Silica-coated Iron Oxide Nanoparticles Research Articles

Investigation of silica coated iron oxide nanoparticles and activated carbon as a potential fluid loss additive and Pakistan shale inhibitor in water-based mud system coupled with advance image processing technique

Investigation of silica coated iron oxide nanoparticles and activated carbon as a potential fluid loss additive and Pakistan shale inhibitor in water-based mud system coupled with advance image processing technique

Design, Synthesis, and Evaluation of Novel Magnetic Nanoparticles Combined with Thiophene Derivatives for the Removal of Cr(VI) from an Aqueous Solution.

Most heavy metals are harmful to human health and the environment, even at extremely low concentrations. In natural waters, they are usually found only in trace amounts. Researchers are paying great attention to nanotechnology and nanomaterials as viable solutions to the problem of water pollution. This research focuses on the synthesis of organic thiophene derivatives that can be used as grafted ligands on the surface of silica-coated iron oxide nanoparticles to remove Cr(VI) chromium ions from water. The Vilsmeier-Haack reaction allows the formation of aldehyde groups in thiophene derivatives, and the resulting products were characterized by the FT-IR, NMR, and GC-MS. Schiff base is used as a binder between organic compounds and nanoparticles by the reaction of aldehyde groups in thiophene derivatives and amine groups on the surface of coated iron oxide nanoparticles. Schiff base functionalized Fe3O4 composites (MNPs@SiO2-SB-THCA) and (MNPs@SiO2-SB-THCTA) were successfully synthesized by homogeneous and heterogeneous methods and characterized by a combination of FT-IR, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The adsorption studies, kinetic modeling, adsorption isotherms, and thermodynamics of the two materials, MNPs@SiO2-SB-THCA and MNPs@SiO2-SB-THCTA, were investigated for the removal of Cr(VI) from water at room temperature and at 50 mg/L. The high adsorption capacity at pH 6 for MNPs@SiO2-SB-THCTA was 15.53 mg/g, and for MNPs@SiO2-SB-THCA, it was 14.31 mg/g.

Synthesized silica-coated iron oxide nanoparticles and its application as rheology modifier in water-based drilling fluid

Synthesized silica-coated iron oxide nanoparticles and its application as rheology modifier in water-based drilling fluid

Thermomechanical stress analyses of nanowarming-assisted recovery from cryopreservation by vitrification in human heart and rat heart models.

This study investigates thermomechanical stress in cryopreservation by vitrification of the heart, while exploring the effects of nanowarming-assisted recovery from cryogenic storage. This study expands upon a recently published study, combining experimental investigation and thermal analysis of cryopreservation on a rat heart model. Specifically, this study focuses on scenarios with variable concentrations of silica-coated iron-oxide nanoparticles (sIONPs), while accounting for loading limitations associated with the heart physiology, as well as the properties of cryoprotective agent (CPA) solution and the geometry of the container. Results of this study suggest that variable sIONP concentration based on the heart physiology will elevate mechanical stresses when compared with the mathematically simplified, uniform distribution case. The most dangerous part of rewarming is below glass transition and at the onset of nanowarming past the glass transition temperature on the way for organ recovery from cryogenic storage. Throughout rewarming, regions that rewarm faster, such as the chambers of the heart (higher sIONP concentration), undergo compressive stresses, while the slower rewarming regions, such as the heart myocardium (low sIONP concentration), undergo tension. Being a brittle material, the vitrified organ is expected to fail under tension in lower stresses than in compression. Unfortunately, the location and magnitude of the maximum stress in the investigated cases varied, while general rules were not identified. This investigation demonstrates the need to tailor the thermal protocol of heart cryopreservation on a case-by-case basis, since the location, orientation, magnitude, and instant at which the maximum mechanical stress is found cannot be predicted a priori. While thermomechanical stress poses a significant risk to organ integrity, careful design of the thermal protocol can be instrumental in reducing the likelihood of structural damage, while taking full advantage of the benefits of nanowarming.

Nanowarming improves survival of vitrified ovarian tissue and follicular development in a sheep model

Tissue cryopreservation has allowed long term banking of biomaterials in medicine. Ovarian tissue cryopreservation in particular helps patients by extending their fertility window. However, protection against tissue injury during the thawing process has proven to be challenging. This is mainly due to the heterogenous and slow distribution of the thermal energy across the vitrified tissue during a conventional warming process. Nanowarming is a technique that utilizes hyperthermia of magnetic nanoparticles to accelerate this process. Herein, hyperthermia of synthesized PEGylated silica-coated iron oxide nanoparticles was used to deter the injury of cryopreserved ovarian tissue in a sheep model. When compared to the conventional technique, our findings suggest that follicular development and gene expression in tissues warmed by the proposed technique have been improved. In addition, Nanowarming prevented cellular apoptosis and oxidative stress. We therefore conclude that Nanowarming is a potential complementary candidate to increase efficiency in the ovarian cryopreservation field.

Experimental investigation of rheological behaviour and stability of mud system using novel image processing application in presence of activated carbon and silica-coated iron oxide nanoparticles

Experimental investigation of rheological behaviour and stability of mud system using novel image processing application in presence of activated carbon and silica-coated iron oxide nanoparticles

Insight into the photothermal therapeutic impacts of silica-coated iron oxide nanocomposites

Recently, near-infrared photothermal therapy combined with targeted nano-sensitizer has been used for cancer eradication as it protects the surrounding tissues. Although iron oxide nanoparticles (INPs) are efficient photo-heat conversion agents, they tend to agglomerate, restricting their utility in medical applications. We prepared silica-coated INPs (SCINPs) to overcome this obstacle. The physical properties of INPs and SCINPs were evaluated using transmission electron microscope (TEM), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), atomic force microscope (AFM) and X-RAY diffraction (XRD). The polydispersity index (PDI) value was 0.21 and 0.44 for INPs and SCINPs, respectively. Zeta potential measurements showed that the prepared nanoparticles had negative net surface charges with average values of −28 ± 4.21 and −48 ± 5 mv for INPs and SCINPs, respectively. This is a pioneered study that evaluate the photothermal therapeutic effect of silica coated iron oxide nanoparticles. In addition to evaluate their photothermal therapeutic effect, as nano photothermal agents, using comet assay and oxidative stress parameters. Also, their photothermal therapeutic effect were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Photothermal assessment indicated that SCINPs could improve the photothermal therapy (PTT) because of their reproducible hyper-thermic and hypo-thermic effects with repeated treatment. Compared to INPs, SCINPs significantly improved the photothermal therapeutic behavior in treated cells by around 1.88 folds. SCINPs were more effective photothermal therapeutic agents and had considerable potential as novel therapeutic agents.

Fine-Tuning of Particle Size and Morphology of Silica Coated Iron Oxide Nanoparticles

Due to their unique properties such as superparamagnetism, easy surface functionalization, and colloidal stability among others, silica coated iron oxide nanoparticles (SIONPs) have received remarkable attention for biomedical applications such as in diagnostics or therapeutics. Tuning the particle size and size distribution of SIONPs as a function of solvent, catalyst, silica precursor, etc., in a modified Stöber’s method has been extensively studied. However, there has been no concerted effort to study the effect of the above parameters along with the surface chemistry of the iron oxide nanoparticles (IONPs) on the morphologies obtained and hence the resultant magnetic properties. Here, we report an in-depth investigation of the nature of solvent, concentration of catalyst, mass ratio of IONPs to silica precursor and surface groups of IONPs on the size and resultant morphology of SIONPs. We report here for the first time the evolution of different morphologies, namely, fused, irregular, aggregate, and spherical morphologies, by careful control of the reaction conditions. Controlling the sizes and morphologies exerts an influential effect on the resultant magnetic properties and, thus, their applications downstream.

Biocompatible fluorescent europium(iii) magnetic nanoparticles

Silica-coated iron oxide and silica nanoparticles were prepared and derivatized with a Eu(iii) complex to yield magneto-fluorescent and fluorescent nanomaterials that could work as possible biosensors.

Cryopreservation of Whole Rat Livers by Vitrification and Nanowarming.

Liver cryopreservation has the potential to enable indefinite organ banking. This study investigated vitrification-the ice-free cryopreservation of livers in a glass-like state-as a promising alternative to conventional cryopreservation, which uniformly fails due to damage from ice formation or cracking. Our unique "nanowarming" technology, which involves perfusing biospecimens with cryoprotective agents (CPAs) and silica-coated iron oxide nanoparticles (sIONPs) and then, after vitrification, exciting the nanoparticles via radiofrequency waves, enables rewarming of vitrified specimens fast enough to avoid ice formation and uniformly enough to prevent cracking from thermal stresses, thereby addressing the two main failures of conventional cryopreservation. This study demonstrates the ability to load rat livers with both CPA and sIONPs by vascular perfusion, cool them rapidly to an ice-free vitrified state, and rapidly and homogenously rewarm them. While there was some elevation of liver enzymes (Alanine Aminotransferase) and impaired indocyanine green (ICG) excretion, the nanowarmed livers were viable, maintained normal tissue architecture, had preserved vascular endothelium, and demonstrated hepatocyte and organ-level function, including production of bile and hepatocyte uptake of ICG during normothermic reperfusion. These findings suggest that cryopreservation of whole livers via vitrification and nanowarming has the potential to achieve organ banking for transplant and other biomedical applications.

A highly efficient protein corona-based proteomic analysis strategy for the discovery of pharmacodynamic biomarkers

The composition of serum is extremely complex, which complicates the discovery of new pharmacodynamic biomarkers via serum proteome for disease prediction and diagnosis. Recently, nanoparticles have been reported to efficiently reduce the proportion of high-abundance proteins and enrich low-abundance proteins in serum. Here, we synthesized a silica-coated iron oxide nanoparticle and developed a highly efficient and reproducible protein corona (PC)-based proteomic analysis strategy to improve the range of serum proteomic analysis. We identified 1,070 proteins with a median coefficient of variation of 12.56% using PC-based proteomic analysis, which was twice the number of proteins identified by direct digestion. There were also more biological processes enriched with these proteins. We applied this strategy to identify more pharmacodynamic biomarkers on collagen-induced arthritis (CIA) rat model treated with methotrexate (MTX). The bioinformatic results indicated that 485 differentially expressed proteins (DEPs) were found in CIA rats, of which 323 DEPs recovered to near normal levels after treatment with MTX. This strategy can not only help enhance our understanding of the mechanisms of disease and drug action through serum proteomics studies, but also provide more pharmacodynamic biomarkers for disease prediction, diagnosis, and treatment.

Fabrication of a Double Core-Shell Particle-Based Magnetic Nanocomposite for Effective Adsorption-Controlled Release of Drugs.

There has been very limited work on the control loading and release of the drugs aprepitant and sofosbuvir. These drugs need a significant material for the control of their loading and release phenomenon that can supply the drug at its target site. Magnetic nanoparticles have characteristics that enable them to be applied in biomedical fields and, more specifically, as a drug delivery system when they are incorporated with a biocompatible polymer. The coating with magnetic nanoparticles is performed to increase efficiency and reduce side effects. In this regard, attempts are made to search for suitable materials retaining biocompatibility and magnetic behavior. In the present study, silica-coated iron oxide nanoparticles were incorporated with core–shell particles made of poly(2-acrylamido-2-methylpropane sulfonic acid)@butyl methacrylate to produce a magnetic composite material (MCM-PA@B) through the free radical polymerization method. The as-prepared composite materials were characterized through Fourier-transform infrared (FTIR)spectroscopy, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), energy-dispersive X-Ray Analysis (EDX), and thermogravimetric analysis (TGA), and were further investigated for the loading and release of the drugs aprepitant and sofosbuvir. The maximum loading capacity of 305.76 mg/g for aprepitant and 307 mg/g for sofosbuvir was obtained at pH 4. Various adsorption kinetic models and isotherms were applied on the loading of both drugs. From all of the results obtained, it was found that MCM-PA@B can retain the drug for more than 24 h and release it slowly, due to which it can be applied for the controlled loading and targeted release of the drugs.

Vitrification and Rewarming of Magnetic Nanoparticle-Loaded Rat Hearts.

To extend the preservation of donor hearts beyond the current 4-6 h, this paper explores heart cryopreservation by vitrification-cryogenic storage in a glass-like state. While organ vitrification is made possible by using cryoprotective agents (CPA) that inhibit ice during cooling, failure occurs during convective rewarming due to slow and non-uniform rewarming which causes ice crystallization and/or cracking. Here an alternative, "nanowarming", which uses silica-coated iron oxide nanoparticles (sIONPs) perfusion loaded through the vasculature is explored, that allows a radiofrequency coil to rewarm the organ quickly and uniformly to avoid convective failures. Nanowarming has been applied to cells and tissues, and a proof of principle study suggests it is possible in the heart, but proper physical and biological characterization especially in organs is still lacking. Here, using a rat heart model, controlled machine perfusion loading and unloading of CPA and sIONPs, cooling to a vitrified state, and fast and uniform nanowarming without crystallization or cracking is demonstrated. Further, nanowarmed hearts maintain histologic appearance and endothelial integrity superior to convective rewarming and indistinguishable from CPA load/unload control hearts while showing some promising organ-level (electrical) functional activity. This work demonstrates physically successful heart vitrification and nanowarming and that biological outcomes can be expected to improve by reducing or eliminating CPA toxicity during loading and unloading.

Silica-Coated Iron Oxide Nanoparticles for DNA Isolation for Molecular Genetic Studies in Hematology.

Aim: To develop magnetic nanoparticles (MNPs) based on iron oxide for DNA isolation from blood cells for quantitative molecular genetic analyses of the V617F mutation in the Januskinase 2 (JAK2) gene. Materials and Methods: MNPs were synthesized by the coprecipitation method and coated with tetraethyl orthosilicate (TEOS). The size and shape of the complexes were estimated using transmission electron microscopy. Twenty blood samples from patients with myeloproliferative disorders were used for DNA isolation with the MNPs. DNA quality and compatibility for molecular genetic studies of the JAK2 V617F mutation were investigated by gel electrophoresis and real-time polymerase chain reaction (RT-PCR). Results: The average amount of DNA isolated from 150 μL of whole blood was 75.2 ng when MNPs were used and 72.5 ng when standard silica sorbent was used. There was no DNA damage observed after interaction with MNPs. RT-PCR demonstrated similar values for the JAK2 V617F mutant DNA ratios in the samples after DNA isolation with MNPs and by standard sorption on silica. Conclusions: MNPs with silicate capsules of sufficient thickness were obtained and the undesirable damaging effect of iron oxides on nucleic acids during isolation from cells were eliminated. Designed MNPs allow obtaining intact DNA for molecular genetic studies using the example of the JAK2 V617F for study.

Vitrification and Nanowarming of Kidneys.

Vitrification can dramatically increase the storage of viable biomaterials in the cryogenic state for years. Unfortunately, vitrified systems ≥3 mL like large tissues and organs, cannot currently be rewarmed sufficiently rapidly or uniformly by convective approaches to avoid ice crystallization or cracking failures. A new volumetric rewarming technology entitled “nanowarming” addresses this problem by using radiofrequency excited iron oxide nanoparticles to rewarm vitrified systems rapidly and uniformly. Here, for the first time, successful recovery of a rat kidney from the vitrified state using nanowarming, is shown. First, kidneys are perfused via the renal artery with a cryoprotective cocktail (CPA) and silica‐coated iron oxide nanoparticles (sIONPs). After cooling at −40 °C min−1 in a controlled rate freezer, microcomputed tomography (µCT) imaging is used to verify the distribution of the sIONPs and the vitrified state of the kidneys. By applying a radiofrequency field to excite the distributed sIONPs, the vitrified kidneys are nanowarmed at a mean rate of 63.7 °C min−1. Experiments and modeling show the avoidance of both ice crystallization and cracking during these processes. Histology and confocal imaging show that nanowarmed kidneys are dramatically better than convective rewarming controls. This work suggests that kidney nanowarming holds tremendous promise for transplantation.

Fluorescein-entrapped magnetosomes for magnetically assisted photodynamic therapy.

Aim: We investigated the application of fluorescein (FL)-entrapped magnetosomes, in other words, silica-coated iron oxide nanoparticles entrapped within niosomes (SIO/NIO), in magnetically assisted photodynamic therapy (PDT) in vitro. Methods: Panc-1 cells were treated with the magnetosomes, with and without external magnetic guidance, and irradiated with blue light. Results & conclusion: Upon photoactivation, the FL-entrapped magnetosomes can produce higher singlet oxygen in comparison to FL-entrapped micelles, probably due to the higher release tendency of the photosensitizer from the former. In vitro studies in Panc-1 cells revealed magnetically assisted enhancement in the cellular uptake of the magnetosomes. Magnetic assistance also led to enhancement in PDT efficiency in cells treated with the FL-entrapped magnetosomes and light, thus highlighting their potential in PDT.

Simultaneous extraction of six phthalic acid esters from polyethylene terephthalate (PET) bottled water using poly (ionic liquid) functionalised silica coated-iron oxide nanoparticles: a risk assessment study

ABSTRACT In this research, a poly (ionic liquid) functionalised silica-coated magnetic nanoparticles were synthesised for the first time and utilised as a novel adsorbent for the simultaneous extraction of six phthalic acid esters from polyethylene terephthalate bottled drinking water samples. The adsorbent was prepared by grafting poly (1-benzyl-3-vinyl-1 H-imidazol-3-ium chloride) onto silica-coated Fe3O4nanoparticles via Cu(0)-mediated reversible-deactivation radical polymerisation method. Various techniques were used to characterise the synthesised nanomaterials. A qualitative analysis was performed using ultra-performance liquid chromatography triple–quadrupole tandem mass spectrometry. Response surface methodology based on central composite design was used to optimise the extraction procedure and the optimised condition for each factor was; pH of3.9, 22 mg of adsorbent, 3.5 min extraction time, 3 min desorption time, 340 µL of elution solvent (methanol).The results of the validation of the method indicated its acceptable accuracy (88.6-100.1%), good linearity (r > 0.995), satisfactory repeatabilities (RSDs ≤ 6% for intra- and inter–day precisions) and high enrichment factors (535–572). The limits of detection and limits of quantification of the proposed method achieved were 1.1-4.6 ngL–1and 3.6-15.3 ngL–1, respectively. In this study, six common PAEs, including dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis (2-ethylhexyl) phthalate, and di-n–octyl phthalate, were found in PET bottled water within the range of 0.21-0.94 μgL–1, under different storage conditions. Nevertheless, only a negligible risk is caused by the PAEs in PET bottled water for consumers following the recommendations, such as storing at a common place (25°C), in a short period away from the sun.

PVP Surface-protected silica coated iron oxide nanoparticles for MR imaging application

This paper proposed an engineered mesoporous silica-coated Fe3O4 nanoparticle, PVPMSFe, prepared by a sol-gel/surface-protected etching mechanism as an MRI T2 contrast agent. To this end, the structural characterization of the nanocomposite was performed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, VSM, thermogravimetric analysis (TGA), TEM, FESEM, and energy-dispersive X-ray scanning electron microscopy (EDS). The findings show that the synthesized nanocomposite has a mesoporous structure with an average particle size of 11.8 nm and excellent magnetization properties. The biocompatibility of PVPMSFe was investigated by MTT assay and hemolysis assay of red blood cells and the results indicate that PVPMSFe has favorable biocompatibility. Besides, the effect of PVPMSFe was assessed with MRI relaxivity measurement (T2 signal). Regarding the in vitro MRI relaxivity measurements outputs (r2 =144.4), PVPMSFe can attenuate the T2 signal of MRI, perfectly which makes it an efficient T2 contrast agent.

Preparation and Characterization of Silica-Coated Iron Oxide Nanoparticles (Fe3O4@SiO2 NPs)

In this study, this SiO2 has been coated on the surface of Fe3O4 (Fe3O4@SiO2) by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) under alkaline medium at 80oC. It was found that only 500 mL TEOS is required to obtain the best coated Fe3O4 core structures which has been confirmed from its TEM micrograph. FTIR analyses revealed the formation of Si-O-Si bonds at 1084.2–1101.4 cm-1 hence confirmed that SiO2 has been successfully coated the Fe3O4 core. From the FESEM analyses, the average size of silica was ~ 50 -70 nm. EDX of the Fe3O4@SiO2 showed that silica had been effectively bonded onto the surface of Fe3O4. The VSM measurements confirmed the superparamagnetic properties of Fe3O4@SiO2 that is desirable for biomedical applications.

In vivo MRI detection of intraplaque macrophages with biocompatible silica-coated iron oxide nanoparticles in murine atherosclerosis.

Identification of a vulnerable atherosclerotic plaque before rupture is an unmet clinical need. Integrating nanomedicine with multimodal imaging has the potential to precisely detect biological processes in atherosclerosis. We synthesized silica-coated iron oxide nanoparticles (SIONs) coated with rhodamine B isothiocyanate and polyethylene glycol and investigated their feasibility in the detection of macrophages in inflamed atherosclerotic plaques of apolipoprotein E-deficient (ApoE-/-) mice via magnetic resonance (MR) and fluorescence reflectance (FR) imaging. In vitro cellular uptake of SIONs was assessed in macrophages using confocal laser scanning microscopy (CLSM). In vivo MR imaging was performed 24 h after SION injection via the tail vein in 26-week-old ApoE-/- mice fed a high-cholesterol diet (HCD). We also performed FR imaging of the extracted aortas from four different mice: two normal-diet-fed C57BL/6 mice injected with saline or 10 mg/kg SIONs and two HCD-fed ApoE-/- mice injected with 5 or 10 mg/kg SIONs. The harvested aortas were cryosectioned and stained with immunohistochemical staining. The CLSM images at 24 h after incubation showed efficient uptake of SIONs by macrophages, with no evidence of cytotoxicity. The in vivo and ex vivo MR and FR images demonstrated SION deposition in the atheroma. Upon immunohistochemical staining of the aorta, CLSM images revealed colocalization of macrophages and SIONs in the atherosclerotic plaque. These results demonstrate that polyethylene glycosylated SIONs could be a highly effective method to identify macrophage activity in atherosclerotic plaques as a multimodal imaging agent.