Spinel ZnCr2O4 nanorods synthesized by facile sol-gel auto combustion method with biomedical properties

In this study, spinel zinc chromite nanorods (ZnCr₂O₄ NRs) were successfully manipulated by a simple sol-gel auto combustion process employing urea as fuel. The sample was only required to sinter at 500 °C for 2 h to obtain the single crystalline phase. The phase formation, crystallinity, and surface topography of synthesized ZnCr₂O₄ NRs were explored by X-ray diffraction (XRD), UV-Vis reflectance spectroscopy (UVDRS), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) spectroscopy, and vibrating sample magnetometry (VSM). XRD analysis confirms the formation of spinel ZnCr₂O₄ NRs. The FTIR spectrum displays the two vibrational peaks of Cr-O, and Zn-O at 489 and 615 cm^-1, correspondingly. These vibrational bonds were correlated with ZnCr₂O₄ and revealed the production of cubic spinel ZnCr₂O₄ NRs. FESEM indicates the presence of hexagonal-rod-shaped particles. EDX spectrum demonstrates the elemental composition of the ZnCr₂O₄ NRs and confirms the primary peak of Zn, Cr, and O. The obtained ZnCr₂O₄ NRs exhibit an antiferromagnetic behavior. The bandgap energy of ZnCr₂O₄ NRs was ascertained and was shown to be 3.45 eV. Furthermore, the antifungal and antibacterial effect of ZnCr₂O₄ NRs was examined against pathogenic strains by disc diffusion technique. Besides these, the antimalarial activity of ZnCr₂O₄ NRs was studied against Plasmodium falciparum. Thus, the as-synthesized ZnCr₂O₄ NRs showed significant antibacterial, antifungal and antimalarial activity and may be helpful for research opening a novel horizon in nanomedicine. Graphical abstract.

An Update on Graphene Oxide: Applications and Toxicity

Graphene oxide (GO) has attracted much attention in the past few years because of its interesting and promising electrical, thermal, mechanical, and structural properties. These properties can be altered, as GO can be readily functionalized. Brodie synthesized the GO in 1859 by reacting graphite with KClO3 in the presence of fuming HNO3; the reaction took 3-4 days to complete at 333 K. Since then, various schemes have been developed to reduce the reaction time, increase the yield, and minimize the release of toxic byproducts (NO2 and N2O4). The modified Hummers method has been widely accepted to produce GO in bulk. Due to its versatile characteristics, GO has a wide range of applications in different fields like tissue engineering, photocatalysis, catalysis, and biomedical applications. Its porous structure is considered appropriate for tissue and organ regeneration. Various branches of tissue engineering are being extensively explored, such as bone, neural, dentistry, cartilage, and skin tissue engineering. The band gap of GO can be easily tuned, and therefore it has a wide range of photocatalytic applications as well: the degradation of organic contaminants, hydrogen generation, and CO2 reduction, etc. GO could be a potential nanocarrier in drug delivery systems, gene delivery, biological sensing, and antibacterial nanocomposites due to its large surface area and high density, as it is highly functionalized with oxygen-containing functional groups. GO or its composites are found to be toxic to various biological species and as also discussed in this review. It has been observed that superoxide dismutase (SOD) and reactive oxygen species (ROS) levels gradually increase over a period after GO is introduced in the biological systems. Hence, GO at specific concentrations is toxic for various species like earthworms, Chironomus riparius, Zebrafish, etc.

Strategy for Avoiding Protein Corona Inhibition of Targeted Drug Delivery by Linking Recombinant Affibody Scaffold to Magnetosomes

Purpose

Nanoparticles (NPs) decorated with functional ligands are promising candidates for cancer diagnosis and treatment. However, numerous studies have shown that chemically coupled targeting moieties on NPs lose their targeting capability in the biological milieu because they are shielded or covered by a “protein corona”. Herein, we construct a functional magnetosome that recognizes and targets cancer cells even in the presence of protein corona.

Methods

Magnetosomes (BMPs) were extracted from magnetotactic bacteria, M. gryphiswaldense (MSR-1), and decorated with trastuzumab (TZ) via affibody (RA) and glutaraldehyde (GA). The engineered BMPs are referred to as BMP-RA-TZ and BMP-GA-TZ. Their capacities to combine HER2 were detected by ELISA, the quantity of plasma corona proteins was analyzed using LC-MS. The efficiencies of targeting SK-BR-3 were demonstrated by confocal laser scanning microscopy and flow cytometry.

Results

Both engineered BMPs contain up to ~0.2 mg TZ per mg of BMP, while the quantity of HER2 binding to BMP-RA-TZ is three times higher than that binding to BMP-GA-TZ. After incubation with normal human plasma or IgG-supplemented plasma, GA-TZ-containing BMPs have larger hydrated radii and more surface proteins in comparison with RA-TZ-containing BMPs. The TZ-containing BMPs all can be targeted to and internalized in the HER2-overexpressing breast cancer cell line SK-BR-3; however, their targeting efficiencies vary considerably: 50–75% for RA-TZ-containing BMPs and 9–19% for GA-TZ-containing BMPs. BMPs were incubated with plasma (100%) and cancer cells to simulate human in vivo environment. In this milieu, BMP-RA-TZ uptake efficiency of SK-BR-3 reaches nearly 80% (slightly lower than for direct interaction with BMP-RA-TZ), whereas the BMP-GA-TZ uptake efficiency is <17%.

Conclusion

Application of the RA scaffold promotes and orients the arrangement of targeting ligands and reduces the shielding effect of corona proteins. This strategy improves the targeting capability and drug delivery of NP in a simulated in vivo milieu.

Photodynamic effect of light emitting diodes on E. coli and human skin cells induced by a graphene-based ternary composite

In this paper, the photodynamic effect of a ternary nanocomposite (TiO₂-Ag/graphene) on Escherichia coli bacteria and two human cell lines: A375 (melanoma) and HaCaT (keratinocyte) after exposure to different wavelength domains (blue, green or red-Light Emitting Diode, LED) was analyzed. The results obtained through bioassays were correlated with the morphological, structural and spectral data obtained through FT-IR, XPS and UV-Vis spectroscopy, powder X-Ray diffractometry (XRD) and STEM/EDX techniques, leading to conclusions that showed different photodynamic activation mechanisms and effects on bacteria and human cells, depending on the wavelength. The nanocomposite proved a therapeutic potential for blue light-activated antibacterial treatment and revealed a keratinocyte cytotoxic effect under blue and green LEDs. The red light-nanocomposite duo gave a metabolic boost to normal keratinocytes and induced stasis to melanoma cells. The light and nanocomposite combination could be a potential therapy for bacterial keratosis or for skin tumors.

Fundamentals to Apply Magnetic Nanoparticles for Hyperthermia Therapy

The activation of magnetic nanoparticles in hyperthermia treatment by an external alternating magnetic field is a promising technique for targeted cancer therapy. The external alternating magnetic field generates heat in the tumor area, which is utilized to kill cancerous cells. Depending on the tumor type and site to be targeted, various types of magnetic nanoparticles, with variable coating materials of different shape and surface charge, have been developed. The tunable physical and chemical properties of magnetic nanoparticles enhance their heating efficiency. Moreover, heating efficiency is directly related with the product values of the applied magnetic field and frequency. Protein corona formation is another important parameter affecting the heating efficiency of MNPs in magnetic hyperthermia. This review provides the basics of magnetic hyperthermia, mechanisms of heat losses, thermal doses for hyperthermia therapy, and strategies to improve heating efficiency. The purpose of this review is to build a bridge between the synthesis/coating of magnetic nanoparticles and their practical application in magnetic hyperthermia.

Analysis of the Human Plasma Proteome Using Multi-Nanoparticle Protein Corona for Detection of Alzheimer's Disease

As the population affected by Alzheimer's disease (AD) grows, so does the need for a noninvasive and accurate diagnostic tool. Current research reveals that AD pathogenesis begins as early as decades before clinical symptoms. The unique properties of nanoparticles (NPs) may be exploited to develop noninvasive diagnostics for early detection of AD. After exposure of NPs to biological fluids, the NP surface is altered by an unbiased but selective and reproducible adsorption of biomolecules commonly referred to as the biomolecular corona or protein corona (PC). The discovery that the plasma proteome may be differentially altered during health and disease leads to the concept of disease-specific PCs. Herein, the disease-specific PCs formed around NPs in a multi-NPs platform are employed to successfully identify subtle changes in plasma protein patterns and detect AD (>92% specificity and ≈100% sensitivity). Similar discrimination power is achieved using banked plasma samples from a cohort of patients several years prior to their diagnosis with AD. With the nanoplatform's analytic ability to analyze pathological proteomic changes into a disease-specific identifier, this promising, noninvasive technology with implications for early detection and intervention could benefit not only patients with AD but other diseases as well.

Mg(1-x)CuxFe2O4 superparamagnetic nanoparticles as nano-radiosensitizer agents in radiotherapy of MCF-7 human breast cancer cells

Magnesium-doped copper spinel ferrite superparamagnetic nanoparticles (Mg_(1-x)Cu_xFe₂O₄ SPMNPs, 0.2 ≤ x ≤ 0.8) were successfully synthesized by a hydrothermal method. The cytotoxicity effects and cell viability of MCF-7 on human breast cancer cells pre and post exposure to the Mg_1-xCu_xFe₂O₄ SPMNPs at different concentrations of 0.1, 1, 10 and 100 μg ml^-1 under radiotherapy were studied by MTT (3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay. Here, x-ray diffraction, scanning electron microscopy, atomic force microscopy, UV-visible spectrophotometry, Fourier transform infrared spectroscopy and vibrating-sample magnetometry were evaluated for the crystal structure, morphology, optical and magnetic property of the Mg_(1-x)Cu_xFe₂O₄ SPMNPs. The results showed that the Mg_(1-x)Cu_xFe₂O₄ SPMNPs all at x values had no significant cytotoxicity at concentrations of 0.1,1 and 10 μg ml^-1, but were enhanced by increasing of Cu content. Furthermore, cell destruction of MCF-7 human breast cancer cells post exposure to Mg_(1-x)Cu_xFe₂O₄ SPMNPs under x-ray irradiation was enhanced by increasing the Cu content and concentration. Superparamagnetic properties of the Mg_(1-x)Cu_xFe₂O₄ SPMNPs cause their localization and elimination, by only an external magnetic field. In conclusion, the Mg_(1-x)Cu_xFe₂O₄ SPMNPs with optimum values of x = 0.2 (10 μg ml^-1) and x = 0.6 (1 μg ml^-1) can be considered as a nano-radiosensitizer because of the synergistic treatment effect without cytotoxicity on the MCF-7 cells.

Supramolecular Insights into Domino Effects of Ag@ZnO-Induced Oxidative Stress in Melanoma Cancer Cells

Recent studies suggest that cancer cell death accompanied by organelle dysfunction might be a promising approach for cancer therapy. The Golgi apparatus has a key role in cell function and may initiate signaling pathways to mitigate stress and, if irreparable, start apoptosis. It has been shown that Golgi disassembly and fragmentation under oxidative stress act as indicators for stress-mediated cell death pathways through cell cycle arrest in the G2/M phase. The present study shows that UV-induced reactive oxygen species (ROS) generation by Ag@ZnO nanoparticles (NPs) transform the Golgi structures from compressed perinuclear ribbons into detached vesicle-like structures distributed in the entire cytoplasm of melanoma cells. This study also demonstrates that Ag@ZnO NP-induced Golgi fragmentation cooccurs with G2 block of cell cycle progression, preventing cells from entering the mitosis phase. Additionally, the increased intracellular ROS production triggered by Ag@ZnO NPs upon UV exposure promoted autophagy. Taken together, Ag@ZnO NPs induce stress-related Golgi fragmentation and autophagy, finally leading to melanoma cell apoptosis. Intracellular oxidative stress generated by Ag@ZnO NPs upon UV irradiation may thus represent a targeted approach to induce cancer cell death through organelle destruction in melanoma cells, while fibroblast cells remained largely unaffected.

A health concern regarding the protein corona, aggregation and disaggregation

Nanoparticle (NP)-protein complexes exhibit the "correct identity" of NP in biological media. Therefore, protein-NP interactions should be closely explored to understand and modulate the nature of NPs in medical implementations. This review focuses mainly on the physicochemical parameters such as dimension, surface chemistry, morphology of NPs, and influence of pH on the formation of protein corona and conformational changes of adsorbed proteins by different kinds of techniques. Also, the impact of protein corona on the colloidal stability of NPs is discussed. Uncontrolled protein attachment on NPs may bring unwanted impacts such as protein denaturation and aggregation. In contrast, controlled protein adsorption by optimal concentration, size, pH, and surface modification of NPs may result in potential implementation of NPs as therapeutic agents especially for disaggregation of amyloid fibrils. Also, the effect of NPs-protein corona on reducing the cytotoxicity and clinical implications such as drug delivery, cancer therapy, imaging and diagnosis will be discussed. Validated correlative physicochemical parameters for NP-protein corona formation frequently derived from protein corona fingerprints of NPs which are more valid than the parameters obtained only on the base of NP features. This review may provide useful information regarding the potency as well as the adverse effects of NPs to predict their behavior in vivo.

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.

Sensing of Alzheimer's Disease and Multiple Sclerosis Using Nano-Bio Interfaces

It is well understood that patients with different diseases may have a variety of specific proteins (e.g., type, amount, and configuration) in their plasmas. When nanoparticles (NPs) are exposed to these plasmas, the resulting coronas may incorporate some of the disease-specific proteins. Using gold (Au) NPs with different surface properties and corona composition, we have developed a technology for the discrimination and detection of two neurodegenerative diseases, Alzheimer's disease (AD) and multiple sclerosis (MS). Applying a variety of techniques, including UV-visible spectra, colorimetric response analyses and liquid chromatography-tandem mass spectrometry, we found the corona-NP complexes, obtained from different human serums, had distinct protein composition, including some specific proteins that are known as AD and MS biomarkers. The colorimetric responses, analyzed by chemometrics and statistical methods, demonstrate promising capabilities of the technology to unambiguously identify and discriminate AD and MS. The developed colorimetric technology might enable a simple, inexpensive and rapid detection/discrimination of neurodegenerative diseases.

Superparamagnetic iron oxide nanocargoes for combined cancer thermotherapy and MRI applications

Nanoparticle-based cancer diagnosis-therapy integrative systems (cancer theranostics) represent an emerging approach in oncology. To address this issue in the present work iron oxide (γ-Fe2O3-maghemite) nanoparticles (IONPs) were encapsulated within the matrix of (bis(p-sulfonatophenyl)phenylphosphine)-methoxypolyethylene glycol-thiol (mPEG) polymer vesicles using a two-step process for active chemotherapeutic cargo loading in cancer theranostics. This formation method gives simple access to highly reactive surface groups present on IONPs together with good control over the vesicle size (50-100 nm). The simultaneous loading of a chemotherapeutic drug cargo (doxorubicin) and its in vitro release in cancer cells was achieved. The feasibility of controlled drug release under different pH conditions was demonstrated in the case of encapsulated doxorubicin molecules, showing the viability of the concept of stimulated drug delivery for magneto-chemotherapy. These polymer-magnetic nanocargoes (PMNCs) exhibit enhanced contrast properties that open potential applications for magnetic resonance imaging. These self-assembled magnetic polymersomes can be used as efficient multifunctional nanocarriers for combined therapy and imaging.

Functional Graphene Nanomaterials Based Architectures: Biointeractions, Fabrications, and Emerging Biological Applications

Functional graphene nanomaterials (FGNs) are fast emerging materials with extremely unique physical and chemical properties and physiological ability to interfere and/or interact with bioorganisms; as a result, FGNs present manifold possibilities for diverse biological applications. Beyond their use in drug/gene delivery, phototherapy, and bioimaging, recent studies have revealed that FGNs can significantly promote interfacial biointeractions, in particular, with proteins, mammalian cells/stem cells, and microbials. FGNs can adsorb and concentrate nutrition factors including proteins from physiological media. This accelerates the formation of extracellular matrix, which eventually promotes cell colonization by providing a more beneficial microenvironment for cell adhesion and growth. Furthermore, FGNs can also interact with cocultured cells by physical or chemical stimulation, which significantly mediate their cellular signaling and biological performance. In this review, we elucidate FGNs-bioorganism interactions and summarize recent advancements on designing FGN-based two-dimensional and three-dimensional architectures as multifunctional biological platforms. We have also discussed the representative biological applications regarding these FGN-based bioactive architectures. Furthermore, the future perspectives and emerging challenges will also be highlighted. Due to the lack of comprehensive reviews in this emerging field, this review may catch great interest and inspire many new opportunities across a broad range of disciplines.

Zeolite Nanoparticles Inhibit Aβ-Fibrinogen Interaction and Formation of a Consequent Abnormal Structural Clot

EMT-type zeolite nanoparticles (EMT NPs) with particle size of 10-20 nm and external surface area of 200 m²/g have shown high selective affinity toward plasma protein (fibrinogen). Besides, the EMT NPs have demonstrated no adverse effect on blood coagulation hemostasis. Therefore, it was envisioned that the EMT NPs could inhibit possible β-amyloid (Aβ)-fibrinogen interactions that result in the formation of structurally abnormal clots, which are resistant to lysis, in cerebral vessels of patients with Alzheimer disease (AD). To evaluate this hypothesis, the clot formation and degradation of Aβ-fibrinogen in the presence and absence of the EMT zeolite NPs were assessed. The results clearly showed that the delay in clot dissolution was significantly reduced in the presence of zeolite NPs. By formation of protein corona, the EMT NPs showed a negligible reduction in their inhibitory strength. Docking of small molecules (Aβ-fibrinogen) introduced a novel potential inhibitory candidate. The zeolite NPs showed similar inhibitory effects on binding of fibrinogen to both Aβ(25-35) and/or Aβ(1-42). This indicates that the inhibitory strength of these NPs is independent of Aβ sequence, and it is suggested that the zeolite NPs adsorb fibrinogen and specifically obstruct their Aβ binding sites. Therefore, the zeolite NPs can be the safe and effective inhibitors in preventing Aβ-fibrinogen interaction and consequent cognitive damage.

Multimodal Superparamagnetic Nanoparticles with Unusually Enhanced Specific Absorption Rate for Synergetic Cancer Therapeutics and Magnetic Resonance Imaging

Superparamagnetic nanoparticles (SPMNPs) used for magnetic resonance imaging (MRI) and magnetic fluid hyperthermia (MFH) cancer therapy frequently face trade off between a high magnetization saturation and their good colloidal stability, high specific absorption rate (SAR), and most importantly biological compatibility. This necessitates the development of new nanomaterials, as MFH and MRI are considered to be one of the most promising combined noninvasive treatments. In the present study, we investigated polyethylene glycol (PEG) functionalized La1-xSrxMnO3 (LSMO) SPMNPs for efficient cancer hyperthermia therapy and MRI application. The superparamagnetic nanomaterial revealed excellent colloidal stability and biocompatibility. A high SAR of 390 W/g was observed due to higher colloidal stability leading to an increased Brownian and Neel's spin relaxation. Cell viability of PEG capped nanoparticles is up to 80% on different cell lines tested rigorously using different methods. PEG coating provided excellent hemocompatibility to human red blood cells as PEG functionalized SPMNPs reduced hemolysis efficiently compared to its uncoated counterpart. Magnetic fluid hyperthermia of SPMNPs resulted in cancer cell death up to 80%. Additionally, improved MRI characteristics were also observed for the PEG capped La1-xSrxMnO3 formulation in aqueous medium compared to the bare LSMO. Taken together, PEG capped SPMNPs can be useful for diagnosis, efficient magnetic fluid hyperthermia, and multimodal cancer treatment as the amphiphilicity of PEG can easily be utilized to encapsulate hydrophobic drugs.

Understanding the nanoparticle-protein corona complexes using computational and experimental methods

Nanoparticles (NP) have capability to adsorb proteins from biological fluids and form protein layer, which is called protein corona. As the cell sees corona coated NPs, the protein corona can dictate biological response to NPs. The composition of protein corona is varied by physicochemical properties of NPs including size, shape, surface chemistry. Processing of protein adsorption is dynamic phenomena; to that end, a protein may desorb or leave a surface vacancy that is rapidly filled by another protein and cause changes in the corona composition mainly by the Vroman effect. In this review, we discuss the interaction between NP and proteins and the available techniques for identification of NP-bound proteins. Also we review current developed computational methods for understanding the NP-protein complex interactions.

Photothermal and photodynamic therapy reagents based on rGO–C6H4–COOH

A photothermal and photodynamic therapy reagent based on rGO–C₆H₄–COOH was developed, which could effectively induce cancer cell apoptosis.

Graphene–polyglycerol–curcumin hybrid as a near-infrared (NIR) laser stimuli-responsive system for chemo-photothermal cancer therapy

The aim of this study is to develop a nano graphene–polyglycerol–curcumin hybrid capable of simultaneous co-delivery of chemotherapeutic drug and cytotoxic heat to cancer cells by near infrared (NIR) laser irradiation.

Personalized disease-specific protein corona influences the therapeutic impact of graphene oxide

The hard corona, the protein shell that is strongly attached to the surface of nano-objects in biological fluids, is recognized as the first layer that interacts with biological objects (e.g., cells and tissues). The decoration of the hard corona (i.e., the type, amount, and conformation of the attached proteins) can define the biological fate of the nanomaterial. Recent developments have revealed that corona decoration strongly depends on the type of disease in human patients from which the plasma is obtained as a protein source for corona formation (referred to as the 'personalized protein corona'). In this study, we demonstrate that graphene oxide (GO) sheets can trigger different biological responses in the presence of coronas obtained from various types of diseases. GO sheets were incubated with plasma from human subjects with different diseases/conditions, including hypofibrinogenemia, blood cancer, thalassemia major, thalassemia minor, rheumatism, fauvism, hypercholesterolemia, diabetes, and pregnancy. Identical sheets coated with varying protein corona decorations exhibited significantly different cellular toxicity, apoptosis, and uptake, reactive oxygen species production, lipid peroxidation and nitrogen oxide levels. The results of this report will help researchers design efficient and safe, patient-specific nano biomaterials in a disease type-specific manner for clinical and biological applications.

Cancer cell extinction through a magnetic fluid hyperthermia treatment produced by superparamagnetic Co–Zn ferrite nanoparticles

TEG mediated synthesis of CZF MNPs for cancer cell extinction by using magnetic fluid hyperthermia therapy.