Search Results (181)

Lipid nanoparticle (LNP)-based delivery systems are promising tools for advancing RNA-based therapies. However, there are underlying challenges for the oral delivery of LNPs. In this study, we optimized an LNP formulation, which we encapsulated in a pH-sensitive Eudragit^® S 100 (Eu) coating. LNPs were prepared using the DLin-MC3-DMA ionizable lipid, cholesterol, DMG-PEG, and DSPC at a molar ratio of 50:38.5:10:1.5. LNPs were coated with 1% Eu solution via nanoprecipitation using 0.25% acetic acid to get Eu-coated LNPs (Eu-LNPs). Particle characteristics of LNPs were determined by using dynamic light scattering (DLS). Ribogreen and agarose gel retardation assays were used to evaluate nucleic acid entrapment and stability. LNPs and Eu-LNPs were ~120 nm and 4.5 μm in size, respectively. Eu-LNPs decrease to an average size of ~191 ± 22.9 nm at a pH of 8. Phosphate buffer (PB)-treated and untreated Eu-LNPs and uncoated LNPs were transfected in HEK-293 cells. PB-treated Eu-LNPs showed significant transfection capability compared to their non-PB-treated counterparts. Eu-LNPs protected their nucleic acid payloads in the presence of a simulated gastric fluid (SGF) with pepsin and maintained transfection capacity following SGF or simulated intestinal fluid. Hence, Eu coating is a potentially promising approach for the oral administration of LNPs. Full article

Polymer coatings as thin films stand out as a commonly used strategy to modify biosensor surfaces for improving detection performance; however, nonspecific biomolecule interactions and the limited degree of ligand conjugation on the surface have necessitated the development of innovative methods for surface modification. To this end, methacrylated tethered telechelic polyethylene glycol (PEG-diMA) chains of three different molecular weights (2, 6, and 10 kDa) were synthesized herein and used for obtaining thiolated nanoparticles (NPs) upon adding excess amounts of a tetra-thiol crosslinker. Characterized according to their size, surface charge, morphology, and thiol amounts, these nanoparticles were immobilized on gold surfaces that mimicked gold-coated mass sensor platforms. The PEG-based nanoparticles, prepared especially by PEG6K-diMA polymers, were shown to result in the preparation of a monolayer and smooth coating of 80–120 nm thickness. Cysteine-modified NTS(8–13) peptide (RRPYIL) was conjugated to thiolated NP with reversible disulfide bonds and it was demonstrated that its cleavage with a reducing agent such as dithiothreitol (DTT) restores the NP-immobilized gold surface for at least two cycles. Together with its binding studies to NTSR2 antibodies, it was revealed that the peptide-conjugated NP-modified gold surface could be employed as a model for a reusable sensor surface for the detection of biomarkers of same or different types. Full article

The continuous discovery of novel effective antibacterial agents using nano-based materials is of high significance. In this study, we utilized Polymerylated divalent-metal-doped ferrite nanoparticles (PMFe₂O₄ NPs) and studied their antibacterial inhibition effects. Different panels of PVP- and PEG-coated metal-doped MFe₂O₄ (M ≅ Co, Ni, and Zn) were prepared via the Ko-precipitation Hydrolytic Basic (KHB) methodology and thoroughly analyzed using TEM, XRD, FTIR, and VSM. The as-synthesized doped ferrites displayed stable quasi-spherical particles (7–15 nm in size), well-ordered crystalline cubic spinel phases, and high-saturation magnetizations reaching up to 68 emu/g. The antibacterial efficacy of the doped ferrites was then assessed against a Gram-negative E. coli bacterial strain. The results demonstrated that both metal doping and polymer functionalization influence the antimicrobial efficacies and performance of the ferrite NPs. The presence of the PVP polymer along with the divalent metal ions, particularly Co and Ni, resulted in the highest antibacterial inhibition and effective inactivation of the bacterial cells. The antibacterial performance was as follows: PVP-CoFe₂O₄ > PVP-NiFe₂O₄ > PVP-ZnFe₂O₄. Lastly, cell viability assays conducted on human breast fibroblast (HBF) cells confirmed the good safety profiles of the doped ferrites. These interesting results demonstrate the distinctive inhibitory features of the biocompatible metal-doped ferrites in enhancing bacterial killing and highlights their promising potential as effective antimicrobial agents, with possible applications in areas such as water disinfection, biomedical devices, and antimicrobial coatings. Full article

Flavonoids, like Hesperetin, have been shown to be an ACE2 receptor agonists with antioxidant and pro-apoptotic activity and can induce apoptosis in cancer cells. ACE2 receptors are abundant in lung cancer cells. Here, we explored the application of Hesperetin bound to PegPLGA-coated nanoparticles (Hesperetin nanoparticles, HNPs) and anti-CD40 antibody as an aerosol treatment for lung tumor-bearing mice. The Hesperetin nanoparticles (HNPs) were engineered using a nano-formulation microfluidic technique and polymeric nanoparticles. The in vitro studies were performed in human A549 (ATCC) and murine LL/2-Luc2 (ATCC) lung cancer cell lines. A syngeneic orthotopic murine model of lung cancer was generated in wild (+/+) C57/BL6 background mice with luciferase-positive cell line LL/2-Luc2 cells. Lung tumor-bearing mice were treated via aerosol inhalation with HNP, anti-CD40 antibody, or both. Survival was used to analyze the efficacy of the aerosol treatment. The cohorts were also analyzed for body condition score, weight, and liver and kidney function. Analysis of an orthotopic murine lung cancer model demonstrated a differential uptake of the HNPs and anti-CD40 by the cancer cells. A higher survival rate was observed when the combination of aerosol treatment with HNPs was added with the treatment with anti-CD40 (p < 0.001), as compared to anti-CD40 alone (p < 0.01). Moreover, two tumor-bearing mice survived long-term with the combination treatment, and their tumors were diminished. Subsequently, these two mice were shown to be refractory to the development of subcutaneous tumors, indicating systemic resilience to developing new tumors. Using an inhalation-based administration, we successfully established a treatment model of increased therapeutic efficacy with HNPs and anti-CD40 in an orthotopic murine lung cancer model. Our findings open the possibility of improved lung cancer treatment using nanoparticles like flavonoids and immunoadjuvants. Full article

Sputtering onto liquids is rapidly gaining attention for the green and controlled dry synthesis of ultrapure catalysts nanomaterials. In this study, we present a clean and single-step method for the synthesis of gold nanoparticles directly in polyethylene glycol (PEG) liquid using radio frequency (RF) magnetron sputtering and by subsequently transferring them to Nafion ionomer, fabricating a catalyst-coated membrane (CCM), an essential component of the proton exchange membrane water electrolyzer (PEMWE). The samples were systematically characterized at different stages of process development. The innovative transfer process resulted in a monodispersed homogeneous distribution of catalyst particles inside CCM while retaining their nascent nanoscale topography. The chemical analysis confirmed the complete removal of the trapped PEG through the process optimization. The electrochemical catalytic activity of the optimized CCM was verified, and the hydrogen evolution reaction (HER) in acidic media appeared outstanding, a vital step in water electrolysis toward H₂ production. Therefore, this first study highlights the advantages of RF sputtering in liquid for nanoparticle synthesis and its direct application in preparing CCM, paving the way for the development of innovative membrane preparation techniques for water electrolysis. Full article

A self-healing superhydrophobic coating was successfully prepared in the present work. The coating comprised PEG (polyethylene glycol) and Fe₃O₄ nanoparticles modified with stearic acid (SA) via hydrogen bonds, using polyamide resin and epoxy as binders. The chemically damaged surface could restore its original superhydrophobic structure and chemical composition after 4 h at room temperature or 10 min of heating in an oven with a self-healing efficiency of 95.5% and 96.1%, respectively. The hydrogen bonds between SA-OH and Fe₃O₄-OH nanoparticles enabled the repeatable and efficient self-healing properties of the superhydrophobic coating. The coating exhibited remarkable chemical resistance, maintaining superhydrophobicity even after 48 h of immersion in strong acidic and alkaline solutions. Additionally, the prepared fabric showed excellent mechanical stability after 2400 mm of abrasion and 125 cycles of tape peeling with a WCA above 150°. Furthermore, the coated fabric was effective for oil/water separation and anti-icing. With these powerful functions, the proposed superhydrophobic coating holds promising applications in both daily life and industry. Full article

The immobilization of functional nano-blocks by means of electrostatic interactions is a promising technology for creating sensitive layers of (bio)chemical sensors. This is due to the unique ability of electrostatic interactions for directional immobilization and the uniform distribution of charged objects over the surface. This report discusses methods for introducing an electrostatically active buffer layer onto a gold surface and studies its interaction with nanoparticles carrying charges of different signs on their surface. To study the adsorption capacity of the gold surface modified with thiocyanate, silver nanoparticles of 60 nm in size, stabilized by positively charged at pH 5–6 polymer (Ag-NP&BPEI) and negatively charged coatings (Ag-NP&CIT, Ag-NP&PEG, and Ag-NP&PVP), were used as an electrostatic probe. The analysis of SPR and UV-VIS spectroscopy results, electrochemical measurements, and wide-field surface plasmon resonance microscopy imaging indicate that the gold surface modified with thiocyanate behaves as a negatively charged object in processes driven by electrostatic interactions. Full article

The purpose of this research is to design nanocomposite materials for biomedical applications. New conjugates of PEG derivatives of RGD peptides and magnetic nanoparticles, based on Fe₃O₄ (MNPs) with silica coating covalently labelled with fluorescent dye Cyanine5, were obtained. It was shown that a higher loading level of RGD peptides occurred in the case of MNPs with SiO₂/aminopropylsilane coating, synthesised using N-(phosphonomethyl)iminodiacetic acid (PMIDA) as a surfactant. To confirm the structure and chemical purity of the new RGD-PEG conjugate, a number of methods were used, including ¹H NMR, HRMS, and RP-HPLC. The characterisation of MNPs was carried out using the following physical methods: TEM, FTIR, EDX, CHN analysis, DLS, fluorescence spectrometry, vibration magnetometry, and relaxometry. Samples obtained from PMIDA-stabilised MNPs contained a greater amount of the peptide and possessed better hydrodynamic characteristics than samples obtained from non-stabilised MNPs. A comparative study of the MNP cytotoxicity was carried out towards 4T1 and MDA-MB231 cell lines (MTT test), and the possibility of cell labelling was assessed. The cellular uptake was more efficient for nanoconjugates obtained without PMIDA. The data obtained can be used for the design of materials for cell labelling and visualisation. Full article

Within the field of nanomedicine, which is revolutionizing cancer treatment, solid lipid nanoparticles (SLNs) have shown advantages over conventional chemotherapy when tested on cancer cells in preclinical studies. SLNs have proven to be an innovative strategy for the treatment of triple-negative breast cancer cells, providing greater efficiency than existing treatments in various studies. The encapsulation of antineoplastic drugs in SLNs has facilitated a sustained, controlled, and targeted release, which enhances therapeutic efficiency and reduces adverse effects. Moreover, the surface of SLNs can be modified to increase efficiency. For instance, the coating of these particles with polyethylene glycol (PEG) decreases their opsonization, resulting in a longer life in the circulatory system. The creation of positively charged cationic SLNs (cSLNs), achieved by the utilization of surfactants or ionic lipids with positively charged structural groups, increases their affinity for cell membranes and plasma proteins. Hyaluronic acid has been added to SLNs so that the distinct pH of tumor cells would stimulate the release of the drug and/or genetic material. The current review summarizes the recent research on SLNs, focusing on the encapsulation and transport of therapeutic agents with a cytotoxic effect on triple-negative breast cancer. Full article

Background/Objectives: Magnetic Fe₃O₄ nanoparticles (MNPs) are becoming more important every day. We prepared MNPs in a simple one-step reaction by following the solvothermal method, assisted by azide and alkyne functionalized polyethylene glycol (PEG400) polymers, as well as by PEG6000 and the polyol β-cyclodextrin (βCD), which played a crucial role as electrostatic stabilizers, providing polymeric/polyol coatings around the magnetic cores. Methods: The composition, morphology, and magnetic properties of the nanospheres were analyzed using Transmission Electron and Atomic Force Microscopies (TEM, AFM), Nuclear Magnetic Resonance (NMR), X-ray Diffraction Diffractometry (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), Matrix-Assisted Laser Desorption/Ionization (MALDI) and Vibrating Sample Magnetometry (VSM). Results: The obtained nanoparticles (@Fe₃O₄-PEGs and @Fe₃O₄-βCD) showed diameters between 90 and 250 nm, depending on the polymer used and the Fe₃O₄·6H₂O precursor concentration, typically, 0.13 M at 200 °C and 24 h of reaction. MNPs exhibited superparamagnetism with high saturation mass magnetization at room temperature, reaching values of 59.9 emu/g (@Fe₃O₄-PEG6000), and no ferromagnetism. Likewise, they showed temperature elevation after applying an alternating magnetic field (AMF), obtaining Specific Absorption Rate (SAR) values of up to 51.87 ± 2.23 W/g for @Fe₃O₄-PEG6000. Additionally, the formed systems are susceptible to click chemistry, as was demonstrated in the case of the cannabidiol-propargyl derivative (CBD-Pro), which was synthesized and covalently attached to the azide functionalized surface of @Fe₃O₄-PEG400-N₃. Prepared MNPs are highly dispersible in water, PBS, and citrate buffer, remaining in suspension for over 2 weeks, and non-toxic in the T84 human colon cancer cell line, Conclusions: indicating that they are ideal candidates for biomedical applications. Full article

Nanoparticles (NPs) are receiving increasing interest in biomedical applications. However, due to their large surface area, in physiological environments, they tend to interact with plasma proteins, inducing their agglomeration and ultimately resulting in a substantial efficiency decrease in diagnostic and therapeutic applications. To overcome such problems, NPs are typically coated with a layer of hydrophilic and biocompatible polymers, such as PEG chains. However, few examples exist in which this property could be systematically fine-tuned and combined with added properties, such as emission. Herein, we report a novel mussel-inspired catechol-based strategy to obtain biocompatible and multifunctional coatings, using a previously developed polymerization methodology based on the formation of disulfide bridges under mild oxidative conditions. Two families of NPs were selected as the proof of concept: mesoporous silica NPs (MSNPs), due to their stability and known applications, and magnetite NPs (Fe₃O₄ NPs), due to their small size (<10 nm) and magnetic properties. The PEG coating confers biocompatibility on the NPs and can be further functionalized with bioactive molecules, such as glucose units, through the end carboxylic acid moieties. Once we demonstrated the feasibility of our approach to obtaining PEG-based coatings on different families of NPs, we also obtained multifunctional coatings by incorporating fluorescein functionalities. The resulting coatings not only confer biocompatibility and excellent cell internalization, but also allow for the imaging and tracking of NPs within cells. Full article

Gold-based nanoparticles for surface-enhanced Raman scattering (SERS) imaging show great potential for precise tumor detection and photothermal therapy (PTT). However, the metabolizability of gold nanoparticles (Au NPs) raises big concerns. Herein, we designed a core-shelled nanostructure of copper sulfide (CuS)-coated Au NPs with surface pegylation (PEG-Au@CuS NSs). The excreted Au in the gallbladders at 1 h and 4 h in mice injected with PEG-Au@CuS NSs was 8.2- and 19.1-fold of that with the pegylated Au NPs (PEG-AuNPs) of the same Au particle size, respectively. By loading the Raman reporter 3,3′-Diethylthiatricarbocyanine iodide (DTTC) in the core–shell junction of PEG-Au@CuS NSs, the PEG-Au-DTTC@CuS NSs exhibited the Raman signal-to-noise (S/N) ratio of 4.01 after 24 h of intravenous (IV) injection in the mice bearing an orthotopic CT26-Luc colon tumor. By contrast, the DTTC-coated PEG-AuNPs (PEG-Au-DTTC NPs) achieved an S/N ratio of 2.71. Moreover, PEG-Au-DTTC@CuS NSs exhibited an increased photothermal conversion effect compared with PEG-Au-DTTC NPs excited with an 808-nm laser. PEG-Au-DTTC@CuS NSs enabled intraoperative SERS image-guided photothermal therapy for a complete cure of the colon tumor-bearing mice. Our data demonstrated that the PEG-Au-DTTC@CuS NSs are promising intraoperative Raman image-guided theranostic nanoplatform with enhanced hepatobiliary excretion. Full article

Disulfiram (DS) has been shown to have potent anti-cancer activity; however, it is also characterised by its low water solubility and rapid metabolism in vivo. Biodegradable polylactic-co-glycolic acid (PLGA) polymers have been frequently employed in the manufacturing of PLGA nano-carrier drug delivery systems. Thus, to develop DS-loaded PLGA nanoparticles (NPs) capable of overcoming DS’s limitations, two methodologies were used to formulate the NPs: direct nanoprecipitation (DNP) and single emulsion/solvent evaporation (SE), followed by particle size reduction. The DNP method was demonstrated to produce NPs of superior characteristics in terms of size (151.3 nm), PDI (0.083), charge (−37.9 mV), and loading efficiency (65.3%). Consequently, NPs consisting of PLGA and encapsulated DS coated with mPEG_2k-PLGA at adjustable ratios were prepared using the DNP method. Formulations were then characterised, and their stability in horse serum was assessed. Results revealed the PEGylated DS-loaded PLGA nano-carriers to be more efficient; hence, in-vitro studies testing these formulations were subsequently performed using two distinct breast cancer cell lines, showing great potential to significantly enhance cancer therapy. Full article

In this study, spherical or hexagonal NaYF₄:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay. The comet assay was used to determine the oxidative damage of the UCNPs. An in vivo study on mice determined the elimination route and potential accumulation of UCNPs in the body. The results showed that the L- and S-UCNPs were internalized into cells in the lumen of endosomes. The proliferation assay revealed that the L-UCNPs were less toxic than S-UCNPs. The viability of rMSCs incubated with particles decreased in the order S-UCNP@Ale-(PDMA-AEA) > S-UCNP@Ale-PEG > S-UCNPs > S-UCNP@PMVEMA. Similar results were obtained in C6 cells. The oxidative damage measured by the comet assay showed that neat L-UCNPs caused more oxidative damage to rMSCs than all coated UCNPs while no difference was observed in C6 cells. An in vivo study indicated that L-UCNPs were eliminated from the body via the hepatobiliary route; L-UCNP@Ale-PEG particles were almost eliminated from the liver 96 h after intravenous application. Pilot fluorescence imaging confirmed the limited in vivo detection capabilities of the nanoparticles. Full article