Design of Magnetic Nanoplatforms for Cancer Theranostics

Cancer is the top cause of death globally. Developing smart nanomedicines that are capable of diagnosis and therapy (theranostics) in one–nanoparticle systems are highly desirable for improving cancer treatment outcomes. The magnetic nanoplatforms are the ideal system for cancer theranostics, because of their diverse physiochemical properties and biological effects. In particular, a biocompatible iron oxide nanoparticle based magnetic nanoplatform can exhibit multiple magnetic–responsive behaviors under an external magnetic field and realize the integration of diagnosis (magnetic resonance imaging, ultrasonic imaging, photoacoustic imaging, etc.) and therapy (magnetic hyperthermia, photothermal therapy, controlled drug delivery and release, etc.) in vivo. Furthermore, due to considerable variation among tumors and individual patients, it is a requirement to design iron oxide nanoplatforms by the coordination of diverse functionalities for efficient and individualized theranostics. In this article, we will present an up–to–date overview on iron oxide nanoplatforms, including both iron oxide nanomaterials and those that can respond to an externally applied magnetic field, with an emphasis on their applications in cancer theranostics.

The effects of superparamagnetic iron oxide nanoparticle exposure on gene expression patterns in the neural stem cells under magnetic field

Background: Due to the excellent reliable traceability and superparamagnetic properties, superparamagnetic iron oxide nanoparticles (SPIOs) are widely used for the applications in the field of biomedicine, including tissue engineering and regenerative medicine. However, the regulation of SPIOs on the gene expressions in the stem cells is not clear. Methods: In this study, by RNA-Seq analysis, we analyzed the gene expression pattern in the neural stem cells (NSCs) treated with SPIOs in the presence or absence of static magnetic field (SMF). Results: It was found that SPIOs with SMF regulated more gene expression in NSCs, while most of these genes have been previously reported to play a crucial role in NSCs fate decision. Conclusions: Our findings reveal the ability of SPIOs and SMF in the regulation of gene expression in NSCs, which may provide an experimental basis for its applications.

New Approaches in Synthesis and Characterization Methods of Iron Oxide Nanoparticles

Recent years have witnessed an extensive application of iron oxide nanoparticles within a wide variety of fields, including drug delivery, hyperthermia, biosensing, theranostics, and cell and molecular separation. Consequently, synthesis and characterization methods have continuously evolved to provide the possibility for controlling the physico-chemical and biological properties of the nanoparticles to better suit the envisaged applications. In this manner, this chapter aims to provide an extensive overview of the most recent progress made within the processes of iron oxide nanoparticle synthesis and characterization. Thus, the chapter will focus on novel and advanced approaches reported in the literature for obtaining standardized nanoparticles with controllable properties and effects. Specifically, it will emphasize the most recent progress made within the microwave-assisted, microfluidics, and green synthesis methods, as they have shown higher capacities of controlling the outcome nanoparticle properties.

IGF-1 Conjugated Sub-5 nm Ultrafine Iron Oxide Nanoparticle Enhances Targeted Drug Delivery and Efficacy of DNA Topoisomerase Inhibitor SN38 for Pancreatic Cancer: An in Vitro Study

Background Pancreatic cancer remains one of the most lethal cancers largely due to the inefficient delivery of therapeutics. Nanomaterials have been extensively investigated as drug delivery platforms, showing improved drug pharmacodynamics and pharmacokinetics. However, their applications in pancreatic cancer have not yet been successful due to limited tumor delivery caused by dense tumor stroma and distorted tumor vasculatures. Meanwhile, smaller-sized nanomaterials have shown improved tumor delivery and retention in various tumors, including pancreatic tumors, suggesting their potential in enhancing drug delivery. Methods An ultrafine iron oxide nanoparticle (uIONP) was used to encapsulate 7-ethyl-10-hydroxyl camptothecin (SN38), the water-insoluble active metabolite of chemotherapy drug irinotecan for treating pancreatic cancer in clinic. Insulin-like growth factor 1 (IGF-1) was conjugated to uIONP as a ligand for targeting pancreatic cancer and stromal cells overexpressing IGF-1 receptor (IGF1R). The SN38 loading and release profile were characterized. The cancer cell targeting and induced apoptosis by developed nano-formulationIGF1-uIONP/SN38 were also investigated. Results IGF1-uIONP/SN38 demonstrated stable drug loading in physiological pH with the loading efficiency of 68.2 ± 3.5% (SN38/Fe, wt%) and <7% release for 24 hours. In tumor-interstitial- and lysosomal-mimicking pH (6.5 and 5.5), 52.2 and 91.3% of encapsulated SN38 were released over 24 hours. The IGF1-uIONP/SN38 exhibited specific receptor-mediated cell targeting and cytotoxicity to MiaPaCa-2 cells with IC50 of 11.8 ± 2.3 nM, but not to HEK293 human embryonic kidney cells. Conclusion The IGF1-uIONP significantly improved the delivery of SN38 to targeted pancreatic cancer cells, holding the potential for in vivo theranostic applications.

Single-Atom Fe-Anchored Nano-Diamond With Enhanced Dual-Enzyme Mimicking Performance for H2O2 and Glutathione Detection

Glutathione (GSH) is an important antioxidant and free radical scavenger that converts harmful toxins into harmless substances and excretes them out of the body. In the present study, we successfully prepared single-atom iron oxide-nanoparticle (Fe-NP)-modified nanodiamonds (NDs) named Fe-NDs via a one-pot in situ reduction method. This nanozyme functionally mimics two major enzymes, namely, peroxidase and oxidase. Accordingly, a colorimetric sensing platform was designed to detect hydrogen peroxide (H2O2) and GSH. Owing to their peroxidase-like activity, Fe-NDs can oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue with sufficient linearity at H2O2 concentrations of 1–60 μM and with a detection limit of 0.3 μM. Furthermore, using different concentrations of GSH, oxidized TMB can be reduced to TMB, and the color change from blue to nearly colorless can be observed by the naked eye (linear range, 1–25 μM; detection limit, 0.072 μM). The established colorimetric method based on oxidase-like activity can be successfully used to detect reduced GSH in tablets and injections with good selectivity and high sensitivity. The results of this study exhibited reliable consistency with the detection results obtained using high-performance liquid chromatography (HPLC). Therefore, the Fe-NDs colorimetric sensor designed in this study offers adequate accuracy and sensitivity.

A Review of Microbial Mediated Iron Nanoparticles (IONPs) and Its Biomedical Applications

Nanotechnology is a booming avenue in science and has a multitude of applications in health, agriculture, and industry. It exploits materials’ size at nanoscale (1–100 nm) known as nanoparticles (NPs). These nanoscale constituents are made via chemical, physical, and biological methods; however, the biological approach offers multiple benefits over the other counterparts. This method utilizes various biological resources for synthesis (microbes, plants, and others), which act as a reducing and capping agent. Among these sources, microbes provide an excellent platform for synthesis and have been recently exploited in the synthesis of various metallic NPs, in particular iron. Owing to their biocompatible nature, superparamagnetic properties, small size efficient, permeability, and absorption, they have become an integral part of biomedical research. This review focuses on microbial synthesis of iron oxide nanoparticles using various species of bacteria, fungi, and yeast. Possible applications and challenges that need to be addressed have also been discussed in the review; in particular, their antimicrobial and anticancer potentials are discussed in detail along with possible mechanisms. Moreover, some other possible biomedical applications are also highlighted. Although iron oxide nanoparticles have revolutionized biomedical research, issues such as cytotoxicity and biodegradability are still a major bottleneck in the commercialization of these nanoparticle-based products. Addressing these issues should be the topmost priority so that the biomedical industry can reap maximum benefit from iron oxide nanoparticle-based products.

Green Synthesis of Iron Oxide Nanoparticle Using Coffee Seed Extract and Its Antibacterial Activity

The discovery of reliable and green processes for metal oxide nanoparticles synthesis is particularly crucial and exhibits huge potential in various applications. Thus, in this paper, a fast, single step and environmental-friendly method to synthesize iron oxide nanoparticles (Fe2O3-NPs) by bio-reduction of iron salts Fe2+ and Fe3+ under the presence of coffee seeds (CS) aqueous extract was demonstrated. The characteristics of the synthesised Fe2O3-NPs were investigated by using X-ray diffraction (XRD) and ultraviolet-visible (UV-Vis) spectrophotometry techniques. The XRD result revealed that the Fe2O3-NPs produced display highly crystalline property with a cubic structure and the average size of the resulted particle is ranging from 23.2 nm to 37.5 nm. Additionally, the energy band gap (Eg) calculated also showed that maghemite (γ-Fe2O3) nanoparticles was successfully synthesised by using CS extract. The resulted nanoparticles are highly feasible in the inhibition of the growth of pathogenic microorganism.

The Investigation of Mixed Ferrofluids Containing Iron Oxide nanoparticles and Microspheres

The aim of the present work is the synthesis and characterization of iron oxide (Fe3O4) nanoparticles. These nanoparticles are coated with oleic acid and polyvinyl butyral and mixed with microspheres and further developed ferrofluids with silicon oil. Studies of the performance of the nanoparticles in these ferrofluids with and without coating agents were carried out. The nanoparticles were synthesized using the chemical co-precipitation technique and coated with oleic acid and polyvinyl butyral, and it further mixed with microsphere ferrofluids and developed using silicon oil. The prepared Fe3O4 nanoparticles and their coated forms of oleic acid and polyvinyl butyral were mixed with microspheres; furthermore, ferrofluids were developed with silicon oil. All forms of these ferrofluids are characterized for morphology and phase purity (SEM, XRD, and FTIR). The iron oxide (Fe3O4) nanoparticles have shown different magnetic properties, differentiating macroscopic iron oxide in suspended particles. The ratio of surface to volume increases along with the decrease in atomic size, essential for assessing the surface morphological properties. The magneto-rheological (MR) fluids were determined, and shear stress of Expancel microsphere mixed iron oxide nanoparticle with and without them was found almost equal. However, the ferrofluid with PVB coated nanoparticles and microspheres emerged as a stable rheological ferrofluid, sustaining high shear stress and low viscosity with increasing shear rate. Also, shear rates up to 650 s−1 have been observed, showing very high shear stress withstanding capacity. The stability and performance of the magnetic colloidal ferrofluids depend on the thermal contribution and the balance between attractive/repulsive interactions.

Ultrasonic Imaging of Carotid Inflammatory Plaque with Superparamagnetic Nanoparticles

Chronic inflammation can stimulate the formation and progression of atherosclerotic plaques and increase the vulnerability of plaques. However, there are few studies on the changes of carotid inflammatory plaques during treatment. Our study attempted to investigate the use of superparamagnetic iron oxide nanoparticle (SPION) ultrasound imaging to detect the expression of vascular cell adhesion molecule-1 (VCAM-1) in patients with carotid plaques and analyze the effects of SPION ultrasound imaging in inflammatory plaque visualization effect. SPION microbubble contrast agents have good imaging effects both in vivo and in vitro. We conjugated the VCAM-1 protein to the microbubbles wrapped in SPIONs to form SPIONs carrying VCAM-1 antibodies. Observe the signal intensity of SPIONs carrying VCAM-1 antibody to arteritis plaque. The results showed that the SPION contrast agent carrying VCAM-1 antibody had higher peak gray-scale video intensity than the other two groups of contrast agents not carrying VCAM-1 antibody. It shows that SPIONs have excellent imaging effects in ultrasound imaging, can evaluate the inflammatory response of arterial plaque lesions, and are of great significance for the study of carotid inflammatory plaque changes.