Engineered nanoparticles for biomolecular imaging

Synergistic action of sumatriptan delivery and targeting magnesium deficiency using green, pH-responsive MgO nanoparticles synthesized from mahua flower extracts

Magnesium oxide (MgO) nanoparticles were green synthesized using mahua (Madhuca longifolia) flower extracts by solvent evaporation and characterized by UV-visible spectroscopy, X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray analysis (EDX). The drug loading of sumatriptan succinate (SS), an anti-migraine drug, was optimized using MINITAB's response surface methodology (RSM) Box Behnken model (BBD) model. The investigation of drug adsorption and release kinetics was further conducted using the optimized set obtained through RSM. The optimized parameters consisted of 23.53 mg of nanoparticles, a loading time of 6 h, and a pH of 9, yielding the experimental drug loading efficiency ~47%. The primary objective of this study is to investigate the potential of utilizing these green synthesized MgO nanoparticles for a dual purpose. The primary objective of this study is to investigate the viability of utilizing MgO nanoparticles synthesized through green route for the delivery of an anti-migraine medication. Additionally, the study aims to examine the degradation of these nanoparticles at physiological pH levels, with the intention of potentially enhancing cellular absorption. The investigation involved the assessment of drug release kinetics using various mathematical models, with a focus on the release of SS from MgO nanoparticles. This evaluation was conducted at different pH levels, specifically pH 5, 7, and 9. It has been found that the SS release increases as pH decreases, which is attributed to the dissolution of MgO nanoparticles, which therefore exhibits varied behavior at different pHs. The confirmation of the degradation of the green synthesized MgO nanoparticles was achieved through the execution of a degradation study, followed by the analysis of the obtained samples using FESEM and EDS. At neutral, the release data obtained adhered to the Higuchi model, which suggests that the release of the drug is based on diffusion. This finding is particularly advantageous for the controlled release of an anti-migraine drug. The results obtained from the study indicate that MgO nanoparticles have the potential to serve as a significant component in drug delivery systems, specifically as drug carriers. Attachment of SS over MgO nanoparticles to form SS loaded MgO nanoparticles and its possible working mechanism.

Surface modification potentials of cell membrane-based materials for targeted therapies: a chemotherapy-focused review

Nanotechnology has significant potential for cancer management at all stages, including prevention, diagnosis and treatment. In therapeutic applications, nanoparticles (NPs) have biological stability, targeting and body-clearance issues. To overcome these difficulties, biomimetic or cell membrane-coating methods using immune cell membranes are advised. Macrophage or neutrophil cell membrane-coated NPs may impede cancer progression in malignant tissue. Immune cell surface proteins and their capacity to maintain activity after membrane extraction and NP coating determine NP functioning. Immune cell surface proteins may offer NPs higher cellular interactions, blood circulation, antigen recognition for targeting, progressive drug release and reduced in vivo toxicity. This article examines nano-based systems with immune cell membranes, their surface modification potential, and their application in cancer treatment.

Tannic-acid-mediated synthesis and characterization of magnetite-gold nanoplatforms for photothermal therapy

Aim: The design of new hybrid nanoplatforms (HNPs) through the innovative and eco-friendly use of tannic acid (TA) for the synthesis and stabilization of the nanoplatforms. Materials & methods: The size, morphology, composition and magnetic and plasmonic properties of HNPs were investigated together with their ability to generate heat under laser irradiation and the hemotoxicity to explore their potential use for biomedical applications. Results & conclusion: The use of TA allowed the synthesis of the HNPs by adopting a simple and green method. The HNPs preserved the peculiar properties of both magnetic and plasmonic nanoparticles and did not show any hemotoxic effect.

A self-healing magneto-responsive nanocellulose ferrogel and flexible soft strain sensor

Crosslinks are the building blocks of hydrogels and play an important role in their overall properties. They may either be reversible and dynamic allowing for autonomous self-healing properties, or permanent and static resulting in robustness and mechanical strength. Hence, a combination of crosslinks is often required to engineer the 3D network of hydrogels with both autonomous self-healing and required robustness for strain sensing application; however, this complicates the fabrication of such hydrogels. The facile, yet versatile, approach used in this study is to forgo the use of extra crosslinks and instead rely solely on the properties of magnetic nanocellulose to fabricate a tough, stretchy, yet magneto-responsive, ionic conductive ferrogel for strain sensing. The ferrogel also gives stimuli-free and autonomous self-healing capacity, as well as the ability to monitor real-time strain under external magnetic actuation. The ferrogel also functions as a touch-screen pen. Based on our findings, this study has the potential to advance the rational design of multifunctional hydrogels, with applications in soft and flexible strain sensors, health monitoring and soft robotics.

Starch-g-Acrylic Acid/Magnetic Nanochitin Self-Healing Ferrogels as Flexible Soft Strain Sensors

Mechanically robust ferrogels with high self-healing ability might change the design of soft materials used in strain sensing. Herein, a robust, stretchable, magneto-responsive, notch insensitive, ionic conductive nanochitin ferrogel was fabricated with both autonomous self-healing and needed resilience for strain sensing application without the need for additional irreversible static chemical crosslinks. For this purpose, ferric (III) chloride hexahydrate and ferrous (II) chloride as the iron source were initially co-precipitated to create magnetic nanochitin and the co-precipitation was confirmed by FTIR and microscopic images. After that, the ferrogels were fabricated by graft copolymerisation of acrylic acid-g-starch with a monomer/starch weight ratio of 1.5. Ammonium persulfate and magnetic nanochitin were employed as the initiator and crosslinking/nano-reinforcing agents, respectively. The ensuing magnetic nanochitin ferrogel provided not only the ability to measure strain in real-time under external magnetic actuation but also the ability to heal itself without any external stimulus. The ferrogel may also be used as a stylus for a touch-screen device. Based on our findings, our research has promising implications for the rational design of multifunctional hydrogels, which might be used in applications such as flexible and soft strain sensors, health monitoring, and soft robotics.

Rare-Earth-Metal (Nd3+, Ce3+ and Gd3+)-Doped CaF2: Nanoparticles for Multimodal Imaging in Biomedical Applications

Here, we describe the synthesis of a novel type of rare-earth-doped nanoparticles (NPs) for multimodal imaging, by combining the rare-earth elements Ce, Gd and Nd in a crystalline host lattice consisting of CaF2 (CaF2: Ce, Gd, Nd). CaF2: Ce, Gd, Nd NPs are small (15-20 nm), of uniform shape and size distribution, and show good biocompatibility and low immunogenicity in vitro. In addition, CaF2: Ce, Gd, Nd NPs possess excellent optical properties. CaF2: Ce, Gd, Nd NPs produce downconversion emissions in the second near-infrared window (NIR-II, 1000-1700 nm) under 808 nm excitation, with a strong emission peak at 1056 nm. Excitation in the first near- infrared window (NIR-I, 700-900 nm) has the advantage of deeper tissue penetration power and reduced autofluorescence, compared to visible light. Thus, CaF2: Ce, Gd, Nd NPs are ideally suited for in vivo fluorescence imaging. In addition, the presence of Gd3+ makes the NPs intrinsically monitorable by magnetic resonance imaging (MRI). Moreover, next to fluorescence and MR imaging, our results show that CaF2: Ce, Gd, Nd NPs can be used as imaging probes for photoacoustic imaging (PAI) in vitro. Therefore, due to their biocompatibility and suitability as multimodal imaging probes, CaF2: Ce, Gd, Nd NPs exhibit great potential as a traceable imaging agent in biomedical applications.

Advances of engineered extracellular vesicles-based therapeutics strategy

Extracellular vesicles (EVs) are a heterogeneous population of lipid bilayer membrane-bound vesicles which encapsulate bioactive molecules, such as nucleic acids, proteins, and lipids. They mediate intercellular communication through transporting internally packaged molecules, making them attractive therapeutics carriers. Over the last decades, a significant amount of research has implied the potential of EVs servings as drug delivery vehicles for nuclear acids, proteins, and small molecular drugs. However, several challenges remain unresolved before the clinical application of EV-based therapeutics, including lack of specificity, stability, biodistribution, storage, large-scale manufacturing, and the comprehensive analysis of EV composition. Technical development is essential to overcome these issues and enhance the pre-clinical therapeutic effects. In this review, we summarize the current advancements in EV engineering which demonstrate their therapeutic potential.

3D bioprinting of nanoparticle-laden hydrogel scaffolds with enhanced antibacterial and imaging properties

Biomaterial-associated microbial contaminations in biologically conducive three-dimensional (3D) tissue-engineered constructs have significantly limited the clinical applications of scaffold systems. To prevent such infections, antimicrobial biomaterials are rapidly evolving. Yet, the use of such materials in bioprinting-based approaches of scaffold fabrication has not been examined. This study introduces a new generation of bacteriostatic gelatin methacryloyl (GelMA)-based bioinks, incorporated with varying doses of antibacterial superparamagnetic iron oxide nanoparticles (SPIONs). The SPION-laden GelMA scaffolds showed significant resistance against the Staphylococcus aureus growth, while providing a contrast in magnetic resonance imaging. We simulated the bacterial contamination of cellular 3D GelMA scaffolds in vitro and demonstrated the significant effect of functionalized scaffolds in inhibiting bacterial growth, while maintaining cell viability and growth. Together, these results present a new promising class of functionalized bioinks to 3D bioprint tissue-engineered scaffold with markedly enhanced properties for the use in a variety of in vitro and clinical applications.

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Functionalized bioinks with bacteriostatic properties are developed and thoroughly characterized

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The 200 μg/mL group yielded an optimal balance of printed scaffold properties

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Incorporating nanoparticle also enabled noninvasive imaging of the bioprinted scaffold

Synthesis, characterization, in vitro cytotoxicity and DNA interaction studies of antioxidant ferulic acid loaded on γ-Fe2O3@SiO2 nanoparticles

In this investigation, Fe₃O₄ magnetic nanoparticles (MNPs) were prepared via a chemical coprecipitation reaction, and the surface of Fe₃O₄ MNPs was coated with silica by a sol-gel process. The surface of Fe₃O₄@SiO₂ MNPs was modified by an antioxidant agent, trans-ferulic acid, to achieve water-soluble MNPs for biological applications. Fourier transform infrared spectroscopy (FT-IR) showed that the MNPs were successfully coated with SiO₂ and ferulic acid (FA) ligand. The morphology of γ-Fe₂O₃@SiO₂-FA MNPs was found to be spherical in images of transmission electron microscopy (TEM) and showed a uniform size distribution with an average diameter of 21 nm. The in vitro cytotoxic activity of γ-Fe₂O₃@SiO₂-FA MNPs and FA were investigated against the human cancer cells (MCF-7, PC-3, U-87 MG, A-2780, and A-549) by MTT colorimetric assay. The cytotoxic effect of MNPs on all cancer cell lines was several times of magnitude higher compared to free FA except for A-549 cell lines. Furthermore, in vitro DNA binding studies were investigated by UV-vis and circular dichroism spectroscopies.

Tissue engineered drug delivery vehicles: Methods to monitor and regulate the release behavior

Tissue engineering is a rapidly evolving, multidisciplinary field that aims at generating or regenerating 3D functional tissues for in vitro disease modeling and drug screening applications or for in vivo therapies. A variety of advanced biological and engineering methods are increasingly being used to further enhance and customize the functionality of tissue engineered scaffolds. To this end, tunable drug delivery and release mechanisms are incorporated into tissue engineering modalities to promote different therapeutic processes, thus, addressing challenges faced in the clinical applications. In this review, we elaborate the mechanisms and recent developments in different drug delivery vehicles, including the quantum dots, nano/micro particles, and molecular agents. Different loading strategies to incorporate the therapeutic reagents into the scaffolding structures are explored. Further, we discuss the main mechanisms to tune and monitor/quantify the release kinetics of embedded drugs from engineered scaffolds. We also survey the current trend of drug delivery using stimuli driven biopolymer scaffolds to enable precise spatiotemporal control of the release behavior. Recent advancements, challenges facing current scaffold-based drug delivery approaches, and areas of future research are discussed.

Potential toxicity of nickel nano and microparticles on the reproductive system of female rats—a comparative time-dependent study

Increased application of engineered nanoparticles in different sectors viz. agriculture, commerce, industry, and medicine has raised serious public health issues. Nanoparticles of nickel have been increasingly used as catalysts, conductive pastes, adhesives, nanowires, and nanofilters. Human and animal exposure to these particles may cause toxicity in different organs/systems. Studies made in the past had demonstrated their toxicity in liver, kidney, and lungs. However, their reproductive effects remain poorly understood. Therefore, the present study on reproductive toxicity of nickel nanoparticles (<30 nm) was executed in female Wistar rats. A comparison of results obtained in nickel microparticle-treated rats was also made. Rats were administered nano and microparticles through gavage at a dosage of 5 mg/kg body weight each for two exposure periods; that is, 15 and 30 days. Ovaries removed from these rats were analyzed to study the effects of nickel bioaccumulation on synthesis of steroid hormones, lipid peroxidation, apoptosis, and oxidative stress. Structural changes were monitored through histopathological and ultrastructural observations. The present study showed exposure time-dependent differences in the toxicity of nickel nano and microparticles in the ovary of rats. Nano nickel was cumulative in the ovaries. It affected steroidogenesis. Further, increased generation of reactive oxygen species and enhanced oxidative stress may have contributed to cytotoxicity. It was concluded that exposure to nano nickel might induce irreversible damage in the ovaries of rat.

Metallodrugs in cancer nanomedicine

Metal complexes are extensively used for cancer therapy. The multiple variables available for tuning (metal, ligand, and metal-ligand interaction) offer unique opportunities for drug design, and have led to a vast portfolio of metallodrugs that can display a higher diversity of functions and mechanisms of action with respect to pure organic structures. Clinically approved metallodrugs, such as cisplatin, carboplatin and oxaliplatin, are used to treat many types of cancer and play prominent roles in combination regimens, including with immunotherapy. However, metallodrugs generally suffer from poor pharmacokinetics, low levels of target site accumulation, metal-mediated off-target reactivity and development of drug resistance, which can all limit their efficacy and clinical translation. Nanomedicine has arisen as a powerful tool to help overcome these shortcomings. Several nanoformulations have already significantly improved the efficacy and reduced the toxicity of (chemo-)therapeutic drugs, including some promising metallodrug-containing nanomedicines currently in clinical trials. In this critical review, we analyse the opportunities and clinical challenges of metallodrugs, and we assess the advantages and limitations of metallodrug delivery, both from a nanocarrier and from a metal-nano interaction perspective. We describe the latest and most relevant nanomedicine formulations developed for metal complexes, and we discuss how the rational combination of coordination chemistry with nanomedicine technology can assist in promoting the clinical translation of metallodrugs.

Theranostic applications of stimulus-responsive systems based on Fe2O3

According to the interaction of nanoparticles with biological systems, enthusiasm for nanotechnology in biomedical applications has been developed in the past decades. Fe2O3 nanoparticles, as the most stable iron oxide, have special merits that make them useful widely for detecting diseases, therapy, drug delivery, and monitoring the therapeutic process. This review presents the fabrication methods of Fe2O3-based materials and their photocatalytic and magnetic properties. Then, we highlight the application of Fe2O3-based nanoparticles in diagnosis and imaging, different therapy methods, and finally, stimulus-responsive systems, such as pH-responsive, magnetic-responsive, redox-responsive, and enzyme-responsive, with an emphasis on cancer treatment. In addition, the potential of Fe2O3 to combine diagnosis and therapy within a single particle called theranostic agent will be discussed.

Metal-Organic Frameworks for Bioimaging: Strategies and Challenges

Metal-organic frameworks (MOFs), composited with metal ions and organic linkers, have become promising candidates in the biomedical field own to their unique properties, such as high surface area, pore-volume, tunable pore size, and versatile functionalities. In this review, we introduce and summarize the synthesis and characterization methods of MOFs, and their bioimaging applications, including optical bioimaging, magnetic resonance imaging (MRI), computed tomography (CT), and multi-mode. Furthermore, their bioimaging strategies, remaining challenges and future directions are discussed and proposed. This review provides valuable references for the designing of molecular bioimaging probes based on MOFs.

Biocompatibility Evaluation of Hollow Pollen Grains/Fe3 O4 Nanoparticles Composites as Potential Medical Devices

Recently, pollen grains (PGs) have been introduced as drug carriers and scaffolding building blocks. This study aimed to assess the in-vitro biocompatibility of Pistacia vera L. hollow PGs/Fe3O4 nanoparticles (HPGs/Fe3O4NPs) composites using human adipose-derived mesenchymal stem cells (hAD-MSCs). In this regard, iron oxide nanoparticles (Fe3O4NPs) were assembled on the surface of HPGs at different concentrations. The biocompatibility of the prepared composites was assessed through MTT assay, apoptosis-related gene expression and field emission scanning electron microscopy (FE-SEM) analysis. Compared to the bare HPGs, the HPGs/Fe3O4NPs exhibited a biphasic impact on hAD-MSCs. The composite containing 1% Fe3O4NPs demonstrated no cytotoxicity up to 21 days while higher Fe3O4NPs contents and long-term exposure revealed adverse effects on the hAD-MSCs’ growth. The obtained result was verified by the qRT-PCR and morphological analysis carried out through FE-SEM which suggests that a narrow region below 1% Fe3O4NPs may be the optimum choice for medicinal applications of HPGs/Fe3O4NPs microdevices.

Polydopamine nanospheres coated with bovine serum albumin permit enhanced cell differentiation: fundamental mechanism and practical application for protein coating formation

Protein coating is a strategy for modifying and improving the surface functional properties of nanomaterials. However, the underlying mechanism behind protein coating formation, which is essential for its practical applications, remains largely unknown. Herein, we investigate the fundamental molecular mechanism of protein coating formation. Polydopamine nanospheres (PDANS) coated with bovine serum albumin (BSA) are examined in this study due to their wide biomedical potential. Our results demonstrate that BSAs can flexibly bind to PDANS and maintain their structural dynamicity. Our findings unveil that regular structure formation arises from BSAs lateral interactions via electrostatic forces. Notably, the protein coating modified PDANS surface enhances cell adhesion and proliferation as well as osteogenic differentiation. Such an enhancement is attributed to complementary surface properties provided by the dynamic PDANS-BSA complex and regular structure caused by BSA-BSA interactions in protein coating formation. This study provides a fundamental understanding of the molecular mechanism of protein coating formation, which facilitates the further development of functional protein-coated nanomaterials and guides the bioengineering decision making for biomedical applications, especially in bone tissue engineering.

Nanotechnology for Targeted Detection and Removal of Bacteria: Opportunities and Challenges

The emergence of nanotechnology has created unprecedented hopes for addressing several unmet industrial and clinical issues, including the growing threat so-termed "antibiotic resistance" in medicine. Over the last decade, nanotechnologies have demonstrated promising applications in the identification, discrimination, and removal of a wide range of pathogens. Here, recent insights into the field of bacterial nanotechnology are examined that can substantially improve the fundamental understanding of nanoparticle and bacteria interactions. A wide range of developed nanotechnology-based approaches for bacterial detection and removal together with biofilm eradication are summarized. The challenging effects of nanotechnologies on beneficial bacteria in the human body and environment and the mechanisms of bacterial resistance to nanotherapeutics are also reviewed.

Highly Selective and Sensitive Aggregation-Induced Emission of Fluorescein-Coated Metal Oxide Nanoparticles

We report the synthesis, characterization, and photophysical properties of novel metal oxide nanoparticles (NPs) coated with specially designed fluorescein substituents which are capped with electron-withdrawing groups. The fluorescein-coated nanoparticles were synthesized in excellent yields, and their structures were confirmed using various advanced spectroscopic, instrumental, and surface analysis techniques, revealing the formation of the target functionalized nanoparticles (FNPs) which show superior chemical and thermal stabilities. In addition, the photophysical properties of the FNPs were examined using UV-visible absorption and fluorescence spectroscopy. These latter techniques disclosed aggregation-induced emission (AIE) properties for most of the target FNPs, namely those which are soluble in common organic solvents at selective concentration ranges of water fractions in the solvent mixture.

Lung Surfactant Decreases Biochemical Alterations and Oxidative Stress Induced by a Sub-Toxic Concentration of Carbon Nanoparticles in Alveolar Epithelial and Microglial Cells

Carbon-based nanomaterials are nowadays attracting lots of attention, in particular in the biomedical field, where they find a wide spectrum of applications, including, just to name a few, the drug delivery to specific tumor cells and the improvement of non-invasive imaging methods. Nanoparticles inhaled during breathing accumulate in the lung alveoli, where they interact and are covered with lung surfactants. We recently demonstrated that an apparently non-toxic concentration of engineered carbon nanodiamonds (ECNs) is able to induce oxidative/nitrosative stress, imbalance of energy metabolism, and mitochondrial dysfunction in microglial and alveolar basal epithelial cells. Therefore, the complete understanding of their "real" biosafety, along with their possible combination with other molecules mimicking the in vivo milieu, possibly allowing the modulation of their side effects becomes of utmost importance. Based on the above, the focus of the present work was to investigate whether the cellular alterations induced by an apparently non-toxic concentration of ECNs could be counteracted by their incorporation into a synthetic lung surfactant (DPPC:POPG in 7:3 molar ratio). By using two different cell lines (alveolar (A549) and microglial (BV-2)), we were able to show that the presence of lung surfactant decreased the production of ECNs-induced nitric oxide, total reactive oxygen species, and malondialdehyde, as well as counteracted reduced glutathione depletion (A549 cells only), ameliorated cell energy status (ATP and total pool of nicotinic coenzymes), and improved mitochondrial phosphorylating capacity. Overall, our results on alveolar basal epithelial and microglial cell lines clearly depict the benefits coming from the incorporation of carbon nanoparticles into a lung surfactant (mimicking its in vivo lipid composition), creating the basis for the investigation of this combination in vivo.

Gold nanoparticle-mediated bubbles in cancer nanotechnology

Microbubbles (MBs) have been extensively investigated in the field of biomedicine for the past few decades. Ultrasound and laser are the most frequently used sources of energy to produce MBs. Traditional acoustic methods induce MBs with poor localized areas of action. A high energy level is required to generate MBs through the focused continuous laser, which can be harmful to healthy tissues. As an alternative, plasmonic light-responsive nanoparticles, such as gold nanoparticles (AuNPs), are preferably used with continuous laser to decrease the energy threshold and reduce the bubbles area of action. It is also well-known that the utilization of the pulsed lasers instead of the continuous lasers decreases the needed AuNPs doses as well as laser power threshold. When well-confined bubbles are generated in biological environments, they play their own unique mechanical and optical roles. The collapse of a bubble can mechanically affect its surrounding area. Such a capability can be used for cargo delivery to cancer cells and cell surgery, destruction, and transfection. Moreover, the excellent ability of light scattering makes the bubbles suitable for cancer imaging. This review firstly provides an overview of the fundamental aspects of AuNPs-mediated bubbles and then their emerging applications in the field of cancer nanotechnology will be reviewed. Although the pre-clinical studies on the AuNP-mediated bubbles have shown promising data, it seems that this technique would not be applicable to every kind of cancer. The clinical application of this technique may basically be limited to the good accessible lesions like the superficial, intracavity and intraluminal tumors. The other essential challenges against the clinical translation of AuNP-mediated bubbles are also discussed.

In Vivo Tracking of Extracellular Vesicles by Nuclear Imaging: Advances in Radiolabeling Strategies

Extracellular vesicles (EVs) are naturally secreted vesicles that have attracted a large amount of interest in nanomedicine in recent years due to their innate biocompatibility, high stability, low immunogenicity, and important role in cell-to-cell communication during pathological processes. Their versatile nature holds great potential to improve the treatment of several diseases through their use as imaging biomarkers, therapeutic agents, and drug-delivery vehicles. However, the clinical translation of EV-based approaches requires a better understanding of their in vivo behavior. Several imaging technologies have been used for the non-invasive in vivo tracking of EVs, with a particular emphasis on nuclear imaging due to its high sensitivity, unlimited penetration depth and accurate quantification. In this article, we will review the biological function and inherent characteristics of EVs and provide an overview of molecular imaging modalities used for their in vivo monitoring, with a special focus on nuclear imaging. The advantages of radionuclide-based imaging modalities make them a promising tool to validate the use of EVs in the clinical setting, as they have the potential to characterize in vivo the pharmacokinetics and biological behavior of the vesicles. Furthermore, we will discuss the current methods available for radiolabeling EVs, such as covalent binding, encapsulation or intraluminal labeling and membrane radiolabeling, reporting the advantages and drawbacks of each radiolabeling approach.

Measurement of BAT activity by targeted molecular magnetic resonance imaging

OBJECTIVE

The aim of this study was to measure brown adipose tissue (BAT) activity by targeted peptide (CKGGRAKDC-NH2)-coupled, polyethylene glycol (PEG)-coated ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles with magnetic resonance imaging (MRI).

METHODS

The peptide was conjugated with PEG-coated USPIO to obtain targeted probes. Male C57BL/6 J mice were randomly divided into cold exposing and control group (n = 5 per group). T2*-weighted images were obtained pre- and post-contrast probes. Histological and gene expression analyses were carried out.

RESULTS

T2* relaxation time of BAT in the cold exposing group decreased more significantly compared to the control group. The calculated R2* increased with the reduction of T2* value. The ΔR2* (26.68 s^-1) of BAT in the cold exposing group was significantly higher (P < 0.05) than the control group. Iron particle sediments in BAT of the cold exposing group were revealed more than the control group with Prussian blue staining. The UCP1 expression level was up-regulated after cold activation.

CONCLUSIONS

BAT activity could be measured in vivo by the targeted peptide-coupled, PEG-coated USPIOs with MRI.

Interaction of fibrinogen-magnetic nanoparticle bioconjugates with integrin reconstituted into artificial membranes

Magnetic nanoparticles have a broad spectrum of biomedical applications including cell separation, diagnostics and therapy. One key issue is little explored: how do the engineered nanoparticles interact with blood components after injection? The formation of bioconjugates in the bloodstream and subsequent reactions are potentially toxic due to the ability to induce an immune response. The understanding of the underlying processes is of major relevance to design not only efficient, but also safe nanoparticles for e.g. targeted drug delivery applications. In this study, we report on maghemite nanoparticles functionalized with citrate-, dextran- and polyethylene glycol coatings and their interaction with the clotting protein fibrinogen. Further, we investigate using biophysical tools (e.g. dynamic light scattering, circular dichroism spectroscopy and quartz crystal microbalance) the interaction of the magnetic nanoparticles-fibrinogen bioconjugates with artificial cell membranes as a model system for blood platelets. We found that fibrinogen corona formation provides colloidal stability to maghemite nanoparticles. In addition, bioconjugates of fibrinogen with dextran- and citrate-coated NPs interact with integrin-containing lipid bilayer, especially upon treatment with divalent ions, whereas PEG-coating reveals minor interaction. Our study at the interface of protein-conjugated nanoparticles and artificial cell membranes is essential for engineering safe nanoparticles for drug delivery applications.

Protein corona: Dr. Jekyll and Mr. Hyde of nanomedicine

Nanomedicine is an interdisciplinary field of research, comprising science, engineering, and medicine. Many are the clinical applications of nanomedicine, such as molecular imaging, medical diagnostics, targeted therapy, and image-guided surgery. Despite major advances during the past 20 years, many efforts must be done to understand the complex behavior of nanoparticles (NPs) under physiological conditions, the kinetic and thermodynamic principles, involved in the rational design of NP. Once administrated in physiological environment, NPs interact with biomolecules and they are surrounded by protein corona (PC) or biocorona. PC can trigger an immune response, affecting NPs toxicity and targeting capacity. This review aims to provide a detailed description of biocorona and of parameters that are able to control PC formation and composition. Indeed, the review provides an overview about the role of PC in the modulation of both cytotoxicity and immune response as well as in the control of targeting capacity.

Functionalization of Magnetic Nanoparticles by Folate as Potential MRI Contrast Agent for Breast Cancer Diagnostics

In recent years, the intrinsic magnetic properties of magnetic nanoparticles (MNPs) have made them one of the most promising candidates for magnetic resonance imaging (MRI). This study aims to evaluate the effect of different coating agents (with and without targeting agents) on the magnetic property of MNPs. In detail, iron oxide nanoparticles (IONPs) were prepared by the polyol method. The nanoparticles were then divided into two groups, one of which was coated with silica (SiO2) and hyperbranched polyglycerol (HPG) (SPION@SiO2@HPG); the other was covered by HPG alone (SPION@HPG). In the following section, folic acid (FA), as a targeting agent, was attached on the surface of nanoparticles. Physicochemical properties of nanostructures were characterized using Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and a vibrating sample magnetometer (VSM). TEM results showed that SPION@HPG was monodispersed with the average size of about 20 nm, while SPION@SiO2@HPG had a size of about 25 nm. Moreover, HPG coated nanoparticles had much lower magnetic saturation than the silica coated ones. The MR signal intensity of the nanostructures showed a relation between increasing the nanoparticle concentrations inside the MCF-7 cells and decreasing the signal related to the T2 relaxation time. The comparison of coating showed that SPION@SiO2@HPG (with/without a targeting agent) had significantly higher r2 value in comparison to Fe3O4@HPG. Based on the results of this study, the Fe3O4@SiO2@HPG-FA nanoparticles have shown the best magnetic properties, and can be considered promising contrast agents for magnetic resonance imaging applications.

Nanotoxicology: The Need for a Human Touch?

With the ever-expanding number of manufactured nanomaterials (MNMs) under development there is a vital need for nanotoxicology studies that test the potential for MNMs to cause harm to health. An extensive body of work in cell cultures and animal models is vital to understanding the physicochemical characteristics of MNMs and the biological mechanisms that underlie any detrimental actions to cells and organs. In human subjects, exposure monitoring is combined with measurement of selected health parameters in small panel studies, especially in occupational settings. However, the availability of further in vivo human data would greatly assist the risk assessment of MNMs. Here, the potential for controlled inhalation exposures of MNMs in human subjects is discussed. Controlled exposures to carbon, gold, aluminum, and zinc nanoparticles in humans have already set a precedence to demonstrate the feasibility of this approach. These studies have provided considerable insight into the potential (or not) of nanoparticles to induce inflammation, alter lung function, affect the vasculature, reach the systemic circulation, and accumulate in other organs. The need for further controlled exposures of MNMs in human volunteers - to establish no-effect limits, biological mechanisms, and provide vital data for the risk assessment of MNMs - is advocated.

Magnetic nanocellulose: A potential material for removal of dye from water

In this study, cellulose nanofibers are used as a template to synthesise magnetic nanoparticles with a uniform size distribution. Magnetic nanoparticles are grafted on the surface of nanofibers via in situ hydrolysis of metal precursors at room temperature. Effects of different concentrations of nanofibers on the morphology, the crystallite size of magnetic nanoparticles, and the thermal and magnetic properties of the membrane produced from the cellulose nanofibers decorated with magnetic nanoparticles are examined. The sizes of magnetic nanoparticles produced in this study are below 20 nm, and the crystallite size of the nanoparticles is in the range of 96-130 Å. The flexible magnetic membranes containing a high concentration of magnetic nanoparticles (83-60 wt%) showed superparamagnetic behaviour with very high magnetic properties (67.4-38.5 emu g^-1). The magnetic membrane was then used as an environmentally friendly, low-cost catalyst in a sulphate radical-based advanced oxidation process. The membranes successfully activated peroxymonosulphate (PMS) to remove Rhodamine B (RhB), a common hydrophilic organic dye applied in industry. 94.9 % of the Rhodamine B was degraded in 300 min at room temperature, indicating that the magnetic nanocellulose membrane is highly effective for catalyzing PMS to remove RhB.

Mapping the heterogeneity of protein corona by ex vivo magnetic levitation

In the past decade, we witnessed limited success in the clinical translation of therapeutic nanoparticles (NPs). One of the main reasons for this limited success is our poor understanding of the biological identity of NPs. Herein, we report magnetic levitation (MagLev) as a complementary analytical tool to investigate the homogeneity of the created protein corona (PC) coated NPs through an ex vivo model. Our results demonstrate that the MagLev system not only has the capacity to separate corona coated NPs, but also enables us to study the homogeneity/heterogeneity of the PC. Our findings suggest that current ex vivo isolation methods cause a heterogeneous coverage of PC profiles at the surface of NPs. The MagLev technique, therefore, would be instrumental in identifying and separating fully PC coated NPs which, in turn, enables us to achieve more accurate information on protein corona composition. Ultimately, we believe that the MagLev technique can be used for the fast screening of the homogeneity of corona coated NPs before quantitative analysis of the corona profile/composition, hence definitely improving our fundamental understanding of nano-bio interfaces.

Iron Oxide Nanoparticles for Breast Cancer Theranostics

BACKGROUND

Breast cancer is the second leading cause of death in women worldwide. The extremely fast rate of metastasis and ability to develop resistance mechanism to all the conventional drugs make them very difficult to treat which are the causes of high morbidity and mortality of breast cancer patients. Scientists throughout the world have been focusing on the early detection of breast tumor so that treatment can be started at the very early stage. Moreover, conventional treatment processes such as chemotherapy, radiotherapy, and local surgery suffer from various limitations including toxicity, genetic mutation of normal cells, and spreading of cancer cells to healthy tissues. Therefore, new treatment regimens with minimum toxicity to normal cells need to be urgently developed.

METHODS

Iron oxide nanoparticles have been widely used for targeting hyperthermia and imaging of breast cancer cells. They can be conjugated with drugs, proteins, enzymes, antibodies or nucleotides to deliver them to target organs, tissues or tumors using external magnetic field.

RESULTS

Iron oxide nanoparticles have been successfully used as theranostic agents for breast cancer both in vitro and in vivo. Furthermore, their functionalization with drugs or functional biomolecules enhance their drug delivery efficiency and reduces the systemic toxicity of drugs.

CONCLUSION

This review mainly focuses on the versatile applications of superparamagnetic iron oxide nanoparticles on the diagnosis, treatment, and detecting progress of breast cancer treatment. Their wide application is because of their excellent superparamagnetic, biocompatible and biodegradable properties.

Plasmonic Photothermal Nanoparticles for Biomedical Applications

Recent advances of plasmonic nanoparticles include fascinating developments in the fields of energy, catalyst chemistry, optics, biotechnology, and medicine. The plasmonic photothermal properties of metallic nanoparticles are of enormous interest in biomedical fields because of their strong and tunable optical response and the capability to manipulate the photothermal effect by an external light source. To date, most biomedical applications using photothermal nanoparticles have focused on photothermal therapy; however, to fully realize the potential of these particles for clinical and other applications, the fundamental properties of photothermal nanoparticles need to be better understood and controlled, and the photothermal effect-based diagnosis, treatment, and theranostics should be thoroughly explored. This Progress Report summarizes recent advances in the understanding and applications of plasmonic photothermal nanoparticles, particularly for sensing, imaging, therapy, and drug delivery, and discusses the future directions of these fields.

Maghemite nanoparticles stabilize the protein corona formed with transferrin presenting different iron-saturation levels

Magnetic nanoparticles are ideal candidates for biomedical applications given their potential use in magnetic resonance imaging, magnetic hyperthermia and targeted drug delivery. Understanding protein-nanoparticle interactions in the blood stream is of major importance due to their potential risks, especially immunogenicity (i.e. the ability to induce an immune response). Here, we report on the interaction of superparamagnetic maghemite (γ-Fe2O3) nanoparticles with human blood plasma protein transferrin presenting different iron-saturation levels: partially iron-saturated (i.e. transferrin) and iron-free transferrin (i.e. apotransferrin). The nanoparticle-protein interaction and the protein corona formation were studied using biophysical and chemical approaches based on dynamic light scattering, gel electrophoresis, circular dichroism spectroscopy and differential scanning fluorimetry. We found that iron content governs the protein corona formation and induces a strong effect on the thermal stability of the bound protein. Our results demonstrate a stabilizing effect of the nanoparticles with a change of the unfolding position of approximately 10 °C towards higher temperatures for transferrin. Our study may be relevant for the further development of magnetic nanoparticles as diagnostic and therapeutic tools.

Rational Design of Iron Oxide Binding Peptide Tags

Owing to their extraordinary magnetic properties and low-cost production, iron oxide nanoparticles (IONs) are in the focus of research. In order to better understand interactions of IONs with biomolecules, a tool for the prediction of the propensity of different peptides to interact with IONs is of great value. We present an effective implicit surface model (EISM), which includes several interaction models. Electrostatic interactions, van der Waals interactions, and entropic effects are considered for the theoretical calculations. However, the most important parameter, a surface accessible area force field contribution term, derives directly from experimental results on the interactions of IONs and peptides. Data from binding experiments of ION agglomerates to different peptides immobilized on cellulose membranes have been used to parameterize the model. The work was carried out under defined environmental conditions; hence, effects because of changes, for example structure or solubility by changing the surroundings, are not included. EISM enables researchers to predict the binding of peptides to IONs, which we then verify with further peptide array experiments in an iterative optimization process also presented here. Negatively charged peptides were identified as best binders for IONs in Tris buffer. Furthermore, we investigated the constitution of peptides and how the amount and position of several amino acid side chains affect peptide-binding. The incorporation of glycine leads to higher binding scores compared to the incorporation of cysteine in negatively charged peptides.

Organic Nanotheranostics for Photoacoustic Imaging-Guided Phototherapy

Phototherapies including photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as one of the avant-garde strategies for cancer treatment. Photoacoustic (PA) imaging is a new hybrid imaging modality that shows great promise for real-time in vivo monitoring of biological processes with deep tissue penetration and high spatial resolution. To enhance therapeutic efficacy, reduce side effects and minimize the probability of over-medication, it is necessary to use imaging and diagnostic methods to identify the ideal therapeutic window and track the therapeutic outcome. With this regard, nanotheranostics with the ability to conduct PA imaging and PTT/PDT are emerging. This review summarizes the recent progress of organic nanomaterials including nearinfrared (NIR) dyes and semiconducting polymer nanoparticles (SPNs) in PA imaging guided cancer phototherapy, and also addresses their present challenges and potential in clinical applications.

Biodistribution and targeting properties of iron oxide nanoparticles for treatments of cancer and iron anemia disease

IONP (iron oxide nanoparticles) commercialized for treatments of iron anemia or cancer diseases can be administered at doses exceeding 1 g per patient, indicating their bio-compatibility when they are prepared in the right conditions. Various parameters influence IONP biodistribution such as nanoparticle size, hydrophobicity/hydrophilicity, surface charge, core composition, coating properties, route of administration, quantity administered, and opsonization. IONP biodistribution trends include their capture by the reticuloendothelial system (RES), accumulation in liver and spleen, leading to nanoparticle degradation by macrophages and liver Kupffer cells, possibly followed by excretion in feces. To result in efficient tumor treatment, IONP need to reach the tumor in a sufficiently large quantity, using: (i) passive targeting, i.e. the extravasation of IONP through the blood vessel irrigating the tumor, (ii) molecular targeting achieved by a ligand bound to IONP specifically recognizing a cell receptor, and (iii) magnetic targeting in which a magnetic field gradient guides IONP towards the tumor. As a whole, targeting efficacy is relatively similar for different targeting, yielding a percentage of injected IONP in the tumor of 5.10^-4% to 3%, 0.1% to 7%, and 5.10^-3% to 2.6% for passive, molecular, and magnetic targeting, respectively. For the treatment of iron anemia disease, IONP are captured by the RES, and dissolved into free iron, which is then made available for the organism. For the treatment of cancer, IONP either deliver chemotherapeutic drugs to tumors, produce localized heat under the application of an alternating magnetic field or a laser, or activate in a controlled manner a sono-sensitizer following ultrasound treatment.

Laser irradiation affects the biological identity and cellular uptake of plasmonic nanoparticles

The biological identity of nanoparticles (NPs) is defined by a protein layer formed on their surface, called protein corona (PC), once they meet the biological milieu. Any change in the PC composition may influence the biological fate of NPs. The PC composition is strongly dependent on several parameters including the physicochemical properties of NPs, and biological and environmental factors. As one of the main features of plasmonic NPs is their capacity to induce local heating by laser irradiation, we hypothesized that laser irradiation may change the biological identity of NPs and therefore alter their biological fate. To test this hypothesis, here we investigated the effects of either simultaneous or sequential laser irradiation on the conformations of a few proteins selected from two main categories of plasma proteins (i.e. human serum albumin and human fibrinogen) on the surfaces of gold nanorods (AuNRs). The outcomes revealed a significant role of laser irradiation on conformational changes of fibrinogen compared to albumin. Moreover, the effects of plasmonic heating - at various times - on the achieved corona composition from interactions of AuNRs and human plasma with various concentrations were monitored. Consequently, the cellular uptake of the corona coated AuNRs was measured in two cell types: malignant (MCF-7) and normal (MCF-10A) breast cell lines. The results demonstrated a substantial reduction in the cellular uptake of AuNRs in response to an increase in the laser irradiation time, especially in MCF-10A. Our results may pave the way for a mechanistic understanding of the biological identity of plasmonic NPs which in turn can help their safe and efficient clinical translations.

Molecular origin of AuNPs-induced cytotoxicity and mechanistic study

Gold nanoparticles (AuNPs) with diverse physicochemical properties are reported to affect biological systems differently, but the relationship between the physicochemical properties of AuNPs and their biological effects is not clearly understood. Here, we aimed to elucidate the molecular origins of AuNP-induced cytotoxicity and their mechanisms, focusing on the surface charge and structural properties of modified AuNPs. We prepared a library of well-tailored AuNPs exhibiting various functional groups and surface charges. Through this work, we revealed that the direction or the magnitude of surface charge is not an exclusive factor that determines the cytotoxicity of AuNPs. We, instead, suggested that toxic AuNPs share a common structural characteristics of a hydrophobic moiety neighbouring the positive charge, which can induce lytic interaction with plasma membrane. Mechanistic study showed that the toxic AuNPs interfered with the formation of cytoskeletal structure to slow cell migration, inhibited DNA replication and caused DNA damage via oxidative stress to hinder cell proliferation. Gene expression analysis showed that the toxic AuNPs down-regulated genes associated with cell cycle processes. We discovered structural characteristics that define the cytotoxic AuNPs and suggested the mechanisms of their cytotoxicity. These findings will help us to understand and to predict the biological effects of modified AuNPs based on their physicochemical properties.

Molecular interaction of fibrinogen with zeolite nanoparticles

Fibrinogen is one of the key proteins that participate in the protein corona composition of many types of nanoparticles (NPs), and its conformational changes are crucial for activation of immune systems. Recently, we demonstrated that the fibrinogen highly contributed in the protein corona composition at the surface of zeolite nanoparticles. Therefore, understanding the interaction of fibrinogen with zeolite nanoparticles in more details could shed light of their safe applications in medicine. Thus, we probed the molecular interactions between fibrinogen and zeolite nanoparticles using both experimental and simulation approaches. The results indicated that fibrinogen has a strong and thermodynamically favorable interaction with zeolite nanoparticles in a non-cooperative manner. Additionally, fibrinogen experienced a substantial conformational change in the presence of zeolite nanoparticles through a concentration-dependent manner. Simulation results showed that both E- and D-domain of fibrinogen are bound to the EMT zeolite NPs via strong electrostatic interactions, and undergo structural changes leading to exposing normally buried sequences. D-domain has more contribution in this interaction and the C-terminus of γ chain (γ377-394), located in D-domain, showed the highest level of exposure compared to other sequences/residues.

An investigation into non-covalent functionalization of a single-walled carbon nanotube and a graphene sheet with protein G:A combined experimental and molecular dynamics study

Investigation of non-covalent interaction of hydrophobic surfaces with the protein G (PrG) is necessary due to their frequent utilization in immunosensors and ELISA. It has been confirmed that surfaces, including carbonous-nanostructures (CNS) could orient proteins for a better activation. Herein, PrG interaction with single-walled carbon nanotube (SWCNT) and graphene (Gra) nanostructures was studied by employing experimental and MD simulation techniques. It is confirmed that the PrG could adequately interact with both SWCNT and Gra and therefore fine dispersion for them was achieved in the media. Results indicated that even though SWCNT was loaded with more content of PrG in comparison with the Gra, the adsorption of the PrG on Gra did not induce significant changes in the IgG tendency. Several orientations of the PrG were adopted in the presence of SWCNT or Gra; however, SWCNT could block the PrG-FcR. Moreover, it was confirmed that SWCNT reduced the α-helical structure content in the PrG. Reduction of α-helical structure of the PrG and improper orientation of the PrG-SWCNT could remarkably decrease the PrG tendency to the Fc of the IgG. Importantly, the Gra could appropriately orient the PrG by both exposing the PrG-FcR and also by blocking the fragment of the PrG that had tendency to interact with Fab in IgG.

Preparation, characterization, and evaluation of amino acid modified magnetic nanoparticles: drug delivery and MRI contrast agent applications

This study is a report about the synthesis iron oxide magnetic nanoparticles (IONPs) which modified with positive and negative charged amino acids (AAs). l-Arginine (Arg) and l-aspartic acid (Asp) which have of guanidinium and carboxylic acid groups, respectively, were selected for this study. After loading chrysin in amino acids modified iron oxide magnetic nanoparticles (F@AAs@Chrysin NPs), it was characterized by XRD, TGA, FTIR, VSM, and TEM techniques. Finally, MTT assays on HFF-2 and HEK-293 cell lines were performed for determination of biocompatibility of AA coated IONPs. The results show that, the ζ-potential and average size of F@Arg@chrysin NPs and F@Asp@chrysin NPs were to -3.87, -2.12 mV, 18.75 ± 2.40 (mean ± SD (n = 50)) nm, and 19.86 ± 2.22 (mean ± SD (n = 48)) nm, respectively. Also, the results indicated that these F@AAs@Chrysin NPs were appropriate for delivery of chrysin. Furthermore, the phantom MRI studies showed the IONPs can be used as contrast agent for the revealing of tumor.