Search Results (107)

The development of highly sensitive approaches for detecting tumor cells in biological samples remains a critical challenge in laboratory and clinical oncology. In this study, we investigated the structural and magnetic properties of iron oxide nanoparticles incorporated into cellulose microspheres of two size ranges (~100 and ~700 μm) and evaluated their potential for targeted tumor cell isolation. In the smaller microspheres, magnetite-based magnetic nanoparticles (MNPs) were synthesized in situ via co-precipitation, whereas pre-synthesized MNPs were embedded into the larger microspheres. The geometrical characteristics of the resulting magnetic cellulose microspheres (MSCMNs) were assessed by confocal microscopy. Transmission electron microscopy and X-ray diffraction analyses revealed an average magnetic core size of approximately 17 nm. Magnetic properties of the MNPs within MSCMNs were characterized using a highly sensitive nonlinear magnetic response technique, and their dynamic parameters were derived using a formalism based on the stochastic Hilbert–Landau–Lifshitz equation. To evaluate their applicability in cancer diagnostics and treatment monitoring, the MSCMNs were functionalized with a TKD peptide that selectively binds membrane-associated Hsp70 (mHsp70), yielding TKD@MSCMNs. Magnetic separation enabled the isolation of tumor cells from biological fluids. The specificity of TKD-mediated binding was confirmed using Flamma648-labeled Hsp70 and compared with control alloferone-conjugated microspheres (All@MSCMNs). The ability of TKD@MSCMNs to selectively extract mHsp70-positive tumor cells was validated using C6 glioma cells and mHsp70-negative FetMSCs controls. Following co-incubation, the extraction efficiency for C6 cells was 28 ± 14%, significantly higher than that for FetMSC (7 ± 7%, p < 0.05). These findings highlight the potential of TKD-functionalized magnetic cellulose microspheres as a sensitive platform for tumor cell detection and isolation. Full article

We introduce a BiHom-type skew-symmetric bracket on general linear Lie algebra $GL\left(V\right)$ built from two commuting inner automorphisms $\alpha =A{d}_{\psi }$ and $\beta =A{d}_{\varphi }$, with $\psi ,\varphi \in GL\left(V\right)$ and integers $i,j$. We prove that $(GL\left(V\right),{[·,·]}_{(\psi ,\varphi )}^{(i,j)},\alpha ,\beta )$ is a BiHom–Lie algebra, and we study the Lax equation obtained by replacing the commutator in the finite nonperiodic Toda lattice by this bracket. For the symmetric choice $\varphi =\psi$ with $(i,j)=(0,0)$, the deformed flow is equivariant under conjugation and becomes gauge-equivalent, via $\tilde{L}={\psi }^{-1}L\psi$, to a Toda-type Lax equation with a conjugated triangular projection. In particular, scalar deformations amount to a constant rescaling of time. On embedded $2\times 2$ blocks, we derive explicit trigonometric and hyperbolic formulae that make symmetry constraints (e.g., tracelessness) transparent. In the asymmetric hyperbolic case, we exhibit a trace obstruction showing that the right-hand side is generically not a commutator, which amounts to symmetry breaking of the isospectral property. We further extend the construction to the weakly coupled Toda lattice with an indefinite metric and provide explicit $2\times 2$ solutions via an inverse-scattering calculation, clarifying and correcting certain formulas in the literature. The classical Toda dynamics are recovered at special parameter values. Full article

This article reviews the research progress of BN-doped polycyclic aromatic hydrocarbons in the field of optoelectronics in recent years. Polycyclic aromatic hydrocarbons and their derivatives have attracted widespread attention in the field of organic optoelectronic materials due to their unique optical and electronic properties and thus are widely used in various fields such as organic light-emitting diodes (OLEDs), field-effect transistors (OFETs), and organic solar cells (OSCs). By introducing boron–nitrogen (BN) units to replace carbon–carbon (C-C) units in the framework of polycyclic aromatic hydrocarbons, the electronic structure and spatial configuration of conjugated molecules can be effectively regulated, thereby optimizing their optoelectronic properties. This article first outlines the structural characteristics of BN-doped polycyclic aromatic hydrocarbons, then explores their synthesis methods and properties, and provides a detailed overview of their applications in the field of optoelectronics. BN-doped polycyclic aromatic hydrocarbons have shown great potential for applications in both optical and electrical fields. Finally, this review points out that although the application of BN-embedded polycyclic aromatic hydrocarbons in optoelectronic devices is still in its early stages, facing difficulties in synthesis and insufficient stability, the rational design of BN to replace polycyclic aromatic hydrocarbons is expected to bring new opportunities for organic electronics and advance the development of this field. Full article

This study employs molecular orbital (MO) analysis, density of states (DOS) analysis, and advanced techniques such as charge density difference (CDD), transition density matrix (TDM), transition electric dipole moment density (TEDM), and transition magnetic dipole moment density (TMDM) to systematically investigate the electronic structure characteristics of Fc-[8]CPP and Fc-[11]CPP. Using density functional theory (DFT) and time-dependent DFT (TD-DFT), the π-electron delocalization properties and optical behaviors of these molecules were analyzed. Furthermore, their responses to external electromagnetic fields were explored through electronic circular dichroism (ECD) and Raman spectroscopy, comparing chiral optical responses and electron–vibration coupling effects to elucidate their photophysical properties. The results reveal that the HOMO-LUMO energy gaps of Fc-[8]CPP and Fc-[11]CPP are 5.81 eV and 5.95 eV, respectively, with a slight increase as ring size grows; Fc-[8]CPP exhibits a stronger chiral response, while Fc-[11]CPP shows reduced chirality due to enhanced symmetry. Finally, TD-DFT calculations demonstrate that their optical absorption is dominated by localized excitations with partial charge transfer contributions. These findings provide a theoretical foundation for designing conjugated macrocyclic materials with superior optoelectronic performance. Full article

Background/Objectives: Glioblastoma (GBM) remains the most aggressive primary brain tumor, characterized by high malignancy, recurrence rate, and dismal prognosis, thereby demanding innovative therapeutic strategies. In this study, we report a novel in situ targeting inclusion complex hydrogel hybrid system (DOX/RGD-CD@Gel) that integrates doxorubicin (DOX) with RGD-conjugated cyclodextrin (RGD-CD) and a thermosensitive hydrogel for enhanced GBM therapy. Methods: The DOX/RGD-CD@Gel system was prepared by conjugating doxorubicin (DOX) with RGD-modified cyclodextrin (RGD-CD) and embedding it into a thermosensitive hydrogel. The drug delivery and antitumor efficacy of this system were evaluated in vitro and in vivo. Results: In vitro and in vivo evaluations demonstrated that DOX/RGD-CD@Gel significantly enhanced cytotoxicity compared to free DOX or DOX/CD formulations. The targeted delivery system effectively promoted apoptosis and inhibited cell proliferation and metastasis in GBM cells. Moreover, the hydrogel-based system exhibited prolonged drug retention in the brain, as evidenced by its temperature- and pH-responsive release characteristics. In a GBM mouse model, DOX/RGD-CD@Gel significantly suppressed tumor growth and improved survival rates. Conclusions: This study presents a paradigm of integrating a targeted inclusion complex with a thermosensitive hydrogel, offering a safe and efficacious strategy for localized GBM therapy with potential translational value. Full article

Salmonella is a rapidly spreading and widespread zoonotic infectious disease that poses a serious threat to the safety of both poultry and human lives. Therefore, the timely detection of Salmonella in foods and animals has become an urgent need for food safety. This work describes the construction of an aptamer-based sensor for Salmonella detection, using Fe₃O₄ magnetic beads and Ag@Au core–shell nanoparticles-embedded 4-mercaptobenzoic acid (4MBA). Leveraging the high affinity between biotin and streptavidin, aptamers were conjugated to Fe₃O₄ magnetic beads. These beads were then combined with Ag@4MBA@Au nanoparticles functionalized with complementary aptamers through hydrogen bonding and π-π stacking interactions, yielding a SERS-based aptamer sensor with optimized Raman signals from 4MBA. When target bacteria are present, aptamer-conjugated magnetic beads exhibit preferential binding to the bacteria, leading to a decrease in the surface-enhanced Raman scattering (SERS) signal. And it was used for the detection of five different serotypes of Salmonella, respectively, and the results showed that the aptamer sensor exhibited a good linear relationship between the concentration range of 10²–10⁸ CFU/mL and LOD is 35.51 CFU/mL. The SERS aptasensor was utilized for the detection of spiked authentic samples with recoveries between 94.0 and 100.4%, which proved the usability of the method and helped to achieve food safety detection. Full article

A composite-coated inclusion is embedded in a matrix, where the conductivity (permittivity) of the phases is assumed to be complex-valued. The purpose of this paper is to demonstrate that a non-zero flux can arise under specific conditions related to the conductivities of the components in the absence of external sources. These conditions are unattainable with conventional positive conductivities but can be satisfied when the conductivities are negative or complex—a scenario achievable in the context of metamaterials. The problem is formulated as a spectral boundary value problem for the Laplace equation, featuring a linear conjugation condition defined on a smooth curve L. This curve divides the plane ${\mathbb{R}}^2$ into two regions, $D^{+}$ and $D^{-}\ni \infty$. The spectral parameter appears in the boundary condition, drawing parallels with the Steklov eigenvalue problem. The case of a circular annulus is analyzed using the method of functional equations. The complete set of eigenvalues is derived by applying the classical theory of self-adjoint operators in Hilbert space. Full article

This study seeks to develop and implement a non-enzymatic fluorescent labeling for immunoassay and immunochromatographic assay (ICAs) targeting SARS-CoV-2, to meet the extensive interest and need for effective COVID-19 diagnosis. In this manuscript, we delineate the development, synthesis, and evaluation of a novel quinone polymer zinc hybrid nanoarchitecture, referred to as polymerized alizarin red–inorganic hybrid nanoarchitecture (PARIHN), which integrates an antibody for direct use in fluorescent immunoassays, offering enhanced sensitivity, reduced costs, and improved environmental sustainability. The designed nanoarchitecture can enhance the sensitivity of the immunoassay and enable rapid results without the complexities associated with enzymes, such as their low stability and high cost. At first, a chitosan–alizarin polymer was synthesized utilizing quinone–chitosan conjugation chemistry (QCCC). Then, the chitosan–alizarin polymer was embedded with the detection antibody using zinc ion, forming PARIHN, which was proven to be a stable label with the ability to enhance the assay stability and sensitivity of the immunoassay. PARIHN can react with phenylboronic acid (PBA) or boric acid through its alizarin content to produce fluorescence signals with an LOD of 15.9 and 2.6 pm for PBA and boric acid, respectively, which is the first use of a boric acid derivative in signal generation in the immunoassay. Furthermore, PARIHN demonstrated high practicality in detecting SARS-CoV-2 nucleoprotein in fluorescence (PBA and boric acid) systems with an LOD of 0.76 and 10.85 pm, respectively. Furthermore, owing to the high brightness of our PARIHN fluorogenic reaction, our labeling approach was extended to immunochromatographic assays for SARS-CoV-2 with high sensitivity down to 9.45 pg/mL. Full article

Here, we demonstrate through AFM imaging and CD spectroscopy that the binding of silver ions (Ag⁺) to poly(dGdC), a double-stranded (ds) DNA composed of two identical repeating strands, at a stoichiometry of one Ag⁺ per GC base pair induces a one-base shift of one strand relative to the other. This results in a ds nucleic acid-Ag⁺ conjugate consisting of alternating CC and GG base pairs coordinated by silver ions. The proposed organization of the conjugate is supported by the results of our Quantum Mechanical (QM) and Molecular Mechanics (MMs) calculations. The reduction of Ag⁺ ions followed by the partial oxidation of silver atoms yields a highly fluorescent conjugate emitting at 720 nm. This fluorescent behavior in conjugates of long, repetitive ds DNA (thousands of base pairs) with silver has never been demonstrated before. We propose that the poly(dGdC)–Ag conjugate functions as a dynamic system, comprising various small clusters embedded within the DNA and interacting with one another through energy transfer. This hypothesis is supported by the results of our QM and MMs calculations. Additionally, these DNA–silver conjugates, comprising silver nanoclusters, may possess conductive properties, making them potential candidates for use as nanowires in nanodevices and nanosensors. Full article

Ionic porous polymers have been widely utilized efficiently to anchor various metal atoms for the preparation of metal-embedded heteroatom-doped porous carbon composites as the active materials for electrocatalytic applications. However, the rational design of the heteroatom and metal elements in HPC-based composites remains a significant challenge, due to the tendency of the aggregation of metal nanoparticles during pyrolysis. In this study, a nitrogen (N)- and sulfur (S)-enriched ionic covalent organic framework (iCOF) incorporating viologen and thieno[3,4-b] thiophene (TbT) was constructed via Zincke-type polycondensation. The synthesized iCOF possesses a crystalline porous structure with a pore size of 3.05 nm, a low optical band gap of 1.88 eV, and superior ionic conductivity of 10^−2.672 S cm⁻¹ at 333 K, confirming the ionic and conjugated nature of our novel iCOF. By applying the iCOF as the precursor, a ruthenium and ruthenium(IV) oxide (Ru/RuO₂) nanoparticle-embedded N/S-co-doped porous carbon composite (NSPC-Ru) was prepared by using a two-step sequence of anion-exchange and pyrolysis processes. In the electrochemical nitrogen reduction reaction (eNRR) application, the NSPC-Ru achieves an impressive NH₃ yield rate of 32.0 μg h⁻¹ mg⁻¹ and a Faradaic efficiency of 13.2% at −0.34 V vs. RHE. Thus, this innovative approach proposes a new route for the design of iCOF-derived metal-embedded porous carbon composites for enhanced NRR performance. Full article

Background/Objectives: The ability of bacteria to form biofilms makes them more tolerant to traditional antibiotics. Given the lack of new antibiotic development, drug repurposing offers a strategy for discovering new treatments. Auranofin (AF), a gold-based compound indicated for the treatment of rheumatoid arthritis, shows promising antibacterial activity. This study investigates the antimicrobial and antibiofilm activity of AF and its two derivatives in which the thiosugar ligand is replaced by acetylcysteine (AF-AcCys) or naproxen (AF-Napx), against Staphylococcus aureus and Staphylococcus epidermidis. Methods: AF was conjugated by transmetalation with either naproxen or acetylcysteine. Assessments of their stability in DMSO/H₂O and lipophilicity expressed as the LogP were performed. The antimicrobial activity of AF and its analogues were investigated by broth microdilution assay to determine the minimum inhibitory concentration (MIC) and versus biofilm to obtain the minimum bactericidal biofilm concentration (MBBC) and minimum biofilm eradication concentration (MBEC). Results: AF derivatives were found to be stable in a DMSO/H₂O mixture for 48 h. AF-Napx showed a LogP = 1.25 ± 0.22, close to AF, while AF-AcCys had a LogP = −0.95. MIC values of S. aureus and S. epidermidis were ranging from 2 µM to 0.25 µM, and ≤0.12 µM, respectively. Both AF and AF-Napx maintained efficacy against biofilm-embedded S. aureus and S. epidermidis at non-cytotoxic concentrations, with AF-Napx demonstrating lower MBBC values for S. epidermidis. Conclusions: AF, and especially its naproxen conjugate, holds potential as a therapeutic agent for treating biofilm-associated infections caused by S. aureus and S. epidermidis, particularly in device-related infections where both infection and inflammation are present. Full article

Lateral flow immunoassays (LFIAs) are widely used for their low cost, simplicity, and rapid results; however, enhancing their reliability requires the meticulous selection of ligands and nanoparticles (NPs). SiO₂@QD@SiO₂ (QD²) nanoparticles, which consist of quantum dots (QDs) embedded in a silica (SiO₂) core and surrounded by an outer SiO₂ shell, exhibit significantly higher fluorescence intensity (FI) compared to single QDs. In this study, we prepared QD²@PEG@Aptamer, an aptamer conjugated with QD² using succinimidyl-[(N-maleimidopropionamido)-hexaethyleneglycol]ester, which is 130 times brighter than single QDs, for detecting carbohydrate antigen (CA) 19-9 through LFIA. For LFIA optimization, we determined the optimal conditions as a 1.0:2.0 × 10⁻² ratio of polyethylene glycol (PEG) to aptamer by adjusting the amounts of PEG and aptamer, phosphate-buffered saline containing 0.5% Tween^® 20 as a developing solution, and 0.15 μg NPs by setting the NP weight during development. Under these conditions, QD²@PEG@Aptamer selectively detected CA19-9, achieving a detection limit of 1.74 × 10⁻² mg·mL⁻¹. Moreover, FI remained stable for 10 days after detection. These results highlight the potential of QD² and aptamer conjugation technology as a reliable and versatile sensing platform for various diagnostic applications. Full article

This study reports the development of highly conductive and stretchable fibrous membranes based on PVDF/PAN conjugate electrospinning with embedded silver nanoparticles (AgNPs) for wearable sensing applications. The fabrication process integrated conjugate electrospinning of PVDF/PAN, selective dissolution of polyvinylpyrrolidone (PVP) to create porous networks, and uniform AgNP incorporation via adsorption-reduction. Systematic optimization revealed that 10 wt.% PVP content and 1.2 mol/L AgNO₃ concentration yielded membranes with superior electrical conductivity (874.93 S/m) and mechanical strength (2.34 MPa). The membranes demonstrated excellent strain sensing performance with a gauge factor of 12.64 within 0–30% strain and location-specific sensing capabilities: moderate movements at wrist (ΔR/R₀: 98.90–287.25%), elbow (124.65–300.24%), and fingers (177.01–483.20%) generated stable signals, while knee articulation exhibited higher sensitivity (459.60–1316.48%) but significant signal fluctuations. These results demonstrate the potential of the developed conductive porous PVDF/PAN composite fibrous membranes for applications in wearable sensors, flexible electronics, and human-machine interfaces, particularly in scenarios requiring moderate-range motion detection with high reliability and stability. The findings suggest promising opportunities for developing next-generation wearable sensing devices through the optimization of conjugate electrospun fibrous membranes. Full article

The objective of this study was to compare the properties of core–shell nanoparticles with a PLGA core and shells composed of different types of polymers, focusing on their structural integrity. The core PLGA nanoparticles were prepared either through a high-pressure homogenization–solvent evaporation technique or nanoprecipitation, using poloxamer 188 (P188), a copolymer of divinyl ether with maleic anhydride (DIVEMA), and human serum albumin (HSA) as the shell-forming polymers. The shells were formed through adsorption, interfacial embedding, or conjugation. For dual fluorescent labeling, the core- and shell-forming polymers were conjugated with Cyanine5, Cyanine3, and rhodamine B. The nanoparticles had negative zeta potentials and sizes ranging from 100 to 250 nm (measured using DLS) depending on the shell structure and preparation technique. The core–shell structure was confirmed using TEM and fluorescence spectroscopy, with the appearance of FRET phenomena due to the donor–acceptor properties of the labels. All of the shells enhanced the cellular uptake of the nanoparticles in Gl261 murine glioma cells. The integrity of the core–shell structures upon their incubation with the cells was evidenced by intracellular colocalization of the fluorescent labels according to the Manders’ colocalization coefficients. This comprehensive approach may be useful for the selection of the optimal preparation method even at the early stages of the core–shell nanoparticle development. Full article

Over 20 years have passed since siRNA was brought to the public’s attention. Silencing genes with siRNA has been used for various purposes, from creating pest-resistant plants to treating human diseases. In the last six years, several siRNA therapies have been approved by the FDA, which solely target disease-inducing proteins in the liver. The extrahepatic utility of systemically delivered siRNA has been primarily limited to preclinical studies. While siRNA targeting the liver comprises relatively simple ligand-siRNA conjugates, siRNA treating extrahepatic diseases such as cancer often requires complex carriers. The complexity of these extrahepatic carriers of siRNA reduces the likelihood of their widespread clinical use. In the current report, we initially demonstrated that a linear histidine–lysine (HK) carrier of siRNA, injected intravenously, effectively silenced luciferase expressed by MDA-MB-435 tumors in a mouse model. This non-pegylated linear peptide carrier was easily synthesized compared to the complex cRGD-conjugated pegylated branched peptides our group used previously. Notably, the tumor-targeting component, KHHK, was embedded within the peptide, eliminating the need to conjugate the ligand to the carrier. Moreover, brief bath sonication significantly improved the in vitro and in vivo silencing of these HK siRNA polyplexes. Several other linear peptides containing the -KHHK- sequence were then screened with some carriers of siRNA, silencing 80% of the tumor luciferase marker. Additionally, silencing by these HK siRNA polyplexes was confirmed in a second tumor model. Not only was luciferase activity reduced, but these siRNA polyplexes also reduced the Raf-1 oncogene in the MDA-MB-231 xenografts. These simple-to-synthesize, effective, linear HK peptides are promising siRNA carriers for clinical use. Full article