Bimodal Nanoparticles Research Articles

Bifunctional folic acid targeted biopolymer Ag@NMOF nanocomposite [{Zn2 (1,4-bdc) 2 (DABCO)} n] as a novel theranostic agent for molecular imaging of colon cancer by SERS

Without a doubt, cancer and its negative impact on human health have created many hurdles for people across the world since conventional approaches have not offered a reliable ability in the eradication of cancer. As a result, finding novel approaches, like using bimodal nanoparticles as a potential nanocarrier in molecular imaging and cancer therapy, is remarkably required these days. In the present study, ex-situ (Ge) and in-situ (Gi) green synthesized silver (Ag) nanoparticles entrapped in metal-organic framework nanocomposites (NMOF) coated with folic acid (FA) targeted chitosan (CS) was successfully developed as a novel bifunctional nanocarrier for detection and treatment of colon cancer cells. Then nanocarriers, such as NMOF–CS–FA, Ge–Ag@NMOF–CS–FA, Gi-Ag@NMOF–CS–FA, and C–Ag@NMOF–CS–FA, were characterized via FT-IR, DLS, SERS, TEM, and SEM and results have potentially confirmed the quality and quantity of synthesized nanocomposites. The hydrodynamic diameters of NMOF-CS, Ge–Ag@NMOF-CS, Gi-Ag@NMOF-CS, and C–Ag@NMOF-CS specimens were measured at around 99.7 ± 10 nm, 110 ± 10 nm, 118 ± 10 nm, 115 ± 10 nm, respectively. Also, the PDI values less than 0.2 confirm the reliable distribution of these nanocomposites. Afterward, the cell viability assay was conducted on HCT116 and HGF cell lines for evaluating biocompatibility and targeting efficiency of nanocomposites; FA functionalized nanocomposites have intensively indicated better performance in cancer cells targeting and their inhibition, and IC50 was attained for 10 ng/mL of Ge–Ag@NMOF–CS–FA while non-targeted nanocarriers did not have toxicity more than 20 % on HCT116 colon cancer cells. Moreover, according to the results, the cell viability of HGF normal cells was at least 85 % after being exposed to different concentrations of nanocomposites for 24 h. This indicates that the synthesized nanocomposites do not have significant toxic effects on normal cells. The results indicate that this novel nanocomposite has the potential to effectively deliver drugs to cancer cells.

Numbers Matter: The Role of Cell Dose in the Treatment of Osteosarcoma Using Mesenchymal Stromal Cells as Cellular Vehicles

AbstractA promising approach enhancing osteosarcoma (OS) prognosis involves the combination of various techniques, such as chemo‐ and photodynamic therapy, delivered through nanocarriers for synergistic cell death. Among the potential candidates for improving drug accumulation at the tumor site, mesenchymal stromal cells (MSCs) exhibit a significant advantage due to their tumor‐homing ability and intracellular drug retention. This study evaluates the efficacy of chemo‐releasing and photoactive bimodal nanoparticles, kPCe6 NPs, delivered via MSCs. In vitro analyses show that cells internalize and retain kPCe6 NPs in a dose‐dependent manner and that kPCe6‐loaded cells induce massive tumor cell death in a tridimensional tumor model. Results from an in vivo orthotopic OS murine model show negligible tumor cell death upon peritumoral administration of two doses containing 106 loaded cells. To gain insight into this observation, this work investigates the role of cell dose in treatment efficacy. The results indicate that achieving a tumor reduction higher than 90% requires a substantial number of loaded cells, approximately 35% of the entire tumor mass, highlighting the criticality of the cell dose for the success of this therapeutic approach and its potential impact on clinical translation in OS patients, particularly when the number of tumor cells is limited.

Nanoparticle Tracking in Single‐Antiresonant‐Element Fiber for High‐Precision Size Distribution Analysis of Mono‐ and Polydisperse Samples

Accurate determination of the size distribution of nanoparticle ensembles remains a challenge in nanotechnology-related applications due to the limitations of established methods. Here, a microstructured fiber-assisted nanoparticle tracking analysis (FaNTA) realization is introduced that breaks existing limitations through the recording of exceptionally long trajectories of rapidly diffusing polydisperse nanoparticles, resulting in excellent sizing precision and unprecedented separation capabilities of bimodal nanoparticle mixtures. An effective-single-mode antiresonant-element fiber allows to efficiently confine nanoparticles in a light-guiding microchannel and individually track them over more than 1000 frames, while aberration-free imaging is experimentally confirmed by cross-correlation analysis. Unique features of the approach are (i) the highly precise determination of the size distribution of monodisperse nanoparticle ensembles (only 7% coefficient of variation) and (ii) the accurate characterization of individual components in a bimodal mixture with very close mean diameters, both experimentally demonstrated for polymer nanospheres. The outstanding performance of the FaNTA realization can be quantified by introducing a new model for the bimodal separation index. Since FaNTA is applicable to all types of nano-objects down to sub-20nm diameters, the method will improve the precision standard of mono- and polydisperse nanoparticle samples such as nano-plastics or extracellular vesicles.

Bimetallic Exsolved Heterostructures of Controlled Composition with Tunable Catalytic Properties.

In this paper, we show how the composition of bimetallic Fe-Ni exsolution can be controlled by the nature and concentration of oxygen vacancies in the parental matrix and how this is used to modify the performance of CO2-assisted ethane conversion. Mesoporous A-site-deficient La0.4Sr0.6-αTi0.6Fe0.35Ni0.05O3±δ (0 ≤ α ≤ 0.2) perovskites with substantial specific surface area (>40 m2/g) enabled fast exsolution kinetics (T < 500 °C, t < 1 h) of bimetallic Fe-Ni nanoparticles of increasing size (3-10 nm). Through the application of a multitechnique approach we found that the A-site deficiency determined the concentration of oxygen vacancies associated with iron, which controlled the Fe reduction. Instead of homogeneous bimetallic nanoparticles, the increasing Fe fraction from 37 to 57% led to the emergence of bimodal Fe/Ni3Fe systems. Catalytic tests showed superior stability of our catalysts with respect to commercial Ni/Al2O3. Ethane reforming was found to be the favored pathway, but an increase in selectivity toward ethane dehydrogenation occurred for the systems with a low metallic Fe fraction. The chance to control the reduction and growth processes of bimetallic exsolution offers interesting prospects for the design of advanced catalysts based on bimodal nanoparticle heterostructures.

Synthesis of orientated Ni0.89Fe0.11/polymer nanofibres with a bimodal nanoparticle size distribution by electrospinning and thermal processing

Orientated ferromagnetic Ni0.89Fe0.11 nanoparticle/polymer nanofibres were made by electrospinning a solution containing iron(III) nitrate nonahydrate, nickel(II) acetate tetrahydrate, polyvinylpyrrolidone, and acetic acid in methanol and thermally processed in Ar and then 95%Ar:5%H2 up to 620 °C. There was a distribution in nanofibre widths after electrospinning with wider (average width 440 nm) and some thinner (average width 120 nm) nanofibres. The nanofibre width distribution decreased after heat treatment and the average nanofibre width reduced to 160 nm. A bimodal Ni0.89Fe0.11 nanoparticle size distribution was found where there were large surface nanoparticles with a mean diameter of 35 nm and small inner nanoparticles with a 5 nm mean diameter. There was a small spin-disordered shell magnetization that was only ~2% of the total 5 K saturation magnetization and a characteristic spin-freezing temperature of 21 K. The high field magnetization was large, and it reached 41.7 Am2/kg at 5 K.

Influence of particle size of mesoporous silica composite nanoparticles coated with pH/temperature responsive copolymer on ibuprofen release behaviors

The bimodal mesoporous silicas nanoparticles (BMMs) with small size of 20–50 nm and mesoporous silicas nanoparticles (MSNs) with large sizes from 80 nm to 280 nm were synthesized using sol–gel method. These functionalized mesoporous silicas composites with different sizes were acquired by environmental responsive (pH/temperature) copolymer coated onto the mesoporous silica hosts via the seed polymerization method. The structural features and textual parameters of resultant samples were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, N2 adsorption–desorption isotherms, thermogravimetric analyses, FT-IR, DLS, SAXS technologies, indicating that copolymer was successfully coated on the mesoporous silicas. Meanwhile, functionalized mesoporous silicas composites as drug carries were used to explore the pH/temperature responsive efficiency. These results showed that compared with the blank mesoporous silicas nanoparticles, mesoporous silicas composites realized a reduced initial burst release. In particular, the particle size of mesoporous silicas composites effects on the release behaviors were found that the smaller composite nanoparticles with short mesoporous channels exhibited highly pH/temperature response compared to the larger composite nanoparticles with long mesoporous channels. Meanwhile, their IBU-release kinetic profiles followed Korsmeyer–Peppas model. Moreover, the toxicity of mesoporous silicas composites was evaluated in vitro. It found that the particle size of mesoporous silicas composites was essential for its cytotoxicity.

RuCo alloy bimodal nanoparticles embedded in N-doped carbon: a superior pH-universal electrocatalyst outperforms benchmark Pt for the hydrogen evolution reaction

Benefiting from the unique structure and composition, a superior hybrid composed of RuCo alloy bimodal nanoparticles embedded in N-doped carbon exhibits exceptional HER activities in all pH conditions, outperforming the benchmark Pt/C catalyst.

The effect of pulse duration on nanoparticle generation in pulsed laser ablation in liquids: insights from large-scale atomistic simulations.

The generation of colloidal solutions of chemically clean nanoparticles through pulsed laser ablation in liquids (PLAL) has evolved into a thriving research field that impacts industrial applications. The complexity and multiscale nature of PLAL make it difficult to untangle the various processes involved in the generation of nanoparticles and establish the dependence of nanoparticle yield and size distribution on the irradiation parameters. Large-scale atomistic simulations have yielded important insights into the fundamental mechanisms of ultrashort (femtoseconds to tens of picoseconds) PLAL and provided a plausible explanation of the origin of the experimentally observed bimodal nanoparticle size distributions. In this paper, we extend the atomistic simulations to short (hundreds of picoseconds to nanoseconds) laser pulses and focus our attention on the effect of the pulse duration on the mechanisms responsible for the generation of nanoparticles at the initial dynamic stage of laser ablation. Three distinct nanoparticle generation mechanisms operating at different stages of the ablation process and in different parts of the emerging cavitation bubble are identified in the simulations. These mechanisms are (1) the formation of a thin transient metal layer at the interface between the ablation plume and water environment followed by its decomposition into large molten nanoparticles, (2) the nucleation, growth, and rapid cooling/solidification of small nanoparticles at the very front of the emerging cavitation bubble, above the transient interfacial metal layer, and (3) the spinodal decomposition of a part of the ablation plume located below the transient interfacial layer, leading to the formation of a large population of nanoparticles growing in a high-temperature environment through inter-particle collisions and coalescence. The coexistence of the three distinct mechanisms of the nanoparticle formation at the initial stage of the ablation process can be related to the broad nanoparticle size distributions commonly observed in nanosecond PLAL experiments. The strong dependence of the nanoparticle cooling and solidification rates on the location within the low-density metal-water mixing region has important implications for the long-term evolution of the nanoparticle size distribution, as well as for the ability to quench the nanoparticle growth or dope them by adding surface-active agents or doping elements to the liquid environment.

Magnetic Nanoplatelets for High Contrast Cardiovascular Imaging by Magnetically Modulated Optical Coherence Tomography

AbstractThe front cover artwork is provided by Universidad Autónoma de Madrid, Spain, the Jožef Stefan Institute Ljubljana, Slovenia, and the university hospitals Gregorio Marañon and La Princesa in Madrid, Spain. The image shows an occlusion in an artery which is marked by bimodal nanoparticles and detected by optical coherence tomography, while being exposed to a magnetic field, thereby improving the signal. Read the full text of the Article at 10.1002/cptc.201900071.

Front Cover: Magnetic Nanoplatelets for High Contrast Cardiovascular Imaging by Magnetically Modulated Optical Coherence Tomography (ChemPhotoChem 7/2019)

The Front Cover shows an occlusion in an artery which is marked by bimodal nanoparticles and detected by optical coherence tomography, while being exposed to a magnetic field, thereby improving the signal. More information can be found in the Article by J. Hu et al. on page 529 in Issue 7, 2019 (DOI: 10.1002/cptc.201900071).

DNA-enabled rational design of fluorescence-Raman bimodal nanoprobes for cancer imaging and therapy

Recently, surface-enhanced Raman scattering nanoprobes have shown tremendous potential in oncological imaging owing to the high sensitivity and specificity of their fingerprint-like spectra. As current Raman scanners rely on a slow, point-by-point spectrum acquisition, there is an unmet need for faster imaging to cover a clinically relevant area in real-time. Herein, we report the rational design and optimization of fluorescence-Raman bimodal nanoparticles (FRNPs) that synergistically combine the specificity of Raman spectroscopy with the versatility and speed of fluorescence imaging. DNA-enabled molecular engineering allows the rational design of FRNPs with a detection limit as low as 5 × 10−15 M. FRNPs selectively accumulate in tumor tissue mouse cancer models and enable real-time fluorescence imaging for tumor detection, resection, and subsequent Raman-based verification of clean margins. Furthermore, FRNPs enable highly efficient image-guided photothermal ablation of tumors, widening the scope of the NPs into the therapeutic realm.

Hydrophilic Quantum Dots Functionalized with Gd(III)-DO3A Monoamide Chelates as Bright and Effective T1-weighted Bimodal Nanoprobes

Magnetic resonance imaging (MRI) is a powerful non-invasive diagnostic tool that enables distinguishing healthy from pathological tissues, with high anatomical detail. Nevertheless, MRI is quite limited in the investigation of molecular/cellular biochemical events, which can be reached by fluorescence-based techniques. Thus, we developed bimodal nanosystems consisting in hydrophilic quantum dots (QDs) directly conjugated to Gd(III)-DO3A monoamide chelates, a Gd(III)-DOTA derivative, allowing for the combination of the advantages of both MRI and fluorescence-based tools. These nanoparticulate systems can also improve MRI contrast, by increasing the local concentration of paramagnetic chelates. Transmetallation assays, optical characterization, and relaxometric analyses, showed that the developed bimodal nanoprobes have great chemical stability, bright fluorescence, and high relaxivities. Moreover, fluorescence correlation spectroscopy (FCS) analysis allowed us to distinguish nanosystems containing different amounts of chelates/QD. Also, inductively coupled plasma optical emission spectrometry (ICP – OES) indicated a conjugation yield higher than 75%. Our nanosystems showed effective longitudinal relaxivities per QD and per paramagnetic ion, at least 5 times [per Gd(III)] and 100 times (per QD) higher than the r1 for Gd(III)-DOTA chelates, suitable for T1-weighted imaging. Additionally, the bimodal nanoparticles presented negligible cytotoxicity, and efficiently labeled HeLa cells as shown by fluorescence. Thus, the developed nanosystems show potential as strategic probes for fluorescence analyses and MRI, being useful for investigating a variety of biological processes.

Investigation of structural, magnetic and luminescent properties of weakly-doped ZnO Cu nanopowders, produced by the pulsed electron beam evaporation

Abstract Nanopowders and coatings of pure and Cu-doped ZnO were prepared by the pulsed electron beam evaporation method. The results of X-ray diffraction demonstrated that all samples have a single-phase ZnO hexagonal wurtzite type structure. The SEM images highlighted that pure and Cu-doped ZnO samples have bimodal nanoparticle shapes with an average particle size of 40 nm-5 μm. The magnetic hysteresis loop of pure ZnO nanoparticles at room temperature revealed a saturation magnetization of 0.044 emu/g in a vacuum and 0.027emu/g in air. The hysteresis loops of Zn0.9978Cu0.0022O and Zn0.9965Cu0.0035O samples indicated similar magnetic properties with the saturation magnetization of 0.037 and 0.012 emu/g and coercivity of about zero and ∼100 Oe, respectively. The correlation between the concentration of structural defects (oxygen vacancies) and the ferromagnetic behavior of nanopowders are presented. The dependences of the integral intensity of the green and the orange bands of photoluminescence spectra and the magnetization on the copperdoping level are considered and their correlation is established.

Simulated Measurements of the Magnetic Behavior of New Dual-Mode Nanosized Contrast Agents

Aim of this work was to perform simulated measurements of the magnetic behavior of a novel class of bimodal nanosized contrast agents (CAs), made of a silica core covered by smaller superparamagnetic nanoparticles (NPs) and designed to be detected through both ultrasound and magnetic resonance imaging (MRI), in order to compare their performance in terms of MRI signal enhancement with that of the superparamagnetic NPs alone. The considered bimodal nanocomposites consisted of 330-nm silica nanospheres covered by either superparamagnetic iron oxide NPs or dumbbell-like FePt-IO nanocrystals. We simulated the MRI signal generated by each of the considered CAs during a brain venography in standard clinical conditions. Quantitative assessments of signal enhancement were carried out as a function of the main model parameters. The performed numerical simulations showed that the magnetic response of the novel nanocomposites was similar or better compared to that of the superparamagnetic NPs alone for echo times longer than 20 ms, leading to an easier detection of smaller vessels. Obtained results suggest that the bimodal NPs have an exciting potential for the development of innovative clinical protocols for multimodal imaging, combining quantitative measurements of cerebral blood flow and targeted molecular imaging of specific diseases.

Regulated transparent insulation for greenhouse covers through the use of tailor-made bimodal nanoparticle formations

Regulated transparent insulation for greenhouse covers through the use of tailor-made bimodal nanoparticle formations

Highly fluorescent and superparamagnetic nanosystem for biomedical applications

This work reports on highly fluorescent and superparamagnetic bimodal nanoparticles (BNPs) obtained by a simple and efficient method as probes for fluorescence analysis and/or contrast agents for MRI. These promising BNPs with small dimensions (ca. 17 nm) consist of superparamagnetic iron oxide nanoparticles (SPIONs) covalently bound with CdTe quantum dots (ca. 3 nm). The chemical structure of the magnetic part of BNPs is predominantly magnetite, with minor goethite and maghemite contributions, as shown by Mössbauer spectroscopy, which is compatible with the x-ray diffraction data. Their size evaluation by different techniques showed that the SPION derivatization process, in order to produce the BNPs, does not lead to a large size increase. The BNPs saturation magnetization, when corrected for the organic content of the sample, is ca. 68 emu g−1, which is only slightly reduced relative to the bare nanoparticles. This indicates that the SPION surface functionalization does not change considerably the magnetic properties. The BNP aqueous suspensions presented stability, high fluorescence, high relaxivity ratio (r2/r1 equal to 25) and labeled efficiently HeLa cells as can be seen by fluorescence analysis. These BNP properties point to their applications as fluorescent probes as well as negative T2-weighted MRI contrast agents. Moreover, their potential magnetic response could also be used for fast bioseparation applications.

Generation of Subsurface Voids, Incubation Effect, and Formation of Nanoparticles in Short Pulse Laser Interactions with Bulk Metal Targets in Liquid: Molecular Dynamics Study.

The ability of short pulse laser ablation in liquids to produce clean colloidal nanoparticles and unusual surface morphology has been employed in a broad range of practical applications. In this paper, we report the results of large-scale molecular dynamics simulations aimed at revealing the key processes that control the surface morphology and nanoparticle size distributions by pulsed laser ablation in liquids. The simulations of bulk Ag targets irradiated in water are performed with an advanced computational model combining a coarse-grained representation of liquid environment and an atomistic description of laser interaction with metal targets. For the irradiation conditions that correspond to the spallation regime in vacuum, the simulations predict that the water environment can prevent the complete separation of the spalled layer from the target, leading to the formation of large subsurface voids stabilized by rapid cooling and solidification. The subsequent irradiation of the laser-modified surface is found to result in a more efficient ablation and nanoparticle generation, thus suggesting the possibility of the incubation effect in multipulse laser ablation in liquids. The simulations performed at higher laser fluences that correspond to the phase explosion regime in vacuum reveal the accumulation of the ablation plume at the interface with the water environment and the formation of a hot metal layer. The water in contact with the metal layer is brought to the supercritical state and provides an environment suitable for nucleation and growth of small metal nanoparticles from metal atoms emitted from the hot metal layer. The metal layer itself has limited stability and can readily disintegrate into large (tens of nanometers) nanoparticles. The layer disintegration is facilitated by the Rayleigh–Taylor instability of the interface between the higher density metal layer decelerated by the pressure from the lighter supercritical water. The nanoparticles emerging from the layer disintegration are rapidly cooled and solidified due to the interaction with water environment, with a cooling rate of ∼2 × 1012 K/s observed in the simulations. The computational prediction of two distinct mechanisms of nanoparticle formation yielding nanoparticles with different characteristic sizes provides a plausible explanation for the experimental observations of bimodal nanoparticle size distributions in laser ablation in liquids. The ultrahigh cooling and solidification rates suggest the possibility for generation of nanoparticles featuring metastable phases and highly nonequilibrium structures.

Synthesis and characterization of a bimodal nanoparticle based on the host-guest self-assembly for targeted cellular imaging

Multimodal imaging provides distinct advantages over traditional single modal imaging. The combined modalities of magnetic resonance imaging (MRI) and near-infrared imaging (NIR), in particular, provide a powerful tool for tumor diagnosis. In this study, a bimodal MRI and NIR self-assembled supramolecular nanoparticle was developed via the self-assembly of host-guest interactions between hyaluronic acid–β-cyclodextrin (HA–CD) and amantadine (Ad)-modified imaging agents (Gd–DOTA and NIR cyanine dye Cy7). The supramolecular HA–CD–GC nanoparticles (NPs) were characterized by transmission electron microscopy (TEM), Zeta potential, and dynamic light-scattering (DLS) experiments. The relaxivity and fluorescent properties of the NPs were also determined. HA–CD–GC NPs exhibited an enhanced relaxivity of 11.4mM−1S−1, which was three-fold higher than that of clinical Gd3+-chelated complex, for MRI imaging. Moreover, HA–CD–GC NPs displayed excellent fluorescence. In addition, HA–CD–GC NPs were internalized into tumor cells via HA-receptor CD44-mediated endocytosis. Therefore, the self-assembled HA–CD–GC NPs are effective targeted tumor cell imaging systems and have potential applications in cancer diagnosis and treatment.

Silica-Based Nanoparticles as Bifunctional and Bimodal Imaging Contrast Agents.

New bifunctional and bimodal nanoparticles (NPs) have been elaborated and characterised. They are based on silica NPs that incorporate a silylated ruthenium tris-bipyridine complex. The resulting suspension of amine-modified NPs with diameters of 20 nm was post-functionalised with a stable gadolinium ion complex. Interest in these NPs lies mainly in the confinement of optical and magnetic imaging agents (Ru and Gd complexes, respectively) within the NP volume. Their potential use as a bimodal probe (luminescence/magnetic resonance imaging) and theranostic agent (photodynamic therapy/imaging) is described. The biological potential of these NPs has been studied on HCT-116 cells and microscopy and cytotoxicity results are given.

Interactions of Bimodal Magnetic and Fluorescent Nanoparticles Based on Carbon Quantum Dots and Iron-Carbon Nanocomposites with Cell Cultures.

Interactions of bimodal (fluorescent and magnetic) nanoparticles with HeLa cells were studied. The nanoparticles, characterized by high magnetic moment and relaxing capacity, exhibited fluorescence sufficient for their use as labels in confocal microscopy and flow cytometry. Penetration of these nanoparticles into the cell depended on their surface charge: positively charged nanoparticles of this structure penetrated inside, while negatively charged particles were not found in the cells.