- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Vibrational spectroscopic imaging and live cell video microscopy for studying differentiation of primary human alveolar epithelial cells
摘要： Alveolar type II(ATII) cells in the peripheral human lung spontaneously differentiate towards alveolar type I(ATI) cells, thus enabling air-blood barrier formation. Here, linear Raman and coherent anti-Stokes Raman scattering (CARS) microscopy are applied to study cell differentiation of freshly isolated ATII cells. The Raman spectra can successfully be correlated to gradual morphological and molecular changes during cell differentiation. Alveolar surfactant rich vesicles in ATII cells are identified based on phospholipid vibrations, while ATI-like cells are characterized by the absence of vesicular structures. Complementary, CARS microscopy allows for 3D visualization of lipid vesicles within ATII cells and their secretion, while hyperspectral CARS enables the distinction between cellular proteins and lipids according to their vibrational signatures. This study paves the path for further label-free investigations of lung cells and the role of the pulmonary surfactant, thus also providing a basis for rational development of future lung therapeutics.
关键词： confocal laser scanning microscopy,confocal Raman microscopy,pneumocyte type II differentiation,CARS microscopy,cell imaging
更新于2025-09-23 15:23:52
-
An Expandable Mechanopharmaceutical Device (3): a Versatile Raman Spectral Cytometry Approach to Study the Drug Cargo Capacity of Individual Macrophages
摘要： Purpose To improve cytometric phenotyping abilities and better understand cell populations with high interindividual variability, a novel Raman-based microanalysis was developed to characterize macrophages on the basis of chemical composition, specifically to measure and characterize intracellular drug distribution and phase separation in relation to endogenous cellular biomolecules. Methods The microanalysis was developed for the commercially-available WiTec alpha300R confocal Raman microscope. Alveolar macrophages were isolated and incubated in the presence of pharmaceutical compounds nilotinib, chloroquine, or etravirine. A Raman data processing algorithm was specifically developed to acquire the Raman signals emitted from single-cells and calculate the signal contributions from each of the major molecular components present in cell samples. Results Our methodology enabled analysis of the most abundant biochemicals present in typical eukaryotic cells and clearly identified Bfoamy^ lipid-laden macrophages throughout cell populations, indicating feasibility for cellular lipid content analysis in the context of different diseases. Single-cell imaging revealed differences in intracellular distribution behavior for each drug; nilotinib underwent phase separation and self-aggregation while chloroquine and etravirine accumulated primarily via lipid partitioning. Conclusions This methodology establishes a versatile cytometric analysis of drug cargo loading in macrophages requiring small numbers of cells with foreseeable applications in toxicology, disease pathology, and drug discovery.
关键词： lipid-laden foamy macrophages,intracellular drug bioaccumulation,single-cell chemical imaging,confocal Raman microscopy,pulmonary alveolar macrophages
更新于2025-09-23 15:19:57
-
Functionalized graphene transistor for ultrasensitive detection of carbon quantum dots
摘要： Ubiquitous carbon nanomaterials have great potential for emerging technologies, but they also pose a threat to human health at the end of their lifecycle, especially when they are introduced into waste or ground waters. Graphene field-effect transistors (GFET) and real time in situ confocal Raman microscopy (CRM) were employed to detect a submonolayer of carbon quantum dots (CQDs) in water. An effective GFET channel was formed on exfoliated and chemical vapor deposited (CVD) graphene. The adsorption of CQDs was monitored by measuring conductance changes in GFETs. The graphene channel was functionalized with (3-aminopropyl) triethoxysilane (APTES), which allowed for easy observation of a shift in the charge neutrality point (CNP) when the graphene channel was exposed to CQDs. The affinity of the CQD’s carboxyl terminal groups to the aminofunctionalized channel enabled a highly sensitive CQD detection based on changes in the GFET conductivity. The adsorption of the CQDs induced a positive shift of the CNP with a limit of detection at concentrations of 239 ppm and 62 ppm for the exfoliated and CVD graphene, respectively. A supporting study of graphene functionalization and CQD adsorption was performed by real time in situ CRM, ellipsometry, and ex situ X-ray photoelectron spectroscopy.
关键词： graphene field-effect transistors,carbon quantum dots,confocal Raman microscopy,chemical vapor deposited graphene,aminofunctionalized channel
更新于2025-09-12 10:27:22
-
Investigation of thermal stability of 2D and 3D CoAl2O4 particles in core-shell nanostructures by Raman spectroscopy
摘要： We are studying the formation of a nanostructured spinel CoAl2O4 layer on α-Al2O3 giving rise to a core-shell composite. In the final product, two mechanisms of CoAl2O4 crystallization onto a α-Al2O3 microparticle surface are observed, depending on the dispersion grade of Co3O4: a 3D nanostructure from the arrangement of Co3O4 agglomerated nanoparticles; 2D nanoparticles from the diffusion mechanism of isolated Co3O4 nanoparticles. As a consequence, two different crystallization pathways may occur during the thermal treatment. In order to understand the formation mechanisms a Raman Confocal Study is performed. The features of the Raman spectra of the samples depend strongly on the morphology of the nanoparticles located in the shell of the microparticle. Average spectra of the samples show a variation in the Raman shift between the different samples. The differences between 3D or 2D structures is associated with the transmission of phonons among the nanoparticles. The high absorbance of the cobalt species could mask the Raman shift displacement by local heating, so both the temperature and the laser source power are considered in the Raman study. The evolution of the Raman spectra with applied temperature indicates a decoupling of the Raman modes. This fact is more relevant for the 3D aggregates in which nanoparticles produced a larger scattering of phonons and a higher sensitivity to temperature variation. These results clearly indicate that extrinsic parameters such as the size of the crystals and their aggregation state affects their Raman properties.
关键词： Confocal Raman microscopy,Dry dispersion,Core-shell,CoAl2O4 spinel
更新于2025-09-10 09:29:36
-
Evaluating the efficiency of γ-valerolactone/water/acid system on Eucalyptus pretreatment by confocal Raman microscopy and enzymatic hydrolysis for bioethanol production
摘要： g-Valerolactone (GVL)/water/acid has been developed as a mild solvent system to pretreat biomass. In this study, Eucalyptus was pretreated with 80/20 GVL/water with the addition of H2SO4 (20e100 mM) at 120 (cid:1)C for 30e60 min, and the resulting cellulose-enriched residual fractions were further enzymatically hydrolyzed. Results showed that the pretreatment of Eucalyptus with GVL/water/acid system led to a significant decrease in the contents of lignin and hemicelluloses, and the enzymatic hydrolysis efficiency of the pretreated sample was significantly improved. Meanwhile, the removal of lignin and hemicelluloses from the cell walls during the pretreatment process was monitored by the confocal Raman spectra. Under the optimum conditions (50 mM H2SO4 and 60 min), the delignification rate was up to 90.7% and the cellulose content in the residue was reached to 86.1%. The high cellulose content led to a high cellulose conversion rate and the glucose yield was 6.1-fold higher than that of the raw material without pretreatment. In short, this process provided an efficient approach to remove hemicelluloses and lignin from Eucalyptus to enhance enzymatic hydrolysis for bioethanol production.
关键词： Pretreatment,g-Valerolactone,Confocal Raman microscopy,Enzymatic hydrolysis
更新于2025-09-09 09:28:46
-
Single layer graphene for estimation of axial spatial resolution in confocal Raman microscopy depth profiling
摘要： Single layer graphene (SLG), with its angstrom-scale thickness and strong Raman scattering cross section, was adapted for measurement of the axial (Z-direction) probe beam profile in confocal Raman microscopy depth-profiling experiments. SLG adsorbed to a glass microscope coverslip (SLG/SiO2) served as a platform for estimation of axial spatial resolution. Profiles were measured by stepping the confocal probe volume through the SLG/SiO2 interface while measuring Raman scattering from the sample. Using a high numerical aperture (1.4 NA) oil immersion objective, axial profiles were derived from the graphene 2D vibrational mode and fit to a Lorentzian instrument response function (IRF). Subsequently, the Z-direction spatial resolution in depth-profiling studies of polymer interfaces was estimated through convolution of the Lorentzian IRF with a step function representing the ideal junction separating the phases of interest. In the study of a bipolar polymer membrane, confocal Raman depth profiles of the AEM/CEM (anion exchange membrane / cation exchange membrane) interface show the transition region is broader than the limiting response and are consistent with roughness at the boundary on the order of a few micrometers. Using ClO4- as a Raman active mobile ion probe, application of self-modeling curve resolution (SMCR) to spectral datasets within a profile showed ClO4- ions track the spatial distribution of the AEM phase. Finally, in measurements on a liquid-solid interface formed between 1-octanol and a polydimethylsiloxane (PDMS) membrane, the IRF derived from fitting the experimental profile was slightly narrower than those obtained from profiling SLG, indicating the potential to use polymer-liquid interfaces formed from widely available materials and reagents for estimation of axial spatial resolution in confocal Raman depth-profiling.
关键词： Axial spatial resolution,Polymer interfaces,Confocal Raman microscopy,Single layer graphene,Bipolar membrane,Depth profiling
更新于2025-09-04 15:30:14