Incorporation Of Magnetic Nanoparticles Research Articles

Magnetically controlled transdermal delivery of gemcitabine via xanthan gum-coated magnetic nanoparticles embedded in gellan gum cryogel

Chemotherapy is a commonly used treatment for breast cancer, but it often causes significant side effects due to the high drug dosage required for injection or infusion administration. Transdermal drug delivery offers a non-invasive and controlled release approach. In this work, a novel approach was developed for using gellan gum as a drug matrix and Gemcitabine loaded xanthan gum coated Fe3O4 magnetic nanoparticles (Gem: Xan (1%v/v)Fe3O4) as a drug carrier complex. The magnetization values were found to be 84.69 emu/g, 16.63 emu/g, and 9.91 emu/g for Fe3O4, Xan (1%v/v)Fe3O4, and Gem: Xan (1%v/v)Fe3O4, respectively. Notably, this work showcases the synthesis of Gemcitabine loaded xanthan gum coated magnetic nanoparticles as a new drug carrier complex, explores the drug release kinetics, and demonstrates the biocompatibility and non-toxicity of gellan gum on human skin, offering promising implications for transdermal drug delivery. The Gemcitabine release was 54 % without magnetic nanoparticles, and it increased to 82 % with the incorporation of magnetic nanoparticles. The Gemcitabine release – permeation of Gem: Xan (1%v/v)Fe3O4 was higher than that of the pristine Gemcitabine permeation by 72 %. The experimental results revealed that the magnetic field played a crucial role in controlling the drug release rate, amount, and duration during the release and release-permeation study.

Enhancing thermoelectric performance with perpendicular anisotropic magnetic domain arrays

In recent years, the incorporation of magnetic nanoparticles into thermoelectric materials has been introduced to enhance their performance. However, understanding the impact of dispersed magnetic substances in the matrix on thermoelectric properties, considering different domain directions, is crucial for performance improvement. In this study, we have designed and fabricated high-quality epitaxial single crystal thin films consisting of FePt arrays with varying magnetic domain directions embedded in an Sb2Te3 matrix. Our findings reveal that the electrical transport behavior of the films responds differently to magnetic materials with distinct domain directions, especially in the case of discontinuous arrays. The FePt array oriented perpendicular to the carrier flow direction effectively regulates the direction of carrier movement and local low-energy carriers, functioning as an "energy supplier" to enhance material performance. Simultaneously, the quantum dots formed between the Sb2Te3 and the metal film play the role of carrier channels, further regulating the carrier concentration. Therefore, the perpendicular magnetic anisotropy array synergistically modulates the electrical transport behavior through carriers, resulting in a significant improvement in the thermoelectric power factor. By increasing the S value at the measurement temperature, we achieved a maximum power factor (PFmax) of 3.35 mWm-1K-2 and an average power factor (PFave) of 3.14 mWm-1K-2.

Development of magnetic nanocomposite hydrogels for removal of pesticide from water

Using magnetic and biodegradable polymers for removal of soluble pesticides can reduce environmental and human health damage caused by their presence in rivers, streams, and lakes. In this study, we develop and characterize the crystallinity and thermal properties of novel magnetic hydrogels based on polysaccharides, zeolites, and magnetite (Fe3O4) magnetic nanoparticles (MNs) functionalized with 3-aminopropyltriethoxysilane (Fe3O4@NH2), supported in poly(methacrylic acid)-co-polyacrylamide networks. The potential of the hydrogel for herbicide removal, specifically paraquat, is also investigated. The Fourier-transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetric, kinetic, and swelling degree analysis results demonstrate that MNs do not affect the physicochemical properties and pesticide sorption. However, minor changes, such as the peak at 2θ = 35.57º representing the (311) plane of Fe3O4, confirmed the incorporation of MNs into the polymer matrix. The increase in pH caused an increase in the swelling degree from 1.2 to 10.0 w.w−1, indicating an increase both the pore size, and possibly, in the removal properties. The adsorption results of paraquat through ultraviolet–visible spectroscopy measurements show a small difference in absorptive capacity (qeq) between pure hydrogel (12.95 mg.g−1) and hydrogel with 2.0 % functionalized Fe3O4 NPs (12.99 mg.g−1). Overall, incorporating Fe3O4 NPs in the hydrogel matrix yields materials with promising characteristics and while offering easier, safer removal from the environment.

MXene confined microcapsules for uremic toxins elimination

AbstractAdsorbents with high adsorption efficiency and excellent biosafety for biomedical applications are highly required. MXene is a promising candidate owning these advantages, yet pristine MXene faces dilemmas including insufficient utility of surface site as well as limited processibility. Here, we develop MXene‐encapsulated porous microcapsules via microfluidics. The microcapsules have a biomass hydrogel shell that provides robust support for MXene in the core, by which the microcapsules are endowed with high MXene dosage and remarkable biosafety. Additionally, the MXene nanoflakes assemble into a three‐dimensional network via metal ion‐induced gelation, thereby avoiding restacking and significantly improving surface utilization. Moreover, a freeze‐pretreatment of the microcapsules during preparation results in the formation of a macroporous structure in the shell, which can facilitate the diffusion of the target molecules. These features, combined with additional magneto‐responsiveness rendered by the incorporation of magnetic nanoparticles, contribute to prominent performances of the microcapsules in cleaning uremia toxins including creatinine, urea, and uric acid. Thus, it is anticipated that the MXene‐encapsulated microcapsules will be promising adsorbents in dialysis‐related applications, and the combination of microfluidic encapsulation with metal ion gelation will provide a novel approach for construction of hybrid MXene materials with desired functions.

Magnetically controlled insertion of magnetic nanoparticles into membrane model

Polysaccharide–coated magnetic nanoparticles (MNPs) have been reported to show potential applications in many biomedical fields. In this report, we have studied the interactions between magnetite (Fe3O4) MNPs functionalized with polysaccharides (diethylamino–ethyl dextran, DEAE–D or chitosan, CHI) with different membranes models by Langmuir isotherms, incorporation experiments, and brewster angle microscopy (BAM). In this report, zwitterionic 1,2–distearoyl–sn–glycerol–3–phosphoethanolamine (DSPE) and anionic 1,2–distearoyl–sn–glycerol–3–phosphate (DSPA) phospholipid, were used to form membrane models. Incorporation experiments (π–t) as well as the compression isotherms demonstrate positive interactions between MNPs and DSPE or DSPA monolayers. The study assessed the impact of varying initial surface pressure on a preformed phospholipid monolayer to determine the maximum insertion pressure (MIP) and synergy. Our findings indicate that the primary driving force of the coated MNPs incorporation into the monolayer predominantly stems from electrostatic interaction. The drop in the subphase pH from 6.0 to 4.0 led to an enhancement of the MIP value for DSPA phospholipid monolayer. On the other hand, for DSPE, the drop in the pH does not affect the MIP values. Besides, the presence of a magnetic field induces an enhancement of the insertion process of the MNPs into DSPA preformed monolayer, demonstrating that a previous interaction between MNPs and phospholipid preformed monolayer needs to take place to enhance the incorporation process. This work opens novel perspectives for the research of the influence of magnetic fields on the incorporation of MNPs into model membranes.

Optical, microstructural, and magnetic hyperthermia properties of green-synthesized Fe3O4/carbon dots nanocomposites utilizing Moringa oleifera extract and watermelon rinds

Cancer therapy with targeted-localized heating is one of the breakthroughs in the biomedical field. The incorporation of magnetic nanoparticles and fluorescent nanoparticles was one of the crucial issues for magnetic hyperthermia applications. This research investigates the magnetic hyperthermia properties of green-synthesized Fe3O4/CDs. Fe3O4 nanoparticles were synthesized using the coprecipitation method with Moringa oleifera leaf extract as a reducing agent and stabilizer. In contrast, CDs were synthesized using a hydrothermal method with watermelon rind waste as a carbon source. X-ray diffraction analysis confirmed the presence of cubic inverse spinel and a reduction in crystallite size with increasing CDs concentration. Transmission electron microscopy revealed particle size distributions of 9.7 nm for Fe3O4 and 7.5 nm for Fe3O4/CDs. Scanning electron microscopy showed that CDs were distributed on the surface of Fe3O4. The detection of characteristic FeO, CC, CO, and CO-C bonds indicated the presence of CDs on the surface of Fe3O4. Ultraviolet-visible spectroscopy spectra absorption peaks at 282 nm for CDs and 193 nm for Fe3O4. Photoluminescence spectra indicated shifts from 509 to 505 nm in excitation wavelength for both CDs and Fe3O4/CDs, situated within the green region of visible light. The vibrating sample magnetometer revealed that the nanocomposites displayed characteristics of soft ferromagnetic materials. Furthermore, the specific absorption rate (SAR) value of Fe3O4/CDs was found to be dependent on magnetization. The SAR value of Fe3O4/CDs decreased as the concentration of CDs increased, and the frequency and strength of the AMF increased. Therefore, these results can promote Fe3O4/CDs nanocomposites as a promising candidate for magnetic hyperthermia applications.

Smart metal-organic framework (MOF) composites and their applications in environmental remediation

The applications of stimuli-responsive metal-organic frameworks (MOFs) during environmental remediation are discussed in detail in this paper. MOFs are highly porous materials with generally high adsorption capacity of environmental pollutants. The incorporation of stimuli-responsive moieties in their structures confer them with additional properties such as being easily recovered and recyclability. Consequently, there is an increase in the use of stimuli-responsive MOFs during environmental remediation. Some researchers have successfully incorporated photoactive species into the structures of MOFs resulting in the formation of light-responsive composites. The presence of thermo-responsive polymeric units in the structure of an MOF make it to have physicochemical properties that are sensitive to temperature changes. The recovery of MOFs composites can be facilitated by the incorporation of magnetic nanoparticles into their structures. This review explores the utilisation of thermo-responsive MOFs, light-responsive MOFs and magnetic responsive MOFs during environmental remediation. In addition, challenges associated with the use of smart MOFs during the remediation of polluted environments are discussed in detail in this review as well as their future prospects. • Smart MOFs are efficient adsorbents for environmental remediation • Their physicochemical properties are responsive to stimuli • Light, temperature, and magnetic stimulations are usually involved in smart MOFs • Adsorption/desorption processes in smart MOFs are triggered by changes in stimuli • Smart MOF=based membranes have stimuli-regulated pore sizes

Conjugated Block Copolymers for Functional Nanostructures.

Conjugated polymers have been actively studied as an alternative to inorganic semiconductors for their unique optical and electrical properties and low-cost solution processability. However, typical conjugated polymer films contain numerous defects that negatively affect their transport properties, which remains a major issue despite much effort to develop ways to improve the molecular packing structure. In principle, conjugated block copolymers (BCPs) composed of a rod-type conjugated polymer and a coil-type insulating polymer can assemble into various types of ordered nanostructures based on the microphase segregation of two polymer blocks. However, such assembly typically requires a relatively large volume fraction of the coil block or modification of the rod block, both of which tend to impede charge transport. As an alternative, we and others have fabricated nanoscale assemblies of conjugated BCPs via solution-phase self-assembly, which can be used as building blocks for construction of extended nanoarrays of conjugated polymers. In particular, BCPs containing poly(3-hexylthiophene) (P3HT), a conjugated polymer widely used for its high hole mobility, form highly ordered and technologically relevant one-dimensional (1D) nanowires with controlled lengths. A range of well-defined assembly structures such as square plates, ribbons, vesicles, and helices have been prepared from various conjugated BCPs, resembling those of peptide self-assembly, forming diverse nanostructures through combinations of π-π stacking, hydrogen bonding, and hydrophobic interactions.When the self-assembly of P3HT BCPs takes place at an air-water interface, the initially formed polymer nanowires further assemble into hierarchical two-dimensional (2D) nanoarrays with solvent evaporation. The fluidic nature of the water subphase allows fabrication of highly ordered assembly structures from P3HT BCPs with high P3HT content. The ultrathin free-standing film integrated in a field effect transistor (FET) showed orders of magnitude higher current and hole mobility compared to that fabricated by conventional spin-coating. Furthermore, binary self-assembly of a P3HT BCP and quantum dots (QDs) at the air-water interface generates well-ordered 2D films of alternating P3HT nanowires and 1D QD arrays. Unlike coil-coil BCP systems, QDs reside at the interface between P3HT and coil blocks for a broad range of QD sizes due to the strong P3HT packing interactions and the flexible water subphase, forming tight p-n junctions for enhanced photocurrent. Incorporation of magnetic nanoparticles can further improve the degree of order, enabling fabrication of long-range order and direction-controlled P3HT nanoarrays through magnetic-field induced self-assembly.The conjugated BCP approach is highly modular and can be combined with various types of functional molecules, polymers, and nanoparticles, offering a powerful platform for fabrication of functional polymer nanostructures with desired morphologies and properties. This Account introduces recent advances in the self-assembly of π-conjugated BCPs, describes how they differ from prototypical coil-coil type BCPs, and discusses current issues and future outlooks.

SPION based magnetic PLGA nanofibers for neural differentiation of mesenchymal stem cells

Recently, magnetic platforms have been widely investigated in diagnostic, therapeutic and research applications due to certain properties, such as cell and tissue tracking and imaging, thermal therapy and being dirigible. In this study, the incorporation of magnetic nanoparticles (MNPs) in nanofibers has been proposed to combine the advantages of both nanofibers and MNPs to induce neural differentiation of mesenchymal stem cells. Magnetic poly (lactic-co-glycolic acid) nanofibers (containing 0%, 5% and 10% SPION) were fabricated and utilized as the matrix for the differentiation of mesenchymal stem cells (MSCs). Morphological, magnetic and mechanical properties were analyzed using FESEM, VSM and tensile test, respectively. The expression of neural markers (TUJ-1, NSE, MAP-2) was assessed quantitative and qualitatively utilizing RT-PCR and immunocytochemistry. Results confirmed the incorporation of MNPs in nanofibrous scaffold, presenting a saturation magnetization of 9.73 emu g−1. Also, with increase in magnetic particle concentration (0%–10%), tensile strength increased from 4.08 to 5.85 MPa, whereas the percentage of elongation decreased. TUJ-1 expression was 3.8 and 1.8 fold for 10% and 5% magnetic scaffold (versus non-magnetic scaffold) respectively, and the expression of NSE was 6.3 and 1.2-fold for 10% and 5%, respectively. Consequently, it seems that incorporation of magnetic biomaterial can promote the neural differentiation of MSCs, during which the augmentation of super paramagnetic iron oxide concentration from 0% to 10% accelerates the neural differentiation process.

Effect of External Magnetic Field on Bulk Heterojunction Polymer Solar Cells.

Polymer solar cells (PSCs) with a bulk heterojunction (BHJ) device structure have incredible advantages, such as low-cost fabrication and flexibility. However, the power conversion efficiency (PCE) of BHJ PSCs needs to be further improved to realize their practical applications. In this study, boosted PCEs from PSCs based on BHJ composites incorporated with Fe3 O4 magnetic nanoparticles (MNPs), aligned by an external magnetic field (EMF), are reported. It is found that the coercive electric field within the Fe3 O4 MNPs generated by the EMF has a strong and positive influence on the charge generation, which results in a more than 10% increase in free charge carriers. Moreover, the coercive electric field speeds up the charge carrier transport and suppresses charge carrier recombination within PSCs. In addition, a shortened extraction time makes charge carriers more likely to make it to the electrodes. As a result, more than 15% enhancement in PCE is observed from the PSCs based on the BHJ composite incorporated with the Fe3 O4 MNPs and the EMF as compared with that based on the BHJ composite thin film. This work indicates that the incorporation of MNPs and the EMF is a facile way to enhance the PCEs of PSCs.

MAGNETIC CHITOSAN NANOCOMPOSITES AS ADSORBENTS IN INDUSTRIAL WASTEWATER TREATMENT: A BRIEF REVIEW

In recent decades, the increasing demand for chemicals has led to producing large volumes of wastewater streams, which should be treated before their release into the environment. Chitosan, a marine polysaccharide derived from chitin, has recently attracted great attention as a promising adsorbent to eliminate ionic dyes and metals from industrial waste streams. Nevertheless, chitosan has its drawbacks, such as its rather weak mechanical properties, low surface area and difficult separation from final streams. The incorporation of magnetic nanoparticles into chitosan may be considered as one of the most effective remedies for the mentioned challenges. This paper addresses the efforts that have been recently made for the application of magnetic nanoparticles/chitosan nanocomposites (MCNCs) as adsorbents in wastewater treatment. In this regard, the synthesis methods, physicochemical properties, and the effects of operational conditions on the performance of MCNCs have been reviewed. The adsorption kinetics, isotherms, and mechanisms are also highlighted.

Assessing hyperthermia performance of hybrid textile filaments: The impact of different heating agents

The application of advanced textile materials functionalized with magnetic nanoparticles (MNP) has become increasingly important in tumor therapy. In this regard, the incorporation of MNP into polymeric filaments, so-called hybrid filaments, enables the development of magnetic heatable stents that, once implanted, are used to deliver therapeutic heat to the tumor site under the influence of an external alternating magnetic field (AMF). In this study, we investigate the hyperthermia performance of different hybrid filaments functionalized with MNP and discuss the relevant parameters influencing the heating efficiency such as MNP immobilization, agglomeration and magnetization as well as AMF settings. For this, three different MNP types (self-synthesized single domain MNP and two commercially available multi-domain MNP, BAYFERROX® and BNF-Starch) were incorporated in polypropylene filaments by melt spinning. Their heating efficiency was assessed in dependence of the AMF amplitude. Because of the blocking of Brownian rotation and bigger effective anisotropy constant caused by MNP agglomeration inside the filaments, the heating efficiency of all hybrid filaments was smaller than that of the corresponding MNP dispersed in water. Nevertheless, in all cases the heating efficiency increased with magnetic field amplitude. The highest specific loss power (SLP) values were reached for the self-synthesized particles at lower magnetic field amplitudes (<25 kA/m) and for BNF-Starch particles at high magnetic field amplitudes (>25 kA/m). This is caused by the higher anisotropy constant of the BNF-Starch particles and their collective magnetic response at higher magnetic field amplitudes.

Thermoresponsive magnetic/polymer composite nanoparticles for biomedical applications

Thermoresponsive magnetic/polymer composite nanoparticles (MPCNPs) possess unique properties for combined simultaneous application of magnetically induced targeted delivery of drugs to tumors, hyperthermia, controlled drug discharge and magnetic resonance imaging (MRI). In this regard, magnetic nanoparticles (MNPs), in particular Fe3O4 and γ-Fe2O3, are important because of their apparent biocompatibility and exclusive size-dependent qualities. Thermoresponsive polymers deliver controlled drug release, which is induced by the temperature above their lower critical solution temperature (LCST). Incorporation of MNPs into the thermoresponsive polymers structure provide combined benefits: (i) the magnetic component acts as heat source by means of magnetically assisted heating, which triggers drug release; (ii) preferential accumulation of drug loaded MPCNPs to the targeted locations is achieved by utilizing an external magnetic field; (iii) imaging and diagnostic can be done by MRI. In this article, formulation of a drug delivery system, based on ion γ-Fe2O3 MNPs and thermoresponsive polymer Poly(N-isopropylacrylamide) (PNIPAM) is presented. γ-Fe2O3 MNPs were synthesized by wet chemical method and γ-Fe2O3–PNIPAM composite nanoparticles were made by dispersion free-radical mechanism through polymerization of NIPAM. The synthesized MPCNPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA) and vibrating sample magnetometry (VSM). Anti-cancer drug, doxorubicin, was loaded into MPCNPs. The drug release profile was studied in-vitro under the influence of magnetically assisted heating conditions, when therapeutically substantial quantity of drug was released. Therefore, multimodal approach (magnetic drug targeting, simultaneous hyperthermia and controlled drug release) of cancer treatment by using anti-cancer drug loaded thermoresponsive magnetic/polymer composite nanoparticles can improve the efficacy of present cancer treatment.

Metamorphic barcodes based on lithographically defined microdots incorporating nanoparticles of phase change materials

Printed barcode lacks distributability as each barcode associated with sample cannot be divided when multiple copies of the same barcode are needed for forensic analysis. This article reports a metamorphic barcode with desired distributability to label objects (liquids or solids) in a covert and high-fidelity manner using polymer microdots containing a panel of phase change nanoparticles (low melting point metal or alloy). The microdots can be made with photolithography at large quantity or serial laser fabrication and have unique serialization numbers based on the melting characteristics of nanoparticles. The microdots can be distributed evenly in liquid or attached on various location of an object and decoded with differential scanning calorimeter. Incorporation of magnetic nanoparticles allows facile collection of polymer microdots with a magnet. The microdots are non-toxic and stable over one year without losing coding information and have higher large labeling capacity than other covert barcode systems.

Magnetic nanocomposite hydrogels and static magnetic field stimulate the osteoblastic and vasculogenic profile of adipose-derived cells

Exposure of cells to externally applied magnetic fields or to scaffolding materials with intrinsic magnetic properties (magnetic actuation) can regulate several biological responses. Here, we generated novel magnetized nanocomposite hydrogels by incorporation of magnetic nanoparticles (MNPs) into polyethylene glycol (PEG)-based hydrogels containing cells from the stromal vascular fraction (SVF) of human adipose tissue. We then investigated the effects of an external Static Magnetic Field (SMF) on the stimulation of osteoblastic and vasculogenic properties of the constructs, with MNPs or SMF alone used as controls. MNPs migrated freely through and out of the material following the magnetic gradient. Magnetically actuated cells displayed increased metabolic activity. After 1 week, the enzymatic activity of Alkaline Phosphatase (ALP), the expression of osteogenic markers (Runx2, Collagen I, Osterix), and the mineralized matrix deposition were all augmented as compared to controls. With magnetic actuation, strong activation of endothelial, pericytic and perivascular genes paralleled increased levels of VEGF and an enrichment in the CD31+ cells population. The stimulation of signaling pathways involved in the mechanotransduction, like MAPK8 or Erk, at gene and protein levels suggested an effect mediated through the mechanical stimulation. Upon subcutaneous implantation in mice, magnetically actuated constructs exhibited denser, more mineralized and faster vascularized tissues, as revealed by histological and micro-computed tomographic analyses. The present study suggests that magnetic actuation can stimulate both the osteoblastic and vasculogenic potentials of engineered bone tissue grafts, likely at least partially by mechanically stimulating the function of progenitor cells.

Spark Plasma Sintered Bulk Nanocomposites of Bi2Te2.7Se0.3 Nanoplates Incorporated Ni Nanoparticles with Enhanced Thermoelectric Performance.

Bi2Te3-based compounds are important near room temperature thermoelectric materials with commercial applications in thermoelectric modules. However, new routes leading to improved thermoelectric performance are highly desirable. Incorporation of superparamagnetic nanoparticles was recently proposed as a means to promote the thermoelectric properties of materials, but its feasibility has rarely been examined in mainstream thermoelectric materials. In this study, high quality single-crystalline Bi2Te2.7Se0.3 nanoplates and Ni nanoparticles were successfully synthesized by solvothermal and thermal decomposition methods, respectively. Bulk nanocomposites consisting of Bi2Te2.7Se0.3 nanoplates and superparamagnetic Ni nanoparticles were prepared by spark plasma sintering. It was found that incorporation of Ni nanoparticles simultaneously increased the carrier concentration and provided additional scattering centers, which resulted in enlarged electric conductivities and Seebeck coefficients. The greatly improved ZT was achieved due to the increase in power factor. Spark plasma sintered bulk nanocomposites of Bi2Te2.7Se0.3 nanoplates incorporated by 0.4 mol %Ni nanoparticles (in molar ratio) showed a figure-of-merit ZT of 0.66 at 425 K, equivalent to 43% increase when compared to pure Bi2Te2.7Se0.3 nanoplates. The results revealed that incorporation of magnetic nanoparticles could be an effective approach for promoting the thermoelectric performance of conventional semiconductors.

Integration of microbead DNA handling with optomagnetic detection in rolling circle amplification assays.

Rolling circle amplification (RCA) is a linear isothermal amplification technique that is widely applied in biomolecular assays due to its high specificity. Handling of a target sample using magnetic microbeads (MMBs) in a multi-step assay is appealing as the MMBs enable separation and transportation using an external magnet. Detection of amplicons using optomagnetic measurements of the rotational diffusion properties of magnetic nanoparticles (MNPs) is also appealing as it can be performed on any transparent sample container. Two strategies are described for integration of MMB sample handling in an RCA assay with on-chip optomagnetic detection of the amplification products. The first strategy relies on selective and irreversible release of the amplicons from the MMBs so that the binding of functionalized MNPs to the amplicons can be detected optomagnetically. The second strategy relies on the incorporation of MNPs into RCA products during RCA, followed by their separation on MMBs and subsequent optomagnetic detection upon release from the RCA products. Using MMB handling of RCA steps, the limits of detection (LODs) for a synthetic DNA target representative of Victoria Influenza type B were found to be between 4 and 20 pM with total assay times between 2 and 2.5 h. Without magnetic microbead sample handling, the LOD was 200 fM. The findings provide deeper insight into the use of magnetic microbeads as solid substrates to handle a DNA target for integration of RCA as well as other DNA-based assays. Graphical Abstract Schematic illustration of magnetic microbeads transporting a DNA target through the steps in a rolling circle amplification assay. Optomagnetic measurements detect the binding of magnetic nanoparticles to amplicons released from microbeads (top) or the pH-induced release of magnetic nanoparticles trapped in amplicons (bottom).

Magnetic hybrid of cyclodextrin nanosponge and polyhedral oligomeric silsesquioxane: Efficient catalytic support for immobilization of Pd nanoparticles.

For the first time a novel magnetic catalyst was prepared through hybridization of functionalized cyclodextrin nanosponges and octakis(3-chloropropyl)octasilsesquioxane followed by incorporation of Pd and magnetic nanoparticles. The resulting composite, was utilized as an efficient heterogeneous catalyst for promoting Sonogashira and Heck reactions in the absence of any ligand and co-catalyst under mild reaction condition. Comparison of the catalytic activities of the control catalysts and the catalyst confirmed that cyclodextrin nanosponges was more efficient support that cyclodextrin. Moreover, the hybrid catalyst showed superior catalytic activity compared to those obtained from the individual components, indicating the contribution of both hybrid components to the catalysis. Furthermore, it was found that incorporation of magnetic nanoparticles could improve the catalytic performance. The Study of the recyclability of the catalyst showed high recyclability of the catalyst as well as low Pd leaching.

Enhanced photocatalytic performance of magnetic multi-walled carbon nanotubes/cerium dioxide nanocomposite

An easily separated photocatalyst, magnetic multi-walled carbon nanotubes/cerium dioxide (MMWCNTs-CeO2) nanocomposite, has been successfully prepared by hydrothermal synthesis and subsequent loading of magnetic nanoparticles. The synthesized nanocomposite was characterized by scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, powder X-ray diffraction, and vibrating sample magnetometer. The characterization results indicated the successful synthesis of MMWCNTs-CeO2 nanocomposite. Photocatalytic degradation experiments were conducted to evaluate photocatalytic properties of MMWCNTs-CeO2 by using methylene blue (MB) as a model pollutant. After a light irradiation of two hours, relatively high degradation efficiency (97.5%) of MB was achieved by using MMWCNTs-CeO2 nanocomposite as photocatalyst in the presence of H2O2. The incorporation of magnetic nanoparticles could not only facilitate the separation of photocatalyst from the solution after treatment, but also enhance the photocatalytic degradation efficiency. The results of this study suggested that the synthesized MMWCNTs-CeO2 nanocomposite showed an attractive prospect for application in the treatment of organic wastewater.

Electrochemical study of magnetic nanogel designed for controlled release of chlorhexidine gluconate

Intensive care is required for patient with higher degree of burns as they are prone to sepsis mortality. Topical antimicrobials/antiseptics are the conventional treatment of choice with each having its limitation in terms of toxicity and effectiveness. Magnetic nanogel have long been studied for in vivo drug delivery in cancer treatment. Inspired by fact that incorporation of magnetic nanoparticles will enhance the antimicrobial properties of nanogel, we developed a chitosan-gelatin based polymer with dispersed magnetic Cobalt iron oxide nanoparticles for controlled release of chlorhexidine gluconate. MNPs were synthesized by co-precipitation method and confirmation of CoFe2O4 phase was done with XRD analysis. Nanogel was fabricated by solution casting method and further characterization to determine drug interaction with polymer and MNPs was performed using Fourier Transformed Infra-Red Spectroscopy, Scanning Electron Microscopy, and Electroanalytical methods including Cyclic Voltammetry, Square Wave Voltammetry and Electrochemical Impedance Spectroscopy. Results of the study indicate that electrochemical nature of nanogel is pH dependent and the drug release can be induced at pH ranging from 6 to 7. Findings of this study highlight potential of the synthesized nanogel in developing burn care treatment that enables on demand drug release in response to sepsis with changing pH and can be integrated with detection system due to the presence of MNPs in it.