Using Novel Method to Detect Different Cancer-Cell Stages of Model Human Lung Carcinoma.

BACKGROUND: Synchrotron radiation infrared (SR-IR) microspectroscopy and SR-IR spectroscopic imaging are extremely valuable techniques for determining the molecular composition of biological and biomedical samples. In this work, SR-IR is applied in the study of the lung cancer cells in different cell cycles. METHODS: We use a novel synchrotron based radiation infrared system combined synchronized model human lung carcinoma to reveal its unique character pattern. RESULTS: After using SR-IR microspectroscopy, we discovered that the ratio of protein to lipid in G1 and G2 states is around 4.0 and 6.1, respectively. Moreover, for the DNA at the wavenumber position of 1225 cm(-1) , the intensity ratio of G2 state to G1 state is approximately 1.6. These data indicate that the cell in G1 state has more lipid composition to prepare for the DNA synthesis, but the cell in G2 state has more protein composition to prepare for the mitosis. The cell has larger DNA concentration in G2 state, which can be explained for the DNA synthesis. CONCLUSION: Through our research, we demonstrate that different growth state of cancer cell presenting unique functional groups concentration profiles and distribution via using SR-IR microspectrometry. These applications will provide another ways to improve modern cancer screening in the future.

Downsizing and soft X-ray tomography for cellular uptake of interpenetrated metal-organic frameworks.

Metal-organic frameworks (MOFs) are porous materials with potential in biomedical applications such as sensing, drug delivery, and radiosensitization. However, how to tune the properties of the MOFs for such applications remains challenging. Herein, we synthesized two MOFs, Zr-PEB and Hf-PEB. Zr-PEB can be classified as porous interpenetrated zirconium frameworks (PIZOFs) and Hf-PEB is its analogue. We controlled their sizes while maintaining their crystal structure by employing a coordination modulation strategy. They were designed to serve as sensitizer for X-ray therapy and as potential drug carriers. Comprehensive characterizations of the MOFs' properties have been conducted, and the in vitro biological impacts have been studied. Since viability assay showed that Hf-PEB was more biocompatible compared to Zr-PEB, the cellular uptake of Hf-PEB by cells was evaluated using both fluorescence microscopy and soft X-ray tomography (SXT), and the three-dimensional structure of Hf-PEB in cells was observed. The results revealed the potential of Zr-PEB and Hf-PEB as nanomaterials for biomedical applications and demonstrated that SXT is an effective tool to assist the development of such materials.

Highly sensitive rare cell detection based on quantum dot probe fluorescence analysis.

This study presents an efficient and sensitive method for detecting rare cells without cell culture, in which cells are analyzed quantitatively using quantum dots (QDs) as a fluorescent probe. By the conjugation of QDs with cells, the biotin-streptavidin reaction functions as a bridge to connect QDs and cells. The cells can be quantified based on the correlation of the QD fluorescence intensity with the cell population. Non-specific adsorption and cross-reaction of QD625-streptavidin on T cell membrane are neglected by reacting with biotin anti-human CD3 and mixing with red blood cell, respectively. Additionally, the photo-activation period and pH can be controlled to enhance the fluorescence of cell populations, which increases linearly with the number of T cells from 40 to 100,000, not only in a single T cell line but also in mixing with a total of 10(6) red blood cells. Moreover, the specific T cells can be detected in less than 15 min, even though rare specific cells may number only 40 cells. Among the advantages, the proposed system for detecting rare cells include simplicity of preparation, low cost, rapid detection, and high sensitivity, all of which can facilitate the detection of circulating tumor cells in early stages of diagnosis or prognosis.

Nanoimaging granule dynamics and subcellular structures in activated mast cells using soft X-ray tomography.

Mast cells play an important role in allergic responses. During activation, these cells undergo degranulation, a process by which various kinds of mediators stored in the granules are released. Granule homeostasis in mast cells has mainly been studied by electron microscopy (EM), where the fine structures of subcellular organelles are partially destroyed during sample preparation. Migration and fusion of granules have not been studied in detail in three dimensions (3D) in unmodified samples. Here, we utilized soft X-ray tomography (SXT) coupled with fluorescence microscopy to study the detailed structures of organelles during mast cell activation. We observed granule fission, granule fusion to plasma membranes, and small vesicles budding from granules. We also detected lipid droplets, which became larger and more numerous as mast cells were activated. We observed dramatic morphological changes of mitochondria in activated mast cells and 3D-reconstruction revealed the highly folded cristae inner membrane, features of functionally active mitochondria. We also observed giant vesicles containing granules, mitochondria, and lipid droplets, which we designated as granule-containing vesicles (GCVs) and verified their presence by EM in samples prepared by cryo-substitution, albeit with a less clear morphology. Thus, our studies using SXT provide significant insights into mast cell activation at the organelle level.

Influence of oxygen on the crystalline-amorphous transition in gallium nitride films.

Oxygen is a common impurity in nitride-based materials that affects the properties of technologically important materials such as gallium nitride semiconductors. In this work, the influence of oxygen on the structural evolution of GaN films is investigated using near-edge X-ray absorption fine structure (NEXAFS). The combined spectra of Ga L3-edge, N K-edge, and O K-edge indicate that the gallium coordination, formed by a mixture of oxide and nitride bonds, is directly dependent on the concentration of oxygen in the films. Below 24 atom % oxygen, gallium atoms are tetrahedrally coordinated within the films, while at higher concentrations the octahedral environment persists.

Rapid and sensitive detection of rare cancer cells by the coupling of immunomagnetic nanoparticle separation with ELISA analysis.

This study presents a rapid and sensitive method for detecting cancer cells occurring at low concentration. The method involves the simultaneous detection of two biomarkers of T helper cancer cells. One biomarker conjugates with immunofunctionalized magnetic nanoparticles (MNPs), enabling the separation of the T helper cells from a mixed population of cells. The other biomarker is used for detection during enzyme-linked immunosorbent assay (ELISA) analysis. The specific T helper cells can be quantified according to their ELISA absorbance values following magnetic separation. The experimental results demonstrate that immunofunctionalized MNPs can function as magnetic sensors and separate specific T helper cells from a mixed population with high efficiency and high specificity. Coupled with the ELISA technique, the immunofunctionalized MNPs can simultaneously detect rare cells. Results indicated increasing absorbance with increasing T cell number (from 10 to 10(6)). The total detection time was less than 15 minutes, even at a low T cell count. The advantages of the proposed method for detecting specific cells at low concentration include ease of preparation, low cost, rapid detection, and high sensitivity. The proposed system can be adopted to detect circulating tumor cells in early tumor stages for diagnostic or prognostic purposes.

Rapid and sensitive detection of cancer cells by coupling with quantum dots and immunomagnetic separation at low concentrations.

This work presents a rapid and sensitive method for detecting cancer cells at low concentration. In this method, two biomarkers of T-help cancer cells are detected simultaneously. One biomarker is conjugated with magnetic beads to separate T-help cell from the mixed cells and the other biomarker, associated with quantum dots, is used to detect fluorescence. The specific T-help cells can be quantified using the relationship between the QD fluorescence intensity and the cell frequency following magnetic separation. The intensity of fluorescence increases linearly with the frequency of T-help cells from 10(-7) to 10(-3), and neither B cells nor red blood cells interfere with the detection of T-help cells. Moreover, the total detection time is under 15 min, even though the frequency of specific T-help cells is as low as 5×10(-7). The numerous advantages of detecting specific cells at low concentration using the presented method include ease of preparation, low cost, fast detection, and high sensitivity.

Surface characterization of immunosensor conjugated with gold nanoparticles based on cyclic voltammetry and X-ray photoelectron spectroscopy.

This investigation describes the surface characterization of rabbit immunoglobulin G (IgG) conjugated with gold nanoparticles. Goat anti-rabbit immunoglobulin G tagged with 5nm gold nanoparticles was applied to detect the IgG. Then, the autocatalyzed deposition of Au(3+) onto the surface of anti-IgGAu increased the surface area per gold nanoparticle. The immobilization chemistries and the atomic concentrations of Au(4f), P(2p), S(2p), C(1s), N(1s) and O(1s) of the resulting antibody-modified Au electrodes were determined by X-ray photoelectron spectroscopy (XPS). The sulfur that is involved in the cysteamine binding and the enlargement of the gold nanoparticles are identified using cyclic voltammetry. The results reveal that the surface area per gold particle, following the autocatalyzed deposition Au(3+) on the surface of anti-IgGAu, was approximately seven times higher than that before deposition.