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MALDI MS Imaging at Acquisition Rates Exceeding 100 Pixels per Second
摘要： The practicality of matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) applied to molecular imaging of biological tissues is limited by the analysis speed. Typically, a relatively low speed of stop-and-go micromotion of XY stages is considered as a factor substantially reducing the rate with which fresh sample material can be supplied to the laser spot. The sample scan rate in our laboratory-built high-throughput imaging TOF mass spectrometer was significantly improved through the use of a galvanometer-based optical scanner performing fast laser spot repositioning on a target plate. The optical system incorporated into the ion source of our MALDI TOF mass spectrometer allowed focusing the laser beam via a modified grid into a 10-μm round spot. This permitted the acquisition of high-resolution MS images with a well-defined pixel size at acquisition rates exceeding 100 pixel/s. The influence of selected parameters on the total MS imaging time is discussed. The new scanning technique was employed to display the distribution of an antitumor agent in 3D colorectal adenocarcinoma cell aggregates; a single MS image comprising 100 × 100 pixels with 10-μm lateral resolution was recorded in approximately 70 s.
关键词： MSI,TOF,Mass spectrometry imaging,High throughput,Laser beam scanning,Colorectal adenocarcinoma,3D cell aggregates,Spheroids,Grid ion source,MALDI
更新于2025-09-23 15:21:01
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Non-Invasive Quantification of the Growth of Cancer Cell Colonies by a Portable Optical Coherence Tomography
摘要： Investigation of tumor development is essential in cancer research. In the laboratory, living cell culture is a standard bio-technology for studying cellular response under tested conditions to predict in vivo cellular response. In particular, the colony formation assay has become a standard experiment for characterizing the tumor development in vitro. However, quantification of the growth of cell colonies under a microscope is difficult because they are suspended in a three-dimensional environment. Thus, optical coherence tomography (OCT) imaging was develop in this study to monitor the growth of cell colonies. Cancer cell line of Huh 7 was used and the cells were applied on a layer of agarose hydrogel, i.e., a non-adherent surface. Then, cell colonies were gradually formed on the surface. The OCT technique was used to scan the cell colonies every day to obtain quantitative data for describing their growth. The results revealed the average volume increased with time due to the formation of cell colonies day-by-day. Additionally, the distribution of cell colony volume was analyzed to show the detailed information of the growth of the cell colonies. In summary, the OCT provides a non-invasive quantification technique for monitoring the growth of the cell colonies. From the OCT images, objective and precise information is obtained for higher prediction of the in vivo tumor development.
关键词： cell culture,cell colonies,tumor spheroids,optical coherence tomography
更新于2025-09-19 17:15:36
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Matrix Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI MSI) for Monitoring of Drug Response in Primary Cancer Spheroids
摘要： Matrix Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI MSI) for Monitoring of Drug Response in Primary Cancer Spheroids. Malignant ascites is a fluid, which builds up in the abdomen and contains cancer cells in the form of single cells or multicellular clusters called spheroids. Malignant ascites has been observed in patients suffering from ovarian, cervical, gastric, colorectal, pancreatic, endometrial, or primary liver cancer. The spheroids are believed to play a major role in chemo resistance and metastasis of the cancer. To ease the discomfort of patients, malignant ascites (MA) is often drained from the abdomen using a procedure called paracentesis. MA retrieved via this minimal invasive procedure is a great source for cancer spheroids, which can be used for testing chemotherapeutic drugs and drug combinations. Herein, the existing workflow is adapted to make concurrent monitoring of drug accumulation, drug response, and drug metabolites feasible using primary spheroids or spheroids grown without a scaffolding matrix. To achieve this, those spheroids are embedded in matrigel, before fixing them with formalin. This makes it possible to process, store, and ship samples at room temperature. This new approach might be used to choose the best targeted therapy for each patient and thereby facilitate personalized medicine.
关键词： cancer spheroids,FFPE,MALDI MSI
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Optical Neural Network by Disordered Tumor Spheroids
摘要： Optical neuromorphic computing processes information at the speed of light, but requires a careful design and fabrication of the deep layers, which strongly hampers the development of large-scale photonic learning machines [1,2]. New paradigms, as reservoir computing [3], suggest that brain-inspired complex systems such as disordered and biological materials may realize artificial neural networks with thousands of computational nodes trained only at the input and at the readout. Here we use real-brain cells for realizing a bio-inspired optical neural network able to extract information about cancer morphodynamics and chemotherapy that is inaccessible to imaging methods [4]. Specifically, we consider glioblastoma tumor spheroids as three-dimensional deep computational reservoirs with thousands of cells acting as wave-mixing nodes for the input light beam. These tumor models are largely used in oncology and are a promising platform for studying complex cell-to-cell interactions and anti-cancer therapeutics. In our hybrid bio/photonic scheme, the tumor model cellular layers are the diffractive deep layers of the optical neural network [Fig. 1(a)]. By exploiting structured light propagation in the disordered assembly [5], we show that the random neural network is a universal optical interpolant able to perform programmed functions in the transmission plane. Through external stimuli on the tumour brain cells – either of thermal or chemical nature – we control the internal weights of the living reservoir and its functionality. Once trained, the response of the living optical neural network follows subcellular cancer morphodynamics, not detected by more invasive and destructive optical imaging. In Fig. 1(b) we demonstrate morphodynamics sensing by inducing hyperthermia with an infrared pump laser. Moreover, we track cellular processes in the tumour model beyond the simple unconstrained growth; in Fig. 1(c) the network output allows to quantify the effect of chemotherapy inhibiting tumour growth. In this case, we realize a non-invasive smart probe for cytotoxicity assay, which is at least one order of magnitude more sensitive with respect to conventional imaging. Our random and hybrid photonic/living system is a novel artificial machine for computing and for the real-time investigation of tumour dynamics.
关键词： optical neural network,cancer morphodynamics,disordered tumor spheroids,reservoir computing,neuromorphic computing,chemotherapy
更新于2025-09-11 14:15:04
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Photodynamic Therapy Based on Arrabidaea chica (Crajiru) Extract Nanoemulsion: In vitro Activity against Monolayers and Spheroids of Human Mammary Adenocarcinoma MCF-7 Cells
摘要： Natural products have been sources of numerous drugs over the history. However, little is known about the therapeutic potential of Amazon forest species. This work aimed at testing the potential of the hydrophobic extract of Arrabidaea chica (ACE), an Amazon plant, as a source of photosensitizers for anticancer photodynamic therapy. ACE was tested as a nanoemulsion (ACE-NE) produced by phase inversion temperature. It was found that ACE-NE intensely absorbs red light and, under photoactivation (λ 660 nm, 4.5 J/cm2), produces reactive oxygen species. Photoactivated ACE-NE presented, in vitro, a CC50 of 1.3 μg ACE/mL against human breast adenocarcinoma MCF-7 cells, and was effective in lysing MCF-7 spheroids. In the dark, ACE was toxic neither to human mammary epithelial MCF-10A cells nor to MCF-7 cells. On that ground, this work is the first to show that A. chica is a source of photosensitizers potentially useful for anticancer photodynamic therapy.
关键词： Amazon natural extracts,Cancer,Spontaneous emulsification,Human breast adenocarcinoma MCF-7 cells,Spheroids
更新于2025-09-09 09:28:46
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Assessing super-spheroids in modelling the scattering matrices of dust aerosols
摘要： Atmospheric dust particles are known to have diverse and irregular morphologies. In order to account for non-sphericity, the spheroidal model with an aspect ratio distribution has been extensively used for modeling the optical properties of dust. The spheroidal model is superior to the spherical shape assumption but it requires further improvement. In this study, super-spheroids’ modeling capabilities were systematically examined by comprehensively comparing the spheroid’s and super-spheroid’s scattering matrices. Super-spheroids have one more degree of freedom than spheroids and can be non-spherical at an aspect ratio of unity. The invariant imbedding T-matrix and the improved geometrical optics methods were employed to compute super-spheroids’ single-scattering properties with a wide distribution of aspect ratios and a number of roundness parameters. We then assessed the spheroidal and super-spheroidal models’ applicability for simulating the scattering matrices of 25 dust samples from the Amsterdam-Granada Light Scattering Database. It was found that extreme aspect ratios for spheroids in reproducing the measurements were unnecessary if super-spheroids were used. Even with equi-probable aspect ratio distribution, super-spheroids with constrained roundness parameters (from 2.4 to 3.0) could achieve better performances in concurrently matching six nonzero scattering matrix elements from the laboratory measurements. Moreover, super-spheroids demonstrated better performances than spheroids in achieving spectral consistency for modeling dust scattering matrices. Therefore, super-spheroids appear to be highly promising for atmospheric radiative transfer and remote sensing applications.
关键词： scattering matrices,super-spheroids,optical properties,radiative transfer,dust aerosols,remote sensing
更新于2025-09-09 09:28:46
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BODIPY with Tuned Amphiphilicity as Fluorogenic Plasma Membrane Probe
摘要： Staining of the plasma membrane (PM) is essential in bio-imaging as it delimits the cell surface and provides various information regarding the cell morphology and status. Herein, the lipophilicity of a green-emitting BODIPY fluorophore was tuned by gradual functionalization with anchors composed of zwitterionic and aliphatic groups, thus yielding three different amphiphilic dyes. We found that BODIPY bearing one or three anchors failed in efficiently staining the PM: derivative with one anchor showed low affinity to PM and exhibited strong fluorescence in water due to high solubility, whereas BODIPY with three anchors aggregated strongly in media and precipitated before binding to PM. In sharp contrast, the BODIPY bearing two anchors (B-2AZ, MemBright-488) formed virtually non-fluorescent soluble aggregates in aqueous medium that quickly de-aggregated in the presence of PM leading to bright soluble molecular form (quantum yield of 0.92). This fluorogenic response allowed for efficient probing of the PM at low concentration (20 nM) with high signal to background ratio images in mono- as well as two-photon excitation microscopy. B-2AZ proved to selectively stain the PM in a more homogeneous manner than the commercially available fluorescently labelled lectin WGA. Finally, it was successfully used in 3D-imaging to reveal fine intercellular tunneling nanotubes in KB cells and to stain the PM in glioblastoma cells in spheroids.
关键词： tunneling nanotubes,two-photon imaging,spheroids,Plasma membrane probe,fluorogenic probe
更新于2025-09-04 15:30:14