Search Results (70)

Acute lymphoblastic leukemia (ALL) represents the most common type of cancer in the pediatric population. The (1;19)(q23;p13) translocation is a primary chromosomal abnormality present in 3–12% of ALL cases. The current study aims to develop a label-free innovative nanodevice for the ultrasensitive diagnosis of the TCF3-PBX1 chimeric oncogene, featuring simplified operation and rapid analysis using minimal sample volumes, which positions it as a superior alternative for clinical diagnostics and early leukemia identification. The biosensor system was engineered on a nanostructured platform composed of polypyrrole (PPy) and a novel chemically functionalized hybrid nanocomposite of platinum nanospheres and titanium dioxide nanoparticles (TiO₂@Pt). Single-stranded oligonucleotide sequences were chemically immobilized on the nanoengineered transducer to enable biospecific detection. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ultraviolet-visible spectroscopy (UV-Vis), and atomic force microscopy (AFM) were used to characterize each stage of the biotechnological device fabrication process. The analytical properties of the sensing tool were explored using recombinant plasmids containing the TCF3-PBX1 oncogenic sequence and clinical specimens from pediatric patients with B-cell ALL. After exposing the molecular monitoring system to the genetic target, significant variations were observed in the voltammetric oxidation current (∆I = 33.08% ± 0.28 to 124.91% ± 17.08) and in the resistance to charge transfer (ΔR_CT = 19.73% ± 0.96 to 83.51% ± 0.84). Data analysis revealed high reproducibility, with a relative standard deviation of 3.66%, a response range from 3.58 aM to 357.67 fM, a detection limit of 19.31 aM, and a limit of quantification of 64.39 aM. Therefore, a novel nanosensor for multiparametric electrochemical screening of the TCF3-PBX1 chimeric oncogene was described for the first time, potentially improving the quality of life for leukemic patients. Full article

Ti/a-C:Cr multilayer films were deposited on 316L stainless steel (SS316L) substrates using medium-frequency alternating current magnetron sputtering, with a single-layer a-C:Cr film also prepared on a titanium substrate. The influence of sputtering pressure on the film’s structure and properties was systematically investigated. Film morphology and microstructure were analyzed via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). At a pressure of 1.4 MPa, the interfacial contact resistance (ICR) of SS316L bipolar plates (BPPs) coated with the films reached as low as 3.30 mΩ·cm², while that of titanium BPPs was 2.90 mΩ·cm². Under simulated proton exchange membrane fuel cell (PEMFC) cathode conditions (70 °C, 0.6 V vs. SCE, 0.5 M H₂SO₄, 5 ppm HF solution), the corrosion current density, Icorr, reached optimal values of 0.69 μA·cm⁻² for SS316L and 0.62 μA·cm⁻² for titanium. These results demonstrate that parameter optimization enables SS316L BPPs to functionally replace titanium counterparts, offering significant cost reductions for metal BPPs and accelerating the commercialization of PEMFC technology. Full article

Recent work has identified biomphalysin (BM) protein from the snail Biomphalaria glabrata as a cytolytic toxin against the Schistosoma mansoni parasite. Ex vivo interactome studies further evidenced BM’s ability to bind bacterial outer membrane proteins, but its specific antibacterial mechanisms and selectivity remain unclear. Accordingly, this study aims to elucidate the interaction between BM and two model bacteria with distinct cell surface architectures: Escherichia coli (Gram−) and Micrococcus luteus (Gram+). Employing a multiscale approach, we used in vivo single-molecule force spectroscopy (SMFS) to probe molecular interactions at the single cell level. Combined with cell aggregation assays, immunoblotting and Atomic Force Microscopy (AFM) imaging, SMFS results evidenced a selective interaction of BM from snail plasma with M. luteus but not E. coli. Exposure of M. luteus to BM compromised cell surface integrity and induced cell aggregation. These effects correlated with a patch-like distribution of BM on M. luteus reminiscent of pore-forming toxins, as revealed by the anti-BM antibody-functionalized AFM tip. Overall, this work highlights the utility of SMFS in dissecting host–pathogen molecular dialogs. It reveals BM’s selective action against M. luteus, potentially via surface clustering, and it shows spatially heterogeneous responses to the toxin within and between individual cells. Full article

This study addresses the development and optothermal analysis of donor–acceptor thin layers, including materials universally used in organic photovoltaic cells. This article presents the impact of temperature on the optical properties and morphology of thin films made from materials commonly used in organic solar cells. This research focused on two donor materials (PTB7 and PTB7th) and two non-fullerene acceptors (Y5 and Y6), individually and in binary combinations with PTB7 and PTB7th. This study employed various techniques, including UV–Vis spectroscopy, ellipsometry, and atomic force microscopy (AFM), to analyze changes in the absorption, refractive index, extinction coefficient, and morphology at temperatures ranging from 30 °C to 120 °C. This research shows reversible changes in thickness and absorption with temperature, but the extent of these changes differs between PTB7 and PTB7th. Y5 shows some reversible changes, while Y6 demonstrates greater instability and more permanent changes at higher temperatures. The enhanced thermal stability of binary mixtures compared to single-component materials was observed. Full article

Its crucial importance to the long-term operation of lithium-ion batteries has made the solid electrolyte interphase (SEI) the subject of intensive research efforts. These investigations are challenging, however, due to the very complex and fragile nature of this layer. With its typical thickness being in the range of some 10 nm and its chemical make-up being highly sensitive to even the smallest amounts of impurities, it becomes clear that artifacts are easily introduced in investigations of the SEI, especially if the measurements are performed ex situ. To help ameliorate these issues, we herein report a combination of non-destructive operando techniques that can be employed simultaneously in the same electrochemical cell to provide a plethora of physical, morphological, and electrochemical data on the macroscopic and microscopic scale. These techniques encompass atomic force microscopy (AFM), electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D), and impedance spectroscopy (EIS). This work focuses on how to combine these techniques in a single electrochemical cell, which is suitable to study SEI formation while avoiding noise, crosstalk, inhomogeneous SEI formation, and other pitfalls. Full article

The removal of surface residues from single-layer graphene (SLG), including poly(methyl methacrylate) (PMMA) polymers and Cl⁻ ions, during the transfer process remains a significant challenge with regard to preserving the intrinsic properties of SLG, with the process often leading to unintended doping and reduced electronic performance capabilities. This study presents a rapid and efficient surface treatment method that relies on an aqueous sodium nitrite (NaNO₂) solution to remove such contaminants effectively. The NaNO₂ solution rinse leverages reactive nitric oxide (NO) species to neutralize ionic contaminants (e.g., Cl⁻) and partially oxidize polymer residues in less than 10 min, thereby facilitating a more thorough final cleaning while preserving the intrinsic properties of graphene. Characterization techniques, including atomic force microscopy (AFM), Kelvin probe force microscopy (KPFM), and X-ray photoelectron spectroscopy (XPS), demonstrated substantial reductions in the levels of surface residues. The treatment restored the work function of the SLG to approximately 4.79 eV, close to that of pristine graphene (~4.5–4.8 eV), compared to the value of nearly 5.09 eV for conventional SLG samples treated with deionized (DI) water. Raman spectroscopy confirmed the reduced doping effects and improved structural integrity of the rinsed SLG. This effective rinsing process enhances the reproducibility and performance of SLG, enabling its integration into advanced electronic devices such as organic light-emitting diodes (OLEDs), photovoltaic (PV) cells, and transistors. Furthermore, the technique is broadly applicable to other two-dimensional (2D) materials, paving the way for next-generation (opto)electronic technologies. Full article

The Ebola virus is a deadly pathogen that has been threatening public health for decades. Recent studies have revealed alternative viral invasion routes where Ebola virus approaches cells via interactions among phosphatidylserine (PS), PS binding ligands such as Gas6, and TAM family receptors such as Axl. In this study, we investigate the interactions among phosphatidylserine on the Ebola viral-like particle (VLP) membrane, human Gas6, and human Axl using atomic force microscope-based single molecule force spectroscopy to compare their binding strength and affinity from a biomechanical perspective. The impact of calcium ions on their interactions is also studied and quantified to provide more details on the calcium-dependent phosphatidylserine-Gas6 binding mechanism. Our results indicate that, in the presence of calcium ions, the binding strengths of VLP-Gas6 and VLP-Gas6-Axl increase but are still weaker than that of Gas6-Axl, and the binding affinity of VLP-Gas6 and VLP-Gas6-Axl is largely improved. The binding strength and affinity of Gas6-Axl basically remain the same, indicating no impact in the presence of calcium ions. Together, our study suggests that, under physiological conditions with calcium present, the Ebola virus can utilize its membrane phosphatidylserine to dock on cell surface via Gas6-Axl bound complex. Full article

The hydroxyapatite and copper-doped hydroxyapatite coatings (Ca_10−xCu_x(PO₄)₆(OH)₂; x_Cu = 0, 0.03; HAp and 3CuHAp) were obtained by the vacuum deposition technique. Then, both coatings were analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and water contact angle techniques. Information regarding the in vitro antibacterial activity and biological evaluation were obtained. The XRD studies confirmed that the obtained thin films consist of a single phase associated with hydroxyapatite (HAp). The obtained 2D and 3D SEM images did not show cracks or other types of surface defects. The FTIR studies’ results proved the presence of vibrational bands characteristic of the hydroxyapatite structure in the studied coating. Moreover, information regarding the HAp and 3CuHAp surface wettability was obtained by water contact angle measurements. The biocompatibility of the HAp and 3CuHAp coatings was evaluated using the HeLa and MG63 cell lines. The cytotoxicity evaluation of the coatings was performed by assessing the cell viability through the MTT assay after incubation with the HAp and 3CuHAp coatings for 24, 48, and 72 h. The results proved that the 3CuHAp coatings exhibited good biocompatible activity for all the tested intervals. The ability of Pseudomonas aeruginosa 27853 ATCC (P. aeruginosa) cells to adhere to and develop on the surface of the HAp and 3CuHAp coatings was investigated using AFM studies. The AFM studies revealed that the 3CuHAp coatings inhibited the formation of P. aeruginosa biofilms. The AFM data indicated that P. aeruginosa’s attachment and development on the 3CuHAp coatings were significantly inhibited within the first 24 h. Both the 2D and 3D topographies showed a rapid decrease in attached bacterial cells over time, with a significant reduction observed after 72 h of exposure. Our studies suggest that 3CuHAp coatings could be suitable candidates for biomedical uses such as the development of new antimicrobial agents. Full article

A new series of chiral 4,5-dihydro-1H-[1,2,4]-triazoline molecules, featuring a β-ᴅ-glucopyranoside appendage, were synthesized via a 1,3-dipolar cycloaddition reaction between various hydrazonyl chlorides and carbohydrate Schiff bases. The isolated enantiopure triazolines (8a–j) were identified through high-resolution mass spectrometry (HRMS) and vibrational spectroscopy. Subsequently, their solution structures were elucidated through NMR spectroscopic techniques. Single-crystal X-ray analysis of derivative 8b provided definitive evidence for the 3-D structure of this compound and revealed important intermolecular forces in the crystal lattice. Moreover, it confirmed the (S)-configuration at the newly generated stereo-center. Selected target compounds were investigated for anti-tumor activity in 60 cancer cell lines, with derivative 8c showing the highest potency, particularly against leukemia. Additionally, substituent-dependent anti-fungal and anti-bacterial behavior was observed. Full article

Scanning force microscopy (SFM) is one of the most widely used techniques in biomaterials research. In addition to imaging the materials of interest, SFM enables the mapping of mechanical properties and biological responses with sub-nanometer resolution and piconewton sensitivity. This review aims to give an overview of using the scanning force microscope (SFM) for investigations on dental materials. In particular, SFM-derived methods such as force–distance curves (scanning force spectroscopy), lateral force spectroscopy, and applications of the FluidFM^® will be presented. In addition to the properties of dental materials, this paper reports the development of the pellicle by the interaction of biopolymers such as proteins and polysaccharides, as well as the interaction of bacteria with dental materials. Full article

Transdermal administration of chemo therapeutics into burn healing may be an effective treatment to reduce toxic side effects and improve patient compliance for burns. As a transdermal delivery system, Camelina lipid droplets (CLDs) have received great attention due to their biocompatibility, high drug payload, and rapid absorption. However, the absorbed-related mechanisms of Camelina lipid droplets have not yet been reported. Thus, this paper not only demonstrated that CLD can accelerate skin burn healing through promoting hFGF2 absorption, but also elucidated the mechanism between the skin tissue and keratinocytes using Franz, HE staining, DSC, FTIR spectroscopy, and atomic force microscopy with the presence of CLD-hFGF2 freeze-dried powder. We found that the cumulative release rate of CLD-hFGF2 freeze-dried powder was significantly higher than that of free hFGF2 freeze-dried powder into the skin. At the same time, CLD can change the structure and content of lipids and keratin to increase the permeability of hFGF2 freeze-dried powder in skin tissue. Unlike the free state of hFGF2, the biophysical properties of single cells, including height and adhesion force, were changed under CLD-hFGF2 freeze-dried powder treatment. Meanwhile, CLD-hFGF2 freeze-dried powder was more easily taken up through keratinocytes without damaging cell integrity, which provided a new viewpoint for understanding the absorption mechanism with the CLD system for cellular physiology characteristics. Overall, our findings demonstrated that CLD could break through the stratum corneum (SC) barrier and elucidated the transport mechanism of lipid droplets in skin tissue, which provides a crucial guideline in drug delivery applications for future engineering. Full article

Chitin is one of the most common polysaccharides and is abundant in the cell walls of fungi and the shells of insects and aquatic organisms as a skeleton. The mechanism of how chitin responds to pH is essential to the precise control of brewing and the design of smart chitin materials. However, this molecular mechanism remains a mystery. Results from single-molecule studies, including single-molecule force spectroscopy (SMFS), AFM imaging, and molecular dynamic (MD) simulations, have shown that the mechanical and conformational behaviors of chitin molecules show surprising pH responsiveness. This can be compared with how, in natural aqueous solutions, chitin tends to form a more relaxed spreading conformation and show considerable elasticity under low stretching forces in acidic conditions. However, its molecular chain collapses into a rigid globule in alkaline solutions. The results show that the chain state of chitin can be regulated by the proportions of inter- and intramolecular H-bonds, which are determined via the number of water bridges on the chain under different pH values. This basic study may be helpful for understanding the cellular activities of fungi under pH stress and the design of chitin-based drug carriers. Full article

This work presents the effect of monovalent (Ag⁺, Na⁺), divalent (Ca²⁺, Cd²⁺), and trivalent (La³⁺) metal ion doping and annealing temperature (500, 800, and 1200 °C) on the structure, morphology, and magnetic properties of MnFe₂O₄/SiO₂ ceramic nanocomposites synthesized via sol–gel method. Fourier-transform infrared spectroscopy confirms the embedding of undoped and doped MnFe₂O₄ nanoparticles in the SiO₂ matrix at all annealing temperatures. In all cases, the X-ray diffraction (XRD) confirms the formation of MnFe₂O₄. In the case of undoped, di-, and trivalent metal-ion-doped gels annealed at 1200 °C, three crystalline phases (cristobalite, quartz, and tridymite) belonging to the SiO₂ matrix are observed. Doping with mono- and trivalent ions enhances the nanocomposite’s structure by forming single-phase MnFe₂O₄ at low annealing temperatures (500 and 800 °C), while doping with divalent ions and high annealing temperature (1200 °C) results in additional crystalline phases. Atomic force microscopy (AFM) reveals spherical ferrite particles coated by an amorphous layer. The AFM images showed spherical particles formed due to the thermal treatment. The structural parameters calculated by XRD (crystallite size, crystallinity, lattice constant, unit cell volume, hopping length, density, and porosity) and AFM (particle size, powder surface area, and thickness of coating layer), as well as the magnetic parameters (saturation magnetization, remanent magnetization, coercivity, and anisotropy constant), are contingent on the doping ion and annealing temperature. By doping, the saturation magnetization and magnetocrystalline anisotropy decrease for gels annealed at 800 °C, but increase for gels annealed at 1200 °C, while the remanent magnetization and coercivity decrease by doping at both annealing temperatures (800 and 1200 °C). Full article

Influenza A viruses (IAVs) initiate infection via binding of the viral hemagglutinin (HA) to sialylated glycans on host cells. HA’s receptor specificity towards individual glycans is well studied and clearly critical for virus infection, but the contribution of the highly heterogeneous and complex glycocalyx to virus–cell adhesion remains elusive. Here, we use two complementary methods, glycan arrays and single-virus force spectroscopy (SVFS), to compare influenza virus receptor specificity with virus binding to live cells. Unexpectedly, we found that HA’s receptor binding preference does not necessarily reflect virus–cell specificity. We propose SVFS as a tool to elucidate the cell binding preference of IAVs, thereby including the complex environment of sialylated receptors within the plasma membrane of living cells. Full article

Aberrant expression of glycans, i.e., oligosaccharide moiety covalently attached to proteins or lipids, is characteristic of various cancers, including urothelial ones. The binding of lectins to glycans is classified as molecular recognition, which makes lectins a strong tool for understanding their role in developing diseases. Here, we present a quantitative approach to tracing glycan–lectin interactions in cells, from the initial to the steady phase of adhesion. The cell adhesion was measured between urothelial cell lines (non-malignant HCV29 and carcinoma HT1376 and T24 cells) and lectin-coated surfaces. Depending on the timescale, single-cell force spectroscopy, and adhesion assays conducted in static and flow conditions were applied. The obtained results reveal that the adhesion of urothelial cells to two specific lectins, i.e., phytohemagglutinin-L and wheat germ agglutinin, was specific and selective. Thus, these lectins can be applied to selectively capture, identify, and differentiate between cancer types in a label-free manner. These results open up the possibility of designing lectin-based biosensors for diagnostic or prognostic purposes and developing strategies for drug delivery that could target cancer-associated glycans. Full article