Functionalized Iron Oxide Nanoparticles Research Articles

Electrochemical technique to develop surface-controlled polyaniline nano-tulips (PANINTs) on PCL-reinforced chitosan functionalized (CS-f-Fe2O3) scaffolds for stimulating osteoporotic bone regeneration

Bone defects pose significant challenges in orthopedic surgery, often leading to suboptimal outcomes and complications. Addressing these challenges, we employed a three-electrode electrochemical system to fabricate surface-controlled polyaniline nano-tulips (PANINTs) decorated polycaprolactone (PCL) reinforced chitosan functionalized iron oxide nanoparticles (CS-f-Fe2O3) scaffolds. These structures were designed to emulate the natural extracellular matrix (ECM) and promote enhanced osseointegration by establishing a continuous interface between host bone and graft, thereby improving both biological processes and mechanical stability. In vitro experiments demonstrated that PANINTs-PCL/CS-f-Fe2O3 substrates significantly promoted the proliferation, differentiation, and spontaneous outgrowth and extension of MC3T3-E1 cell activity. The nanomaterials exhibited increased cell viability and osteogenic differentiation, as evidenced by elevated expression of bone-related markers such as ALP, ARS, COL-I, RUNX2, and SPP-I, as determined by qRT-PCR. Our findings underscore the regenerative potential of in situ cell culture systems for bone defects, emphasizing the targeted stimulation of essential cell subpopulations to facilitate rapid bone tissue regeneration.

Self-Healing Iron Oxide Polyelectrolyte Nanocomposites: Influence of Particle Agglomeration and Water on Mechanical Properties

Self-healing nanocomposites can be generated by organic functionalization of inorganic nanoparticles and complementary functionalization of the polymer matrix, allowing reversible interactions between the two components. Here, we report on self-healing nanocomposites based on ionic interactions between anionic copolymers consisting of di(ethylene glycol) methyl ether methacrylate, sodium 4-(methacryloyloxy)butan-1-sulfonate, and cationically functionalized iron oxide nanoparticles. The materials exhibited hygroscopic behavior. At water contents < 6%, the shear modulus was reduced by up to 90%. The nanoparticle concentration was identified as a second factor strongly influencing the mechanical properties of the materials. Backscattered scanning electron microscopy and small-angle X-ray scattering measurements showed the formation of agglomerates in the size range of 100 nm to a few µm in diameter, independent of concentration, resulting in the disordering of the semi-crystalline ionic polymer blocks. These effects resulted in an increase in the shear modulus of the composite from 3.7 MPa to 5.6 MPa, 6.3 Mpa, and 7.5 MPa for 2, 10, and 20 wt% particles, respectively. Temperature-induced self-healing was possible for all composites investigated. However, only 36% of the maximum stress could be recovered in systems with a low nanoparticle content, whereas the original properties were largely restored (>85%) at higher particle contents.

Functionalized iron oxide nanoparticles for covalent immobilization of cellic CTec2 cellulase: enabling enzyme reusability in cellulosic biomass conversion

A modified chemical co-precipitation method was employed to synthesize silicacoated-aminefunctionalized iron oxide nanoparticle (IONP@SiO2-NH2) which has been utilized as an anchoring surface for enzyme immobilization. Cellulase Cellic CTec2 cocktail was immobilized covalently onto IONP@SiO2-NH2 using glutaraldehyde as a linker. The morphological, structural, and compositional studies of nanoparticles were characterized by field emission scanning electron microscopy with energy dispersive X-ray (FESEM)-EDX, Fourier transform infrared (FTIR), X-ray diffraction (XRD), zeta potential, and Ultraviolet/visible (UV-Vis) spectroscopy. The FTIR, FESEM, and XRD spectra confirmed the successful immobilization of cellulase onto IONP@SiO2-NH2. The free enzymewith cellulase activity of 127 FPU/mL was optimized for the immobilization process which showed the best binding efficiency at 2% glutaraldehyde, protein loading 100 mg/g with carboxymethyl cellulase activity of 290 IU/g, and total immobilization yield of 70.8%. The immobilized cellulase exhibited enhanced stability for temperature and pH over a broader rangethan the free enzyme. The immobilized enzyme-mediated hydrolysis of 1% carboxymethyl cellulose (CMC) released 0.54 g glucose/g substrate at 24 h, showing potential for cellulosic biomass conversion. The immobilized cellulase which was investigated for reusability assay retained∼80% activity even after repeated 6 cycles of CMC hydrolysis. The results showed good reusability after magnetic separation, which is the main advantage of using this nanobiocatalyst system.

N-Hydroxysuccinamide functionalized iron oxide nanoparticles conjugated with 5-flurouracil for hyperthermic therapy of malignant liver cancer cells by DNA repair disruption

Magnetized iron oxide nanoparticles are ideal materials for biological and biomedical applications due to their biocompatibility, super paramagnetic behavior, surface capability, and chemical stability. This research article is narrating the overview of methodologies of preparation, functionalization, characterization and applications of Fe3O4 nanoparticles. Super paramagnetic nanoparticles are studied for their hyperthermia properties. The proposed mechanism behind the hyperthermia was damaging the proteins responsible for DNA repair thereby, directly accelerating the DNA damages on cancer cells by increasing the temperature in the vicinity of the cancer cells. In this study, super paramagnetic iron oxide (Fe3O4) nanoparticles (SPIONs) and anti-cancer drug, 5-fluorouracil, functionalized with N-Hydroxysuccinimide organic molecules. A specific absorption rate at 351 nm can be achieved using UV analysis. The magnetic Fe3O4 nanoparticles had a cubic crystalline structure. FE-SEM(field emission scanning Electron microscopy) with EDAX(energy dispersive X-ray analysis) analysis shows that the size of the SPION was about 30–100 nm range and the percentage of chemical compositions was higher in the order of Fe, O, C. for particle size analysis, the SPION were positively charged derived at +9.9 mV and its conductivity is measured at 0.826 mS/cm. In-vitro anti-cancerous activity analysis in Hep-G2 cells (liver cancer cells) shows that the 5-fluorouracil functionalized SPIONs have higher inhibition rate than the bare Fe3O4 nanoparticles. The Fe3O4 nanoparticles were studied for their hyperthermic abilities at two different frequencies such as 3.05 × 106 kAm−1s−1 and 4.58 × 106 kAm−1s−1.The bare Fe3O4 at low magnetic field, 10 mg was required to raise the temperature above 42°- 45 °C and at high magnetic field, 6 mg was enough to raise the same temperature. The 5-fluorouracil functionalized Fe3O4 shows that at low magnetic field, 6 mg is required to raise the hyperthermia temperature and at high magnetic field, 3 mg is required to raise the temperature above 42°- 45 °C. the rate of heating and the temperature achieved with time can be tuned with concentrations as well as magnetic component present in the Fe3O4 nanoparticles. Beyond this concentration, the rate of cell death was observed to increase. The saturation and low residual magnetization were revealed by the magnetization analysis, making them well suited for clinical applications

Bi-enzymatic nanobiocatalyst based on immobilization of xylanase and pectinase onto functionalized magnetic nanoparticles for efficient fruit juice clarification

An efficient enhancement in fruit juice quality achieves by simultaneously hydrolyzing polysaccharides in one pot reaction. Herein, an efficient approach is reported to fabricate a novel nanobiocatalyt for clarification of fruit juices based on covalent co-immobilization of pectinase and xylanase onto functionalized iron oxide nanoparticles. The highest activity recovery of the co-immobilized enzymes was achieved at 0.5 mg/mL of total protein, 8:1 w/w pectinase to xylanase ratio, and 6 h incubation time. Thermal and pH stabilities studies showed improved performance of co-immobilized enzymes compared to free counterparts. The co-immobilized pectinase and xylanase respectively retained more than 74% and 48% of residual activity after six consecutive cycles. Moreover, 53% turbidity reduction in pineapple juice was achieved after 120 min treatment with developed nanobiocatalyst. Besides, more than 64% of the initial activity of enzymes was retained after nine reuses, suggesting that this bi-enzyme nanobiocatalyst has potential application in industrial juice processing.

Abstract 3590: Targeted detection of ovarian cancer using functionalized iron oxide nanoparticles

Abstract SuperParaMagnetic Relaxometry (SPMR) is a highly sensitive detection technology that can differentiate the magnetic signature of nanoparticles (NP) bound to tumor cells from unbound nanoparticles. Nanoparticles that reach and bind to the target cells are measurable by superconducting quantum interference device (SQUID) magnetometers (MRX instrument developed in house), while unbound nanoparticles such as those freely circulating in the bloodstream are not detected and bone and normal tissue do not produce any magnetic signal. We have developed a protocol to produce high precision 25nm+1nm (<7% dispersion) Fe3O4 nanoparticle core. These core nanoparticles are coated by a polymer shell functionalized with carboxylate groups. Antibody are then conjugated on the surface providing molecular targeting capabilities and PEG is also attached to the surface to reduce opsonization. In previous studies, we have demonstrated that when conjugated with anti-HER2 antibody such as Herceptin, these nanoparticles exhibited great specificity and selectivity towards HER2+ tumor cells in vitro and in vivo. In current studies, we expanded our nanoparticles applications to other type of cancers, such as ovarian cancer. The CA125 is a tissue-specific antigen expressed in ovarian cancer. It is associated with greater than 80% of epithelial ovarian neoplasms. OC125, a murine monoclonal antibody, reacts with glycosylation-dependent antigens present exclusively in the cleaved portion of the molecule. OC125 antibody is conjugated to our nanoparticles using the same strategy developed for Herceptin nanoparticles. Each nanoparticle contains one to three OC125 antibody molecules covalently attached to the surface based on ELISA analysis. Our results have shown that OC125-NP can distinguish CA125+ and CA125- cell lines, OVCAR3 and HeyA8 respectively. Positive signal can be competed out by pre-incubation with free OC125 antibody and negative cell line produce undetectable SPMR signal, demonstrating good sensitivity, specificity and selectivity. Antigen glypican-1 (GPC1) is a proteoglycan located on cell surface composed of a membrane-associated protein core anchored to the cytoplasmic membrane. GPC1 may play a functional role in the control of cell division and growth regulation. The expression of GPC1 has been found to be elevated in many cancer cells, including ovarian. Applying the same conjugation strategy developed for Herceptin NP, humanized anti-GPC1 antibody is conjugated to the nanoparticles with minor modification. GPC1-NP generate appreciable signal using SKOV3 cell line (GPC1+ ovarian cell lines) and the signal can be competed out by the presence of excess free GPC1 antibody. Together, these results suggest that in additional to breast cancer application, our antibody functionalized nanoparticle system can be developed for other targeted cancer detection, such as ovarian cancer. Citation Format: Marie Zhang, Eric Smith-Nguyen. Targeted detection of ovarian cancer using functionalized iron oxide nanoparticles. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3590.

Abstract 3586: In vivo targeted detection and imaging of ovarian cancer by SPMR and MRI using anti-folate receptor functionalized iron oxide nanoparticles

Abstract Ovarian cancer is the second most common and most deadly gynecological cancer in women. Early and accurate detection is crucial in improving survival rate and quality of life of patients. Folate receptor alpha (FRα) is a folate transporter that has been reported to be overexpressed in approximately 90% of ovarian cancer, which makes it a suitable molecular target to use in developing tumor imaging methods. Iron oxide nanoparticles (NPs) have been used in a variety of cancer detection/imaging applications. Here we show that anti-FRα targeted superparamagnetic iron oxide nanoparticles (SPION) can be used for in vivo detection by two different imaging methods. Superparamagnetic Relaxometry (SPMR) is a highly sensitive in vivo detection technology that is able to differentiate the magnetic signature of nanoparticles bound to tumor cells from unbound nanoparticles. Same targeted SPIONs accumulated in tumor are able to provide molecular magnetic resonance imaging (MRI) contrast as well. Our results have shown that the anti-FRα NPs can distinguish high and low FRα expression cell lines, such as KB and A549, respectively in an in vitro cell based assay by SPMR, demonstrating good sensitivity, specificity and selectivity. In vivo study using xenograph model with KB and A549 cells implanted subcutaneously on the flank region of female athymic nude mice demonstrated higher level tumor accumulation of anti-FRα NPs in KB tumor compared to A549 tumor, measurable by ex vivo tumor detection using SPMR. Using a PEG NPs (without the target ligand) as control for the mice study have shown that minimum nanoparticle tumor accumulated were observed, demonstrating the specificity of the nanoparticles in vivo. Organ distribution study indicated that anti-FRα NPs mostly accumulated in liver and spleen as these nanoparticles were cleared through these two organs. Other organs such as brain, heart, lung, kidney didn’t show appreciable accumulation. The repeat of same type of xenograph mice model used in the SPMR study is currently under the way using MRI as an alternative in vivo detection method with images taken pre- and post- dosing of the nanoparticles. Based on the specificity and sufficient accumulation of nanoparticles demonstrated in the SPMR study, it is expected that MRI will show similar performance with additional anatomical information.Our anti-FRα NPs provided targeted and specific delivery to cancerous tissue and generated measurable signal by SPMR. Furthermore, demonstration of these anti-FRα NPs generating tumor specific contrast in MRI is currently under the way. These studies lay the groundwork for use of bio-safe magnetic particles as a detection and contrast agent for early ovarian cancer detection with improved accuracy to minimize the needs of invasive biopsies/surgery as well as potential utility for monitoring therapy response or recurrence. Citation Format: Marie Zhang, Kathirvel Kandasamy, Yamitha Perera, Dan Inglese, Eric Smith-Nguyen. In vivo targeted detection and imaging of ovarian cancer by SPMR and MRI using anti-folate receptor functionalized iron oxide nanoparticles. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3586.

Effect of the Size and Shape of Dendronized Iron Oxide Nanoparticles Bearing a Targeting Ligand on MRI, Magnetic Hyperthermia, and Photothermia Properties-From Suspension to In Vitro Studies.

Functionalized iron oxide nanoparticles (IONPs) are increasingly being designed as a theranostic nanoplatform combining specific targeting, diagnosis by magnetic resonance imaging (MRI), and multimodal therapy by hyperthermia. The effect of the size and the shape of IONPs is of tremendous importance to develop theranostic nanoobjects displaying efficient MRI contrast agents and hyperthermia agent via the combination of magnetic hyperthermia (MH) and/or photothermia (PTT). Another key parameter is that the amount of accumulation of IONPs in cancerous cells is sufficiently high, which often requires the grafting of specific targeting ligands (TLs). Herein, IONPs with nanoplate and nanocube shapes, which are promising to combine magnetic hyperthermia (MH) and photothermia (PTT), were synthesized by the thermal decomposition method and coated with a designed dendron molecule to ensure their biocompatibility and colloidal stability in suspension. Then, the efficiency of these dendronized IONPs as contrast agents (CAs) for MRI and their ability to heat via MH or PTT were investigated. The 22 nm nanospheres and the 19 nm nanocubes presented the most promising theranostic properties (respectively, r2 = 416 s-1·mM-1, SARMH = 580 W·g-1, SARPTT = 800 W·g-1; and r2 = 407 s-1·mM-1, SARMH = 899 W·g-1, SARPTT = 300 W·g-1). MH experiments have proven that the heating power mainly originates from Brownian relaxation and that SAR values can remain high if IONPs are prealigned with a magnet. This raises hope that heating will maintain efficient even in a confined environment, such as in cells or in tumors. Preliminary in vitro MH and PTT experiments have shown the promising effect of the cubic shaped IONPs, even though the experiments should be repeated with an improved set-up. Finally, the grafting of a specific peptide (P22) as a TL for head and neck cancers (HNCs) has shown the positive impact of the TL to enhance IONP accumulation in cells.

Study on Doxorubicin Loading on Differently Functionalized Iron Oxide Nanoparticles: Implications for Controlled Drug-Delivery Application

Nanoplatforms applied for the loading of anticancer drugs is a cutting-edge approach for drug delivery to tumors and reduction of toxic effects on healthy cells. In this study, we describe the synthesis and compare the sorption properties of four types of potential doxorubicin-carriers, in which iron oxide nanoparticles (IONs) are functionalized with cationic (polyethylenimine, PEI), anionic (polystyrenesulfonate, PSS), and nonionic (dextran) polymers, as well as with porous carbon. The IONs are thoroughly characterized by X-ray diffraction, IR spectroscopy, high resolution TEM (HRTEM), SEM, magnetic susceptibility, and the zeta-potential measurements in the pH range of 3-10. The degree of doxorubicin loading at pH 7.4, as well as the degree of desorption at pH 5.0, distinctive to cancerous tumor environment, are measured. Particles modified with PEI were shown to exhibit the highest loading capacity, while the greatest release at pH 5 (up to 30%) occurs from the surface of magnetite decorated with PSS. Such a slow release of the drug would imply a prolonged tumor-inhibiting action on the affected tissue or organ. Assessment of the toxicity (using Neuro2A cell line) for PEI- and PSS-modified IONs showed no negative effect. In conclusion, the preliminary evaluation of the effects of IONs coated with PSS and PEI on the rate of blood clotting was carried out. The results obtained can be taken into account when developing new drug delivery platforms.

Synthesis and Surface Modification of Iron Oxide Nanoparticles for the Extraction of Cadmium Ions in Food and Water Samples: A Chemometric Study

In this project, a prompt, efficient, and effective method for Cd2+ ions extraction from different food and water samples using magnetic dispersion-based solid phase extraction by functionalized iron oxide nanoparticles was proposed. Iron oxide nanoparticles were synthesized through the co-precipitation method followed by functionalization with tetraethyl orthosilicate (TEOS) and 3-aminopropyl silane (APTES) to obtain Fe3O4@SiO2@APTES. This composite was characterized through different techniques, including vibrating sample magnetometer, dynamic light scattering, zeta potential, FTIR, SEM, XRD, and BET. Variables studied were pH, temperature, sorbent amount, sonication time, and sample and eluent volume affecting the sorption efficacy of freshly synthesized sorbent. Plackett–Burman design was utilized for the identification of significant factors for microextraction of target analyte, while the central composite design was utilized for the optimization of significant factors. Detection and quantification limits obtained were 0.17 and 0.58 μgL−1, respectively, with an enhancement factor of 83.5. Under optimum conditions, Fe3O4@SiO2@APTES showed good stability even after >80 adsorption/desorption cycles run while maintaining over 96% analyte recoveries. The developed method was validated by assessing certified reference materials and standard addition methodology for Cd2+ detection in real samples. To confirm the precision, repeatability (RSDr) and reproducibility (RSDR) were calculated and found as <3.0 (n = 7) and <7.5 (n = 15), respectively. Furthermore, in accordance with the ISO/IEC 17025 recommendations, the validation was also confirmed through a “bottom-up” approach while considering all possible uncertainties in data.

Nano-depletion of morbid spermatozoa up-regulate Ca2+ channel, depolarization of membrane potential and fertility in buffalo

Despite recent advances in technique of spermatozoa cryopreservation, there are still ejaculates present that fail to meet strict quality standard; mainly due to detrimental effect of imbalance of free radicals. The omnipresence of dead/defective spermatozoa in ejaculates of eutherian species is a major source of excessive free radicals. Though sperm-selection techniques, as well as addition of antioxidants addressed the problem to a certain extent, the major source of free radicals in the semen remained, causing much damage. This study attempts to remove dead/damaged spermatozoa using negative fertility-marker. The effect is unraveled by Hypo-osmotic (HOS), and fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) assay, further confirmed by Ca2+-regulating mechanisms and depolarization of sperm membrane potential, reduction in concentration of free radicals and finally by in vitro fertility assay. The study involved functionalization of iron oxide nanoparticles (IONPs) with silane followed by bio-conjugation with anti-ubiquitin antibodies. The nano-purification of semen using anti-ubiquitin conjugated iron oxide nanoparticles (IONPs) (antibody concentrations 0.5, 1.0 and 2.0 μg/ml) was attempted. The efficiency of nano-purification was 18.1%–43.8% in the study. The results revealed greater (P ≤ 0.05) spermatozoa population with intact plasma membrane, acrosome integrity, high mitochondrial membrane potential and pattern-F (least intracellular Ca2+), evidence of low lipid peroxidation and higher total antioxidant capacity in nano-purified groups. More number of spermatozoa were bound to zona pellucida of matured oocytes from nano-depleted than non-depleted group. The findings demonstrate antibody concentration of 1.0 μg/ml bio-conjugated with IONPs as most efficient in enriching the ejaculate with functional spermatozoa with the highest percentage of zona binding.

Influence of Polymer Shell Molecular Weight on Functionalized Iron Oxide Nanoparticles Morphology and In Vivo Biodistribution.

Iron oxide nanoparticles (IONPs) have been extensively used in different biomedical applications due to their biocompatibility and magnetic properties. However, different functionalization approaches have been developed to improve their time-life in the systemic circulation. Here, we have synthesized IONPs using a modified Massart method and functionalized them in situ with polyethylene glycol with different molecular weights (20 K and 35 K). The resulting nanoparticles were characterized in terms of morphology, structure, and composition using transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In vivo biodistribution was evaluated in Balb/c mice, the presence of IONP being evidenced through histopathological investigations. IONP morphological characterization showed a change in shape (from spherical to rhombic) and size with molecular weight, while structural characterization proved the obtaining of highly crystalline samples of spinel structured cubic face-centered magnetite. In vivo biodistribution in a mice model proved the biocompatibility of all of the IONP samples. All NPs were cleared through the liver, spleen, and lungs, while bare IONPs were also evidenced in kidneys.

Progress toward Room-Temperature Synthesis and Functionalization of Iron-Oxide Nanoparticles.

Novel magnetic nanohybrids composed of nanomaghemite covered by organic molecules were successfully synthesized at room temperature with different functionalization agents (sodium polystyrene sulfonate, oxalic acid, and cetyltrimethylammonium bromide) in low and high concentrations. Structural, vibrational, morphological, electron energy-loss spectroscopy, magnetic, and Mössbauer characterizations unraveled the presence of mainly cubic inverse spinel maghemite (γ-Fe2O3), whilst X-ray diffraction and 57Fe Mössbauer spectroscopy showed that most samples contain a minor amount of goethite phase (α-FeOOH). Raman analysis at different laser power revealed a threshold value of 0.83 mW for all samples, for which the γ-Fe2O3 to α-Fe2O3 phase transition was observed. Imaging microscopy revealed controlled-size morphologies of nanoparticles, with sizes in the range from 8 to 12 nm. Organic functionalization of the magnetic nanoparticles was demonstrated by vibrational and thermogravimetric measurements. For some samples, Raman, magnetic, and Mössbauer measurements suggested an even more complex core-shell-like configuration, with a thin shell containing magnetite (Fe3O4) covering the γ-Fe2O3 surface, thus causing an increase in the saturation magnetization of approximately 11% against nanomaghemite. Field cooling hysteresis curves at 5 K did not evidence an exchange bias effect, confirming that the goethite phase is not directly interacting magnetically with the functionalized maghemite nanoparticles. These magnetic nanohybrids may be suitable for applications in effluent remediation and biomedicine.

PH-responsive glycine functionalized magnetic iron oxide nanoparticles for SARS-CoV-2 RNA extraction from clinical sample.

The recent outbreak of the novel corona virus disease 2019 (COVID-19) has been made a serious global impact due to its high infectivity and severe symptoms. The Severe Acute Respiratory Syndrome (SARS-CoV-2) RNA extraction is considered as one of the most important steps in COVID-19 detection. Several commercially available kits and techniques are currently being used for specific extraction of SARS-CoV-2 RNA. However, such methods are time consuming and expensive due to the requirement of trained labors, and several chemical reagents. To overcome the mentioned limitations, magnetic RNA adsorption methodology of glycine functionalized iron oxide nanoparticles (GNPs) was established. It showed an efficient potential in SARS-CoV-2 RNA extraction due to pH responsive nature of GNPs. The highly magnetic pH responsive GNPs were synthesized by one-pot co-precipitation method. Random morphology and average 20 nm size of GNPs were denoted by Transmission Electron Microscopy (TEM). X-ray diffractometer (XRD) showed the crystalline magnetite nature. Fourier transform infrared spectroscopy (FT-IR) and UV–visible spectrometry confirmed the presence of glycine on the surface of magnetic nanoparticles. Furthermore, the magnetic nature and thermal properties of GNPs were examined by vibrating sample magnetometer (VSM) and thermo-gravimetric analysis (TGA), respectively. In this study, glycine performed the role of RNA adsorbent. The adsorption of RNA onto the surface of GNPs was achieved in acidic medium (pH 6). In contrary, the elution of RNA from the surface of GNPs was achieved in basic medium (pH 8). The purity of obtained RNA was analyzed by UV–visible spectrometry. Further, the obtained RNA was examined for the presence of SARS-CoV-2 specific Envelope (E), RNA dependent RNA polymerase (RDRP) and Nucleocapsid (N) genes using an RT-PCR analysis. It showed the sudden rise in amount of these genes after 25 cycles of RT-PCR and hence indicated the efficient RNA extraction by GNPs. Agarose gel electrophoresis was used for validation of the quantity and quality of RNA extracted from SARS-CoV-2 patient’s sample. The reusability studies of GNPs were performed by monitoring the repeated use of GNPs for SARS-CoV-2 RNA extraction. This method possesses potential role in the field of disease diagnosis. The extraction results of RNA from SARS-CoV-2 patient’s sample indicated that the GNPs have an outstanding property over the current existing extraction protocols. It leads to the new advancements in extraction and detection of RNA.Graphical Graphical abstract of the pH responsive SARS-CoV-2 RNA extraction by using glycine functionalized magnetic iron oxide nanoparticles (GNPs) which were prepared by modified cost effective one pot chemical synthesis method. Prepared GNPs were characterized by XRD, FT-IR and UV-Visible spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Glycine present on the surface of nanoparticles (NPs) played an important role in pH responsive RNA extraction procedure. When nanoparticles added in acidic (pH < 7) medium, glycine gained positive surface charge hence overall surface charge of NPs became positive. Thereby SARS-CoV-2 RNA adsorption/binding occurred on the surface of GNP. Later, the RNA-GNP complex was separated by an external magnet. Separated complex was added in basic (pH > 7) medium to elute RNA from GNP. This phenomenon occurred due to surface negative charge of glycine that caused charge repulsion with RNA. Eluted RNA was examined qualitatively and quantitatively by RT-PCR, nanodrop technique and agarose gel electrophoresis. Results were compared with kit based extracted RNA. Supplementary InformationThe online version contains supplementary material available at 10.1007/s10853-022-07464-6.

Langmuir–Blodgett based ordered deposition of functionalized iron oxide nanoparticles for ultrasensitive detection of Escherichia coli O157: H7

We report the synthesis and deposition of highly ordered poly(lactic-co-glycolic acid) coated iron oxide nanoparticles (Plg-IONPs) using the surface pressure-controlled Langmuir-Blodgett (LB) method. The deposition of different monolayers (2, 4, and 6 layers) has been attained by transferring the spread solution of Plg-IONPs at an optimized pressure (14 mN m-1) and temperature (25 °C). Surface morphological studies carried out using scanning electron microscopy clearly show the uniform deposition of Plg-IONPs@LB thin film on indium tin oxide (ITO) coated glass substrate. The Plg-IONPs@LB/ITO electrodes have been conjugated with monoclonal antibodies specific to Escherichia coli O157: H7 (E. coli). The fabricated biosensor has been utilized to detect E. coli in the concentration range 5.0 CFU mL−1to 106CFUmL−1 with a limit of detection of 3.0 CFU mL−1. Further, the biosensor has shown specificity for detecting E. coliand has been able to discriminate other potential bacterial pathogens and non-pathogenicE. colistrain (DH5α). As a proof of concept, the biosensor has been able to quantify E. coli O157: H7 in spiked food and water samples with high accuracy and reproducibility.

Co-exposure of iron oxide nanoparticles and glyphosate-based herbicide promote liver toxicity in guppy (Poecilia reticulata): A histochemical and ultrastructural approach.

Citrate functionalized iron oxide nanoparticles (IONPs) are employed for various purposes-including environmental remediation but the interaction of IONPs with aquatic contaminants is poorly understood. Among those, glyphosate-based herbicides are toxic and affect target organs such as the liver. Evaluations of livers of female Poecilia reticulata by exposures to IONPs at a concentration of 0.3mg/L were performed with association to: (1) 0.65 mg of glyphosate per litter and (2) 1.3mg of glyphosate per litter of Roundup Original, and (3) glyphosate P.A at 0.65 mg/L. These associations were carried out progressively, after 7, 14, and 21 days. We detected circulatory disturbances, inflammatory responses, activation of the immune system, regressive changes, and progressive responses with changes in the connective tissue and decreased glycogen reserve from days 14 to 21. Ultrastructural changes in the Disse space and microvilli of hepatocytes indicated decreased contact surface area. In general, the damage was time and concentration dependent, increasing from 7 to 14 days and tending to stabilize from 14 to 21 days. Therefore, herbicide-associated IONPs functioned as xenobiotics inducing intense cellular detoxification processes and activation of hepatic immune responses.

Functionalized iron oxide nanoparticles: synthesis through ultrasonic-assisted co-precipitation and performance as hyperthermic agents for biomedical applications

Dual-functional iron oxide nanoparticles (IONPs), displaying self-heating and antibacterial effects are highly desired for biomedical application. This study involved the synthesis of functionalized IONPs coated with 3-aminopropyltriethoxysilane and polyethylene glycol via ultrasonic-assisted co-precipitation technique. The synthesized IONPs were then characterized by using Fourier-transform infrared spectroscopy, X-ray diffraction, dynamic light scattering, scanning electron microscopy, zeta potential, vibrating sample magnetometer and thermogravimetric analysis techniques. In addition, the effect of the synthesized IONPs on bacterial growth (S. aureus and E. coli) was studied. The influence of magnetic field power, as well as the viscous carriers on the heating efficiency of the synthesized IONPs was investigated. The specific absorption rate values increased as the power increased and decreased with the increase in the carrier viscosity. These characteristics render the synthesized iron oxide nanoparticles synthesized in the present study suitable for biomedical application as hyperthermic agents.

Design and Synthesis of Multipotent Antioxidants for Functionalization of Iron Oxide Nanoparticles

Multipotent antioxidants (MPAO) were synthesized and characterized by FTIR, NMR. The functionalized nanoparticles (IONP@AO) were characterized by FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX. IONP@AO1 and IONP@AO2 have average particles size of 10 nm and 11 nm, respectively. The functionalized IONP@AO has a superparamagnetic nature, with saturation magnetization of 45 emu·g−1. Structure-based virtual screening of the designed MPAO was performed by PASS analysis and ADMET studies to discover and predict the molecule’s potential bioactivities and safety profile before the synthesis procedure. The half-maximal inhibitory concentration (IC50) of DPPH analysis results showed a four-fold decrease in radical scavenging by IONP@AO compared to IONP. In addition to antioxidant activity, IONP@AO showed suitable antimicrobial activities when tested on various bacterial and fungal strains. The advantage of the developed nanoantioxidants is that they have a strong affinity towards biomolecules such as enzymes, proteins, amino acids, and DNA. Thus, synthesized nanoantioxidants can be used to develop biomedicines that can act as antioxidant, antimicrobial, and anticancer agents.

Epoxy functionalized iron oxide magnetic nanoparticles for catalase enzyme covalent immobilization

An aqueous solution of magnetite (Fe3O4) nanoparticles was synthesized using the method of co-precipitation. The nanoparticles were activated with epichlorohydrin for covalently immobilizing the catalase enzyme. The immobilization conditions were optimized as 0.07 mg/ml catalase for 1 h contact time. The properties of free and immobilized catalase were also investigated. The immobilized enzyme showed enhanced activity at alkaline pH and retained about 90% of its relative activity between pH (6–8) and resisted the high temperature and retained 90% of its relative activity at 50 °C. Kinetic parameters of free and immobilized catalase were investigated. While the Vmax value of the immobilized enzyme was reduced 2.4 fold compared to the free enzyme, the KM value of the immobilized catalase was higher by 2.2 fold than the free enzyme. The formulated matrix enhanced the velocity of the immobilized catalase more than the free one and was able to be used for about 18 cycles with retention of 80% of its activity. The immobilized catalase on epoxy functionalized iron oxide nanoparticles is promising as a nano-bio-catalyst carrying out in many industries and different fields.

A Magnetic Sensor Based on Poly(γ-Glutamic Acid)-Functionalized Iron Oxide Nanoparticles for Cr3+ Detection

Background: The highly sensitive and selective detection of Cr3+ is critical. Objective: We report the development of poly(γ-glutamic acid) (γ-PGA)-functionalized iron oxide nanoparticles (γ-PGA-Fe3O4 NPs) as a magnetic nanosensor for magnetic resonance (MR) detection of trivalent chromium (Cr3+) in aqueous solution. Methods: The γ-PGA-Fe3O4 NPs with a mean particle size of 7.3 nm, good colloidal stability and ultrahigh r2 relaxivity (326.8 mM−1s−1) were synthesized via a facile mild reduction approach in the presence of γ-PGA, and used for MR detection of Cr3+. Results: Upon exposure to Cr3+, the γ-PGA-Fe3O4 NPs aggregated into nanoclusters as verified by dynamic light scattering due to the coordination of Cr3+ with γ-PGA side chain carboxyl groups, resulting in the decrease in their transverse relaxation time. This MR signal change enables detection of Cr3+ in a concentration range of 0.4-1 nM. We also show that the γ-PGA-Fe3O4 NPs have an excellent selectivity toward Cr3+ and a high recovery percentage of 83.8% or above. Conclusion: This study thus demonstrates that the developed γ-PGA-Fe3O4 NPs may be used as a nanoprobe for MR sensing of Cr3+ in water environment.