desirable specifically in the biomedical diagnosis and therapy [85, 86]. This nanocomposite would not only be improving current applications, but find better ways to achieve a desired outcome. These magnetic-fluorescent nanocomposites could be multimodal assays for in vitro- and in vivo-bioimaging applications such as MRI and fluorescence microscopy [27]. Other exciting applications of these nanocomposites include cell tracking, cytometry and magnetic separation, which could be easily controlled and monitored using fluorescent or confocal microscopy and molecular resonance imaging (MRI) [24, 87, 88]. They could also be used as bimodal agents for cancer therapy, additionally encompassing hyperthermic and photodynamic properties [89]. These fluorescent-magnetic nanocomposites can also be utilized as a multimodal therapeutic and diagnostic tool that can simultaneously locate, diagnose and treat various diseases [90–92]. In another study, Mandal et al. prepared multifunctional nanobiocomposite for targeted drug delivery in cancer therapy. Iron oxide nanoparticle of 15 nm in diameter was used as a contrast agent to enhance MRI and the anticancer drug gemcitabine. In vitro studies between treated and untreated cancer cell lines showed black spots on the gastric cancer cell lines that were treated with the nanobiocomposites whereas no reduction in the signal of the untreated cells. The study concluded that the iron oxide nanobiocomposite can act as contrast agent in MRI and also as a targeted drug delivery system in vivo using rats as an animal model [89]. In similar study, Ahmed et al. prepared the thiol capped-CdTe QDs coated with CTAB. The nanocomposites showed distinct magnetic and fluorescent properties even after isolation with a magnet it still maintained good PL intensity. The nanocomposite was conjugated to antibodies for the imaging of the colon carcinoma cells. No green fluorescence was observed on the surface of the cells. In vitro studies showed low toxicity at 64 fold dilutions. This demonstrated their potential as probes for imaging and ultimately provides a new class of multimodal diagnostics NPs for the complex biological systems [93, 94]. Hence, we focus on the developments of magnetic-fluorescent nanocomposites and their biological applications specifically, multimodal imaging for breast cancer diagnostics.

#### *4.2.1 Multimodal bioimaging*

Biological imaging or bioimaging is defined as the study of biological processes at the cellular and/or and subcellular level. Several biological imaging techniques

**149**

**Names** Clariscan ferristene

Ferumoxsil AMI-121

Ferumoxides AMI-25

Lumirem/Gastromark

Ferucarbotran SHU-555A

Ferumoxytol code 7228

Endorem/feridex

ferumoxtran-10 AMI-227

Resovist SHU-555C Supravist

Feruglose NC100150

VSOP-C184 *Data edited from [82].*

**Table 3.**

*Characteristics of SIONPs agents undergoing clinical investigation clinical or commercial investigation.*

GE Healthcare

Blood pool agent

(discontinue)

Ferropharm

Blood agent, cellular labeling

r1 = 14

Citrate

7

r2 = 33.4

Advanced magnetics

Guerbet, advanced

magnetics

Schering

Blood pool agent, cellular labeling

r1 = 10.7

Carboxydextran

21

r2 = 38

N/A

PEGylated starch

20

Macrophage imaging blood pool agent, cellular labeling

Metastatic lymph node imaging

r1 = 9.9

Dextran T10, T1

15–30

r2 = 65

Schering

Liver imaging, cellular labeling

r1 = 9.7 r2 = 189

r1 = 15 r2 = 89

Carboxylmethyldextran

30

Carboxydextran

60

Guerbet, advanced magnetics

Guerbet, advanced magnetics

GE Healthcare

Oral GI imaging

Oral GI imaging

Liver imaging, cellular labeling

r1 = 10.1 r2 = 120

Dextran T10

120–180

N/A

**Company**

**Applications**

**Relaxometric properties**

N/A

Sulfonated styrenedivinylbenzene copolymer

Silicon

**Coating agent**

**Hydrodynamic size (nm)**

3500

*Chemical Synthesis and Characterization of Luminescent Iron Oxide Nanoparticles…*

*DOI: http://dx.doi.org/10.5772/intechopen.88165*

300


*Chemical Synthesis and Characterization of Luminescent Iron Oxide Nanoparticles… DOI: http://dx.doi.org/10.5772/intechopen.88165*

**Table 3.**

 *Characteristics of SIONPs agents undergoing clinical investigation clinical or commercial investigation.*

*Mineralogy - Significance and Applications*

tion between 120 and 180 nm (**Table 3**) [82, 83].

**4.2 Application of fluorescent magnetic NPs**

specifically, multimodal imaging for breast cancer diagnostics.

Biological imaging or bioimaging is defined as the study of biological processes at the cellular and/or and subcellular level. Several biological imaging techniques

In of the studies, rats were anesthetized and subcutaneous injection containing 2.5 mg (Fe3O4)/kg body weight of Fe3O4 samples was given every 6 hours into the right hand of the animal. MRI scans taken after every 6 hours showed accumulation occurred on the lymph nodes, however none was noticed on the left-hand side. The study proved successful imaging of lymphatic system using iron oxide as a contrast agent [82]. At present, numerous studies are still undergoing clinical trials and only two types of dextran-capped IONPs have been clinically approved as MRI contrast agents, highlighted in **Table 3** [83]. These two are commonly known as, Ferucarbotran (Resovist) with particle size of about 60 nm, and Ferumoxides (Feridex in America and Endorem in Europe) have a broader particle size distribu-

Over the years, scientists have shown that one way to improve on current nanomaterials was to combine two or more desired physical properties into one structure. The wish sparked many research ventures into the synthesis or assembly of these type multifunctional materials, also how many entities is effective and which areas could benefit most from these nanocomposites. Incorporation of a fluorescent material within a magnetic NP might modify its band gap energy as well as the luminescence properties [84]. Such multimodal properties are highly desirable specifically in the biomedical diagnosis and therapy [85, 86]. This nanocomposite would not only be improving current applications, but find better ways to achieve a desired outcome. These magnetic-fluorescent nanocomposites could be multimodal assays for in vitro- and in vivo-bioimaging applications such as MRI and fluorescence microscopy [27]. Other exciting applications of these nanocomposites include cell tracking, cytometry and magnetic separation, which could be easily controlled and monitored using fluorescent or confocal microscopy and molecular resonance imaging (MRI) [24, 87, 88]. They could also be used as bimodal agents for cancer therapy, additionally encompassing hyperthermic and photodynamic properties [89]. These fluorescent-magnetic nanocomposites can also be utilized as a multimodal therapeutic and diagnostic tool that can simultaneously locate, diagnose and treat various diseases [90–92]. In another study, Mandal et al. prepared multifunctional nanobiocomposite for targeted drug delivery in cancer therapy. Iron oxide nanoparticle of 15 nm in diameter was used as a contrast agent to enhance MRI and the anticancer drug gemcitabine. In vitro studies between treated and untreated cancer cell lines showed black spots on the gastric cancer cell lines that were treated with the nanobiocomposites whereas no reduction in the signal of the untreated cells. The study concluded that the iron oxide nanobiocomposite can act as contrast agent in MRI and also as a targeted drug delivery system in vivo using rats as an animal model [89]. In similar study, Ahmed et al. prepared the thiol capped-CdTe QDs coated with CTAB. The nanocomposites showed distinct magnetic and fluorescent properties even after isolation with a magnet it still maintained good PL intensity. The nanocomposite was conjugated to antibodies for the imaging of the colon carcinoma cells. No green fluorescence was observed on the surface of the cells. In vitro studies showed low toxicity at 64 fold dilutions. This demonstrated their potential as probes for imaging and ultimately provides a new class of multimodal diagnostics NPs for the complex biological systems [93, 94]. Hence, we focus on the developments of magnetic-fluorescent nanocomposites and their biological applications

**148**

*4.2.1 Multimodal bioimaging*

have been developed with different in principles and equipment such as optical bioluminescence, optical fluorescence, ultrasound imaging, MRI, single-photonemission computed tomography (SPECT), and positron emission tomography (PET), X-ray, thermal imaging, X-ray computed tomography (CT), hyperspectral imaging, and magnetic resonance imaging (MRI) [82]. Over three decades, these techniques have continuously had rapid developments and incremental improvements due to their wide application various biological fields. Multimodal magnetic nanoparticles have significant features as they could act as imaging probes and drug delivery systems. These NPs offer unique characteristic as a dual contrast agent that can combine fluorescent microscopy and MRI. Both techniques are well studied, MRI have been widely applied for in vivo imaging diagnosis, meanwhile fluorescence microscopy are mostly applied for in vitro imaging. Optical imaging is a promising tool as it provides better spatial resolution and performance in sensibility for in vitro imaging, however tissue penetration is limited to few millimeters. Moreover, MRI provides excellent spatial resolution and deep tissue contrast for better in vivo imaging. The amalgamation fluorescent microscopy and MRI opens new possibilities of rapid analysis for diagnosis of diseases and pathogens. In recent years, significant advances have been made in development of fluorescent magnetic nanoparticles as multimodal agents by using magnetic contrast agents. Zhang et al. prepared fluorescent mesoporous silica coated-iron oxide nanoparticles of ~10 nm with high magnetic resonance sensitivity and excellent cell labeling efficiency for detection of neural progenitor cells using MRI [95, 96]. In another study, monodispersed magnetic nanoparticles functionalized with an organic dye showed optical activity and good biocompatibility [93, 94]. In recent study, Guo et al. synthesized superparamagnetic monodispersed core@ shell CoFe2O4@MnFe2O4 NPs coated with poly(isobutylene-alt-maleic anhydride) PEG and then functionalized with folic acid. The resulting multifunctional

**Figure 8.** *Cytotoxicity studies of bare and functionalized iron oxide nanoparticles using MCF-12A and KMST 6 cell lines.*

**151**

*Chemical Synthesis and Characterization of Luminescent Iron Oxide Nanoparticles…*

nanocomposite exhibit good biocompatibility, high T2 relaxation, and long-term fluorescence stability to enhance the targeted MRI and fluorescent tracking for in vivo and in vitro studies [97, 98]. Recent research advancements have produced several excellent magnetic fluorescent nanocomposites. In our study, we prove genes are capable of being used for potential development of serum markers in the diagnosis, of breast cancer or early detection of poor-outcome breast cancer. However, we found that these proteins are present in a very low concentration, which makes the diagnosis a challenging process, however not impossible. The synthesized method used for the preparation of bare and capped iron oxide nanoparticles show low cytotoxicity, which is a strong foundation for future contrast agent for in vivo studies of certain cancer therapies. In addition, it has been proved that different ligand molecules have different effects on the toxicity of the nanoparticles, for example, Liu et al. [93, 94] carried out cytotoxicity study of iron oxide coated with acridine orange using 293 T cells. They varied the concentration of the iron oxide from 0 to 80 mg/mL and observed cell viability greater than 78%. In similar example, In comparison. The lower cell viability observed here could be attributed to acridine orange used and not the iron oxide. In a very recent study, Zhang et al. synthesized superparamagnetic Fe2O3 NPs with a diameter of 51.88 nm showed neurotoxic effects in PC12 cell line, in a dose-dependent manner at 60–200 mg/mL, but not at 10–50 mg/mL [99]. The ligands chosen in our study appeared not to affect the toxicity of the iron oxide nanoparticles despite using higher concentration compared to the concentration reported by Liu et al. and

We were able to successfully synthesize iron oxide magnetic nanoparticles using the co-precipitation method. The synthesized nanoparticles were then functional-

We were also able to successfully synthesize InP/ZnSe nanocrystals using the hot injection method. The synthesized nanocrystals were capped with oleic acid, which was the stabilizing agent in the nanocrystals' synthesis. The InP/ZnSe then underwent a ligand exchange and thus the oleic acid capped QDs were replaced with MPA

The ultimate objective of the study was realized when we successfully fabricated a magnetic-luminescent bifunctional nanocomposite material was prepared using thiol-chemistry, this allowed the direct combination of the QDs and MNPs. The nanocomposite material was characterized and observed to exhibit both magnetic and luminescent properties. The SQUID analysis showed that the Fe3O4-InP/ZnSe nanocomposite material has a magnetic saturation of 6.03 emu/g. The PL studies demonstrated that the nanocomposite material had a fluorescence of approximately 40,000 arbitrary units. The nanocomposite material had significantly lower mag-

To conclude the study we carried out extensive in vitro cytotoxicity study to evaluate the toxicity of the iron oxide nanoparticles, functionalized iron oxide nanoparticles, InP/ZnSe nanocrystals, and Fe2O3-InP/ZnSe nanocomposite. The KMST 6 and MCF-12A cell lines were exposed to increasing concentration of the nanoparticles. The cells were incubated with the nanoparticles for 24 hours and the cell viability was determined using MTT assay. The cell viability for all types of the nanomaterials was greater than 90% using both MCF-12A and KMST6 cell lines. This suggested that the particles are safe hence not limiting their biological

netic and fluorescence properties in comparison to their pure forms.

applications and also safe in regard to handling.

*DOI: http://dx.doi.org/10.5772/intechopen.88165*

Zhang et al. (**Figure 8**) [93, 94, 99].

**5. Conclusion**

ized with DMSA.

capped QDs.

*Chemical Synthesis and Characterization of Luminescent Iron Oxide Nanoparticles… DOI: http://dx.doi.org/10.5772/intechopen.88165*

nanocomposite exhibit good biocompatibility, high T2 relaxation, and long-term fluorescence stability to enhance the targeted MRI and fluorescent tracking for in vivo and in vitro studies [97, 98]. Recent research advancements have produced several excellent magnetic fluorescent nanocomposites. In our study, we prove genes are capable of being used for potential development of serum markers in the diagnosis, of breast cancer or early detection of poor-outcome breast cancer. However, we found that these proteins are present in a very low concentration, which makes the diagnosis a challenging process, however not impossible. The synthesized method used for the preparation of bare and capped iron oxide nanoparticles show low cytotoxicity, which is a strong foundation for future contrast agent for in vivo studies of certain cancer therapies. In addition, it has been proved that different ligand molecules have different effects on the toxicity of the nanoparticles, for example, Liu et al. [93, 94] carried out cytotoxicity study of iron oxide coated with acridine orange using 293 T cells. They varied the concentration of the iron oxide from 0 to 80 mg/mL and observed cell viability greater than 78%. In similar example, In comparison. The lower cell viability observed here could be attributed to acridine orange used and not the iron oxide. In a very recent study, Zhang et al. synthesized superparamagnetic Fe2O3 NPs with a diameter of 51.88 nm showed neurotoxic effects in PC12 cell line, in a dose-dependent manner at 60–200 mg/mL, but not at 10–50 mg/mL [99]. The ligands chosen in our study appeared not to affect the toxicity of the iron oxide nanoparticles despite using higher concentration compared to the concentration reported by Liu et al. and Zhang et al. (**Figure 8**) [93, 94, 99].
