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Many available chemotherapeutic methods are faced with multiple challenges that range from therapeutic failure to detrimental adverse or toxicity effects. Most of the drugs have low efficacy due to low capability to target specific diseased tissues, minimal biocompatibility and low bioavailability. As a result, they are burden to patients by inducing drug resistance, economic losses and even death. The discovery and utilization of nano-based drug carriers such as superparamagnetic iron oxide nanoparticles (SPIONs) in drug delivery system (DDS) has been a great achievement for overcoming the pre-existing challenges. After properly coated and appropriately functionalized, they exhibit extensive drug-loading capacity and are able to be circulated in the blood stream without causing immune provocation before achieving the desired therapeutic effects by delivering drug specifically to the targeted site. Furthermore, they can be remotely controlled to release drugs using appropriate stimuli. Therefore, this review has explained important aspects about the utilization of SPIONs as a novel nano-vector for DDS, focusing on their post-synthetic surface modification, functionalization, drug loading and release. This work is potential as it provides a framework into the applications of SPIONs in theranostics of challenging diseases such as cancer by laying down the basic principles of SPION applications in biomedical field. [ABSTRACT FROM AUTHOR]

Surface derivatized magnetic nanoparticles have been commonly used for magnetic separation. Facile mechanisms are needed to be developed for the design of bio-functionalized magnetic hybrid materials, where the surfaces can be re-generated for the re-use of the developed platforms. Superparamagnetic iron oxide nanoparticles with a diameter below 10 nm were synthesized via a novel microwave-assisted hydrothermal method in the presence of citrate ions, which allowed to obtain uniform and negatively charged nanoparticles. These were then coupled with Poly-l-lysine (PLL), forming micrometer-sized self-assembled spherical entities. Cross-linking the PLL within these microspheres with glutaraldehyde stabilized them chemically and mechanically. The active bio-functionality was introduced by a protein grafting methodology, using m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester (SMBS). The Moringa oleifera Coagulant Protein (MOCP) from a seed extract was employed for its characteristic coagulation activity. The performance of the MOCP functionalized microspheres was evaluated as a function of turbidity removal of problematic colloidal clay from water via magnetic separation, resulting in over 80% of activity within 15 min. Surface of these hybrid materials can be re-generated by treatment with alcohol, allowing their easy magnetic separation and re-use. The rapid and strong response with tunable magnetic property makes these hybrid microspheres a powerful tool for many potential applications, due to the general applicability of the developed methodology. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs) were investigated owing to their potential relaxometric properties for magnetic resonance imaging (MRI) applications. For this purpose, shape- and size-controlled SPIONs were prepared using various reducing agents via a facile chemical coprecipitation method. The optimization of reaction parameters such as stirring rate, temperature, reaction time, and pH was carried out to study the particle's growth, size, and shape of nanoparticles (NPs). Transmission electron microscopy (TEM) images reveal that the spherical (9.1 ± 1.5 nm)- and cubic (11.7 ± 1.8 nm)-shaped NPs were attained using NH4OH and NaOH as reducing agents, respectively. X-ray diffraction (XRD) analysis of as-synthesized SPIONs shows the formation of magnetite (Fe3O4) phase having cubic inverse spinel structure. The various oxidation states of Fe were investigated via X-ray photoelectron spectroscopy (XPS) by analyzing Fe 2p spectra of SPIONs. The magnetic character and chemical stability of SPIONs were monitored in the synthetic seawater (SW) having salinity 36.03 g L−1; which is the critical requirement for oil reservoir applications. Spin–spin (T2) relaxation signals were attained using miniaturized Acorn Area analyzer to determine the relaxometric properties. The transverse relaxivities (r2) for MNP–NH4OH (41.0 mM−1 s−1) and MNP–NaOH (28.5 mM−1 s−1) were 2.11 and 1.47 times higher than MNP–KOH (19.4 mM−1 s−1), respectively. This study affirms that by controlling the reaction parameters, we can selectively design Fe3O4 NPs of desired size and shape, which give enhanced T2-relaxation and excellent relaxivity properties in SW for potential MRI applications associated with oil reservoirs. [ABSTRACT FROM AUTHOR]

The versatility of superparamagnetic iron-oxide nanoparticles (SPIONs) have been extensively investigated, especially for their applications in therapeutics and diagnostics. Considering their intriguing feature of contrasting agent, in terms of medical applications, it is still in its infancy. Various physicochemical parameters like magnetism, crystallinity, and optical parameters contribute to their better contrasting agent. In this study, SPIONs were synthesized with different concentrations of precursor iron molecular solution in the presence of magnetic field and the optimum concentration of precursor iron molecular solution was determined as 0.133%. SPIONs obtained at optimum concentration were further analyzed by both microscopic and spectroscopic analysis. The difference occurred in the elemental nature of SPIONs as they were synthesized in the magnetic field out of precursor iron molecular solution was analyzed with a specific reference to NMR spectroscopy. SPIONs as contrasting agent against X-ray imaging was also investigated in quail's egg. [ABSTRACT FROM AUTHOR]