1
|
Agarwal A, Kasaei L, He X, Kitichotkul R, Hitit OK, Peng M, Schultz JA, Feldman LC, Goyal VK. Shot noise-mitigated secondary electron imaging with ion count-aided microscopy. Proc Natl Acad Sci U S A 2024; 121:e2401246121. [PMID: 39052832 PMCID: PMC11295032 DOI: 10.1073/pnas.2401246121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 07/01/2024] [Indexed: 07/27/2024] Open
Abstract
Modern science is dependent on imaging on the nanoscale, often achieved through processes that detect secondary electrons created by a highly focused incident charged particle beam. Multiple types of measurement noise limit the ultimate trade-off between the image quality and the incident particle dose, which can preclude useful imaging of dose-sensitive samples. Existing methods to improve image quality do not fundamentally mitigate the noise sources. Furthermore, barriers to assigning a physically meaningful scale make the images qualitative. Here, we introduce ion count-aided microscopy (ICAM), which is a quantitative imaging technique that uses statistically principled estimation of the secondary electron yield. With a readily implemented change in data collection, ICAM substantially reduces source shot noise. In helium ion microscopy, we demonstrate 3[Formula: see text] dose reduction and a good match between these empirical results and theoretical performance predictions. ICAM facilitates imaging of fragile samples and may make imaging with heavier particles more attractive.
Collapse
Affiliation(s)
- Akshay Agarwal
- Department of Electrical and Computer Engineering, Boston University, Boston, MA02215
| | - Leila Kasaei
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ08854
| | - Xinglin He
- Department of Electrical and Computer Engineering, Boston University, Boston, MA02215
| | | | - Oğuz Kağan Hitit
- Department of Electrical and Computer Engineering, Boston University, Boston, MA02215
| | - Minxu Peng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA02215
| | | | - Leonard C. Feldman
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ08854
| | - Vivek K Goyal
- Department of Electrical and Computer Engineering, Boston University, Boston, MA02215
| |
Collapse
|
2
|
Sartsanga C, Phengchat R, Fukui K, Wako T, Ohmido N. Surface structures consisting of chromatin fibers in isolated barley (Hordeum vulgare) chromosomes revealed by helium ion microscopy. Chromosome Res 2021; 29:81-94. [PMID: 33615407 DOI: 10.1007/s10577-021-09649-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/19/2021] [Accepted: 01/27/2021] [Indexed: 11/24/2022]
Abstract
The chromosome compaction of chromatin fibers results in the formation of the nucleosome, which consists of a DNA unit coiled around a core of histone molecules associated with linker histone. The compaction of chromatin fibers has been a topic of controversy since the discovery of chromosomes in the 19th century. Although chromatin fibers were first identified using electron microscopy, the chromatin fibers on the surface of chromosome structures in plants remain unclear due to shrinking and breaking caused by prior chromosome isolation or preparation with alcohol and acid fixation, and critical point drying occurred into dehydration and denatured chromosomal proteins. This study aimed to develop a high-quality procedure for the isolation and preparation of plant chromosomes, maintaining the native chromosome structure, to elucidate the organization of chromatin fibers on the surface of plant chromosomes by electron microscopy. A simple technique to isolate intact barley (Hordeum vulgare) chromosomes with a high yield was developed, allowing chromosomes to be observed with a high-resolution scanning ion microscopy and helium ion microscopy (HIM) imaging technology, based on a scanning helium ion beam. HIM images from the surface chromatin fibers were analyzed to determine the size and alignment of the chromatin fibers. The unit size of the chromatin fibers was 11.6 ± 3.5 nm and was closely aligned to the chromatin network model. Our findings indicate that compacting the surface structure of barley via a chromatin network and observation via HIM are powerful tools for investigating the structure of chromatin.
Collapse
Affiliation(s)
- Channarong Sartsanga
- Graduate School of Human Development and Environment, Kobe University, Kobe, 657-8501, Japan
| | - Rinyaporn Phengchat
- Graduate School of Human Development and Environment, Kobe University, Kobe, 657-8501, Japan
| | - Kiichi Fukui
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Toshiyuki Wako
- Institute of Crop Sciences, National Agriculture and Food Research Organization, 2-1-1 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan
| | - Nobuko Ohmido
- Graduate School of Human Development and Environment, Kobe University, Kobe, 657-8501, Japan.
| |
Collapse
|
3
|
Frese N, Schmerer P, Wortmann M, Schürmann M, König M, Westphal M, Weber F, Sudhoff H, Gölzhäuser A. Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:172-179. [PMID: 33614383 PMCID: PMC7871036 DOI: 10.3762/bjnano.12.13] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/28/2021] [Indexed: 05/27/2023]
Abstract
Helium ion microscopy (HIM) offers the opportunity to obtain direct views of biological samples such as cellular structures, virus particles, and microbial interactions. Imaging with the HIM combines sub-nanometer resolution, large depth of field, and high surface sensitivity. Due to its charge compensation capability, the HIM can image insulating biological samples without additional conductive coatings. Here, we present an exploratory HIM study of SARS-CoV-2 infected Vero E6 cells, in which several areas of interaction between cells and virus particles, as well as among virus particles, were imaged. The HIM pictures show the three-dimensional appearance of SARS-CoV-2 and the surface of Vero E6 cells at a multiplicity of infection of approximately 1 with great morphological detail. The absence of a conductive coating allows for a distinction between virus particles bound to the cell membrane and virus particles lying on top of the membrane. After prolonged imaging, it was found that ion-induced deposition of hydrocarbons from the vacuum renders the sample sufficiently conductive to allow for imaging even without charge compensation. The presented images demonstrate the potential of the HIM in bioimaging, especially for the imaging of interactions between viruses and their host organisms.
Collapse
Affiliation(s)
- Natalie Frese
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Bielefeld, Germany
| | - Patrick Schmerer
- Institute of Virology, Faculty of Veterinary Medicine, Justus-Liebig-University Giessen, Germany
| | - Martin Wortmann
- Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, Bielefeld, Germany
| | - Matthias Schürmann
- University Clinic for Otolaryngology, Head and Neck Surgery, Medical Faculty OWL at Bielefeld University, Germany
| | - Matthias König
- Institute of Virology, Faculty of Veterinary Medicine, Justus-Liebig-University Giessen, Germany
| | - Michael Westphal
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Bielefeld, Germany
| | - Friedemann Weber
- Institute of Virology, Faculty of Veterinary Medicine, Justus-Liebig-University Giessen, Germany
| | - Holger Sudhoff
- University Clinic for Otolaryngology, Head and Neck Surgery, Medical Faculty OWL at Bielefeld University, Germany
| | - Armin Gölzhäuser
- Physics of Supramolecular Systems and Surfaces, Faculty of Physics, Bielefeld University, Bielefeld, Germany
| |
Collapse
|
4
|
Schmidt M, Byrne JM, Maasilta IJ. Bio-imaging with the helium-ion microscope: A review. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:1-23. [PMID: 33489663 PMCID: PMC7801799 DOI: 10.3762/bjnano.12.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/26/2020] [Indexed: 06/01/2023]
Abstract
Scanning helium-ion microscopy (HIM) is an imaging technique with sub-nanometre resolution and is a powerful tool to resolve some of the tiniest structures in biology. In many aspects, the HIM resembles a field-emission scanning electron microscope (FE-SEM), but the use of helium ions rather than electrons provides several advantages, including higher surface sensitivity, larger depth of field, and a straightforward charge-compensating electron flood gun, which enables imaging of non-conductive samples, rendering HIM a promising high-resolution imaging technique for biological samples. Starting with studies focused on medical research, the last decade has seen some particularly spectacular high-resolution images in studies focused on plants, microbiology, virology, and geomicrobiology. However, HIM is not just an imaging technique. The ability to use the instrument for milling biological objects as small as viruses offers unique opportunities which are not possible with more conventional focused ion beams, such as gallium. Several pioneering technical developments, such as methods to couple secondary ion mass spectrometry (SIMS) or ionoluminescence with the HIM, also offer the possibility for new and exciting research on biological materials. In this review, we present a comprehensive overview of almost all currently published literature which has demonstrated the application of HIM for imaging of biological specimens. We also discuss some technical features of this unique type of instrument and highlight some of the new advances which will likely become more widely used in the years to come.
Collapse
Affiliation(s)
- Matthias Schmidt
- Helmholtz-Centre for Environmental Research GmbH - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - James M Byrne
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, United Kingdom
| | - Ilari J Maasilta
- Nanoscience Center, Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| |
Collapse
|
5
|
Li T, Yang J, Zhang H, Xie Y, Jin J. Bifidobacterium from breastfed infant faeces prevent high-fat-diet-induced glucose tolerance impairment, mediated by the modulation of glucose intake and the incretin hormone secretion axis. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:3308-3318. [PMID: 32108348 DOI: 10.1002/jsfa.10360] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/16/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Probiotics are defined as microorganisms that can exert health benefits for the host. Among the recognized probiotics, Bifidobacterium are the most frequently used probiotics in humans. The aim of this study was to evaluate the antidiabetic activity of Bifidobacterium strains isolated from breastfed infant faeces, both in vitro, using the Caco-2 monolayer transwell model, and in vivo, using a mice model of impaired glucose tolerance induced by a high-fat diet (HFD). RESULTS The cell-free supernatant of Bifidobacterium lactis A12 showed better inhibitory activity of α-glucosidase and inhibited the glucose absorption and transport than B. lactis BB12, which is a typical probiotic with antidiabetic capabilities. B. lactis A12 improved the impaired glucose intolerance, restored islet function and morphology with insulin resistance induced by the HFD in C57BL/6J mice. Furthermore, in small intestine tissues, the cell-free supernatant of B. lactis A12 decreased the messenger RNA expressions of sucrase-isomaltase, live B. lactis A12 cells decreased glucose transporters 2. B. lactis A12 significantly stimulated the glucagon like peptide-1 (GLP-1) secretion and upregulated proglucagon messenger RNA levels. CONCLUSION B. lactis A12 protect against the deleterious effects of HFD-induced diabetes by inhibiting the utilization, absorption, and transport of glucose by intestinal epithelial cells and promoting the expression and secretion of GLP-1. © 2020 Society of Chemical Industry.
Collapse
Affiliation(s)
- Tong Li
- Food Science and Engineering College, Beijing University of Agriculture, Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Detection and Control of Spoilage Organisms and Pesticide Residues in Agricultural Products, Beijing, China
| | - Jianjun Yang
- Food Science and Engineering College, Beijing University of Agriculture, Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Detection and Control of Spoilage Organisms and Pesticide Residues in Agricultural Products, Beijing, China
| | - Hongxing Zhang
- Food Science and Engineering College, Beijing University of Agriculture, Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Detection and Control of Spoilage Organisms and Pesticide Residues in Agricultural Products, Beijing, China
| | - Yuanhong Xie
- Food Science and Engineering College, Beijing University of Agriculture, Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Detection and Control of Spoilage Organisms and Pesticide Residues in Agricultural Products, Beijing, China
| | - Junhua Jin
- Food Science and Engineering College, Beijing University of Agriculture, Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Detection and Control of Spoilage Organisms and Pesticide Residues in Agricultural Products, Beijing, China
| |
Collapse
|
6
|
Safder M, Temelli F, Ullah A. Supercritical CO2 extraction and solvent-free rapid alternative bioepoxy production from spent hens. J CO2 UTIL 2019. [DOI: 10.1016/j.jcou.2019.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
7
|
Said N, Chatzinotas A, Schmidt M. Have an Ion on It: The Life-Cycle of Bdellovibrio bacteriovorus Viewed by Helium-Ion Microscopy. ACTA ACUST UNITED AC 2018; 3:e1800250. [PMID: 32627346 DOI: 10.1002/adbi.201800250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/11/2018] [Indexed: 11/12/2022]
Abstract
Helium-ion microscopy (HIM) has so far rarely been employed to image microbial interactions. Here, the visualization of the life-cycle of the bacterial predator Bdellovibrio bacteriovorus HD100 with Escherichia coli and Pseudomonas putida, respectively, as prey is presented. The predator is brought in contact with prey and samples are taken at selected times. The system is monitored by phase-contrast microscopy and HIM. For HIM imaging, a sample preparation protocol is established that preserves the structure of Bdellovibrio, prey, and bdelloplasts. The micrographs show the attachment of the predator to its prey, the evolution of bdelloplasts, their lysis, and the release of predator progeny. The combination of HIM with two more approaches allows for investigating predator-prey interactions from different angles: First, phase-contrast micrographs provide quantitative information for the numbers of predator, prey, and bdelloplasts. Second, a numerical model solving the retarded differential equations that describe the system's time-evolution is developed and fits the experimentally determined cell numbers. In conclusion, the high resolution, the large depth of focus, and surface sensitivity of HIM hold promise to expand future studies on so far neglected ecological interactions within the microbial food web, in particular in samples with pronounced topography such as bacterial biofilms.
Collapse
Affiliation(s)
- Nedal Said
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Antonis Chatzinotas
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany
| | - Matthias Schmidt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318, Leipzig, Germany
| |
Collapse
|
8
|
Pöpsel C, Becker J, Jeon N, Döblinger M, Stettner T, Gottschalk YT, Loitsch B, Matich S, Altzschner M, Holleitner AW, Finley JJ, Lauhon LJ, Koblmüller G. He-Ion Microscopy as a High-Resolution Probe for Complex Quantum Heterostructures in Core-Shell Nanowires. NANO LETTERS 2018; 18:3911-3919. [PMID: 29781624 DOI: 10.1021/acs.nanolett.8b01282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Core-shell semiconductor nanowires (NW) with internal quantum heterostructures are amongst the most complex nanostructured materials to be explored for assessing the ultimate capabilities of diverse ultrahigh-resolution imaging techniques. To probe the structure and composition of these materials in their native environment with minimal damage and sample preparation calls for high-resolution electron or ion microscopy methods, which have not yet been tested on such classes of ultrasmall quantum nanostructures. Here, we demonstrate that scanning helium ion microscopy (SHeIM) provides a powerful and straightforward method to map quantum heterostructures embedded in complex III-V semiconductor NWs with unique material contrast at ∼1 nm resolution. By probing the cross sections of GaAs-Al(Ga)As core-shell NWs with coaxial GaAs quantum wells as well as short-period GaAs/AlAs superlattice (SL) structures in the shell, the Al-rich and Ga-rich layers are accurately discriminated by their image contrast in excellent agreement with correlated, yet destructive, scanning transmission electron microscopy and atom probe tomography analysis. Most interestingly, quantitative He-ion dose-dependent SHeIM analysis of the ternary AlGaAs shell layers and of compositionally nonuniform GaAs/AlAs SLs reveals distinct alloy composition fluctuations in the form of Al-rich clusters with size distributions between ∼1-10 nm. In the GaAs/AlAs SLs the alloy clustering vanishes with increasing SL-period (>5 nm-GaAs/4 nm-AlAs), providing insights into critical size dimensions for atomic intermixing effects in short-period SLs within a NW geometry. The straightforward SHeIM technique therefore provides unique benefits in imaging the tiniest nanoscale features in topography, structure and composition of a multitude of diverse complex semiconductor nanostructures.
Collapse
Affiliation(s)
- Christian Pöpsel
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Jonathan Becker
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Nari Jeon
- Department of Materials Science & Engineering , Northwestern University , Evanston , Illinois 60208 , United States
| | - Markus Döblinger
- Department of Chemistry , Ludwig-Maximilian-Universität München , Butenandtstraße 5-13 , München , 81377 , Germany
| | - Thomas Stettner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Yeanitza Trujillo Gottschalk
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Bernhard Loitsch
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Sonja Matich
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Marcus Altzschner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Alexander W Holleitner
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Jonathan J Finley
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| | - Lincoln J Lauhon
- Department of Materials Science & Engineering , Northwestern University , Evanston , Illinois 60208 , United States
| | - Gregor Koblmüller
- Walter Schottky Institut, Physik Department, and Center for Nanotechnology and Nanomaterials , Technische Universität München , Am Coulombwall 4 , Garching , 85748 , Germany
| |
Collapse
|
9
|
Herrera MG, Pizzuto M, Lonez C, Rott K, Hütten A, Sewald N, Ruysschaert JM, Dodero VI. Large supramolecular structures of 33-mer gliadin peptide activate toll-like receptors in macrophages. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2018; 14:1417-1427. [DOI: 10.1016/j.nano.2018.04.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/23/2018] [Accepted: 04/16/2018] [Indexed: 02/08/2023]
|
10
|
New advances in scanning microscopy and its application to study parasitic protozoa. Exp Parasitol 2018; 190:10-33. [PMID: 29702111 DOI: 10.1016/j.exppara.2018.04.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 04/10/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
Abstract
Scanning electron microscopy has been used to observe and study parasitic protozoa for at least 40 years. However, field emission electron sources, as well as improvements in lenses and detectors, brought the resolution power of scanning electron microscopes (SEM) to a new level. Parallel to the refinement of instruments, protocols for preservation of the ultrastructure, immunolabeling, exposure of cytoskeleton and inner structures of parasites and host cells were developed. This review is focused on protozoan parasites of medical and veterinary relevance, e.g., Toxoplasma gondii, Tritrichomonas foetus, Giardia intestinalis, and Trypanosoma cruzi, compilating the main achievements in describing the fine ultrastructure of their surface, cytoskeleton and interaction with host cells. Two new resources, namely, Helium Ion Microscopy (HIM) and Slice and View, using either Focused Ion Beam (FIB) abrasion or Microtome Serial Sectioning (MSS) within the microscope chamber, combined to backscattered electron imaging of fixed (chemically or by quick freezing followed by freeze substitution and resin embedded samples is bringing an exponential amount of valuable information. In HIM there is no need of conductive coating and the depth of field is much higher than in any field emission SEM. As for FIB- and MSS-SEM, high resolution 3-D models of areas and volumes larger than any other technique allows can be obtained. The main results achieved with all these technological tools and some protocols for sample preparation are included in this review. In addition, we included some results obtained with environmental/low vacuum scanning microscopy and cryo-scanning electron microscopy, both promising, but not yet largely employed SEM modalities.
Collapse
|
11
|
Sato C, Sato M, Ogawa S. Imaging of immunogold labeling in cells and tissues by helium ion microscopy. Int J Mol Med 2018; 42:309-321. [PMID: 29620251 PMCID: PMC5979831 DOI: 10.3892/ijmm.2018.3604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 03/16/2018] [Indexed: 02/02/2023] Open
Abstract
Helium ion microscopy (HIM) scans samples with a fine ion beam exploiting the very short de Broglie wavelength of helium ions. Because the radiation induces only a small sample region to emit secondary electrons (SEs), very high resolution is expected. In order to explore the applications of SE-HIM in biology, COS7 kidney fibroblast cells and C2C12 myoblast cells cultured on a silicon (Si) nitride (SiN)/Si bilayer were dried and directly observed in high vacuum, without coating or staining. High contrast, high depth-of-field images were obtained revealing the nucleus, endoplasmic reticulum, cytoskeleton and putative mitochondria above a bright background from the support. Gold-tagged antibodies were employed to aid organelle identification. Signals from the gold tags were most clearly distinguishable by secondary electron (SE)-HIM when cells were grown on thin SiN film, and the minimum gap measured between gold particles showed the resolution to be 2 nm. Wheat germ agglutinin-gold labeling revealed clusters of gold particles ~50–200 nm in diameter on COS7 cells, which might represent assemblies of glycosylated proteins, suggesting the formation of membrane raft structures that include membrane proteins. SE-HIM also delivered high contrast images of unstained, uncoated, thin sections of Epon-embedded mouse kidney tissues mounted on a SiN/Si bilayer, revealing the details of sub-tissues and cell organelles. A charge-coupled mechanism explaining the observed SE-HIM contrast is proposed. Ionoluminescence-HIM was also performed targeting zinc oxide particles on cells. In conclusion, the high depth-of-field, high-resolution imaging achieved using HIM may have applications in various fields, including soft materials.
Collapse
Affiliation(s)
- Chikara Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Mari Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan
| | - Shinichi Ogawa
- Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8569, Japan
| |
Collapse
|
12
|
Prina-Mello A, Jain N, Liu B, Kilpatrick JI, Tutty MA, Bell AP, Jarvis SP, Volkov Y, Movia D. Culturing substrates influence the morphological, mechanical and biochemical features of lung adenocarcinoma cells cultured in 2D or 3D. Tissue Cell 2017; 50:15-30. [PMID: 29429514 DOI: 10.1016/j.tice.2017.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/31/2017] [Accepted: 11/26/2017] [Indexed: 01/04/2023]
Abstract
Alternative models such as three-dimensional (3D) cell cultures represent a distinct milestone towards capturing the realities of cancer biology in vitro and reduce animal experimentation in the preclinical stage of drug discovery. Significant work remains to be done to understand how substrates used in in vitro alternatives influence cancer cells phenotype and drug efficacy responses, so that to accurately link such models to specific in vivo disease scenarios. Our study describes how the morphological, mechanical and biochemical properties of adenocarcinoma (A549) cells change in response to a 3D environment and varying substrates. Confocal Laser Scanning (LSCM), He-Ion (HIM) and Atomic Force (AFM) microscopies, supported by ELISA and Western blotting, were used. These techniques enabled us to evaluate the shape, cytoskeletal organization, roughness, stiffness and biochemical signatures of cells grown within soft 3D matrices (PuraMatrix™ and Matrigel™), and to compare them to those of cells cultured on two-dimensional glass substrates. Cell cultures are also characterized for their biological response to docetaxel, a taxane-type drug used in Non-Small-Cell Lung Cancer (NSCLC) treatment. Our results offer an advanced biophysical insight into the properties and potential application of 3D cultures of A549 cells as in vitro alternatives in lung cancer research.
Collapse
Affiliation(s)
- Adriele Prina-Mello
- CRANN Institute and AMBER Centre, Trinity College Dublin, Ireland; Laboratory for Biological Characterization of Advanced Materials (LBCAM), Trinity Translational Medicine Institute (TTMI), Trinity College Dublin, Ireland; Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland
| | - Namrata Jain
- CRANN Institute and AMBER Centre, Trinity College Dublin, Ireland
| | - Baiyun Liu
- School of Physics, University College Dublin, Ireland
| | - Jason I Kilpatrick
- Conway Institute of Biomedical and Biomolecular Research, University College Dublin, Ireland
| | - Melissa A Tutty
- Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland
| | - Alan P Bell
- CRANN Institute and AMBER Centre, Trinity College Dublin, Ireland; Advanced Microscopy Laboratory (AML), Trinity College Dublin, Ireland
| | - Suzanne P Jarvis
- Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland; School of Physics, University College Dublin, Ireland
| | - Yuri Volkov
- CRANN Institute and AMBER Centre, Trinity College Dublin, Ireland; Laboratory for Biological Characterization of Advanced Materials (LBCAM), Trinity Translational Medicine Institute (TTMI), Trinity College Dublin, Ireland; Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland
| | - Dania Movia
- Laboratory for Biological Characterization of Advanced Materials (LBCAM), Trinity Translational Medicine Institute (TTMI), Trinity College Dublin, Ireland; Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Ireland.
| |
Collapse
|
13
|
O'Connell R, Chen Y, Zhang H, Zhou Y, Fox D, Maguire P, Wang JJ, Rodenburg C. Comparative study of image contrast in scanning electron microscope and helium ion microscope. J Microsc 2017; 268:313-320. [PMID: 29154504 DOI: 10.1111/jmi.12660] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/27/2017] [Accepted: 10/02/2017] [Indexed: 11/29/2022]
Abstract
Images of Ga+ -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga+ density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast.
Collapse
Affiliation(s)
- R O'Connell
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - Y Chen
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland.,Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing, China
| | - H Zhang
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - Y Zhou
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland.,School of Material Science and Engineering, Nanchang University, Nanchang, Jiangxi, China
| | - D Fox
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - P Maguire
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - J J Wang
- School of Physics and CRANN & AMBER, Trinity College Dublin, Dublin, Republic of Ireland
| | - C Rodenburg
- Department of Materials Science and Engineering, University of Sheffield, Sheffield, U.K
| |
Collapse
|
14
|
Tsuji K, Suleiman H, Miner JH, Daley JM, Capen DE, Păunescu TG, Lu HAJ. Ultrastructural Characterization of the Glomerulopathy in Alport Mice by Helium Ion Scanning Microscopy (HIM). Sci Rep 2017; 7:11696. [PMID: 28916834 PMCID: PMC5601433 DOI: 10.1038/s41598-017-12064-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/01/2017] [Indexed: 01/19/2023] Open
Abstract
The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases. Here we report the application of newly developed helium ion scanning microscopy (HIM) to examine the glomerulopathy in a Col4a3 mutant/Alport syndrome mouse model. Our study revealed unprecedented details of glomerular abnormalities in Col4a3 mutants including distorted podocyte cell bodies and disorganized primary processes. Strikingly, we observed abundant filamentous microprojections arising from podocyte cell bodies and processes, and presence of unique bridging processes that connect the primary processes and foot processes in Alport mice. Furthermore, we detected an altered glomerular endothelium with disrupted sub-endothelial integrity. More importantly, we were able to clearly visualize the complex, three-dimensional podocyte and endothelial interface by HIM. Our study demonstrates that HIM provides nanometer resolution to uncover and rediscover critical ultrastructural characteristics of the glomerulopathy in Col4a3 mutant mice.
Collapse
Affiliation(s)
- Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hani Suleiman
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey H Miner
- Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - James M Daley
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Diane E Capen
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Teodor G Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hua A Jenny Lu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
15
|
Tsuji K, Păunescu TG, Suleiman H, Xie D, Mamuya FA, Miner JH, Lu HAJ. Re-characterization of the Glomerulopathy in CD2AP Deficient Mice by High-Resolution Helium Ion Scanning Microscopy. Sci Rep 2017; 7:8321. [PMID: 28814739 PMCID: PMC5559584 DOI: 10.1038/s41598-017-08304-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/06/2017] [Indexed: 01/22/2023] Open
Abstract
Helium ion scanning microscopy (HIM) is a novel technology that directly visualizes the cell surface ultrastructure without surface coating. Despite its very high resolution, it has not been applied extensively to study biological or pathology samples. Here we report the application of this powerful technology to examine the three-dimensional ultrastructural characteristics of proteinuric glomerulopathy in mice with CD2-associated protein (CD2AP) deficiency. HIM revealed the serial alteration of glomerular features including effacement and disorganization of the slit diaphragm, followed by foot process disappearance, flattening and fusion of major processes, and eventual transformation into a podocyte sheet as the disease progressed. The number and size of the filtration slit pores decreased. Strikingly, numerous “bleb” shaped microprojections were observed extending from podocyte processes and cell body, indicating significant membrane dynamics accompanying CD2AP deficiency. Visualizing the glomerular endothelium and podocyte-endothelium interface revealed the presence of endothelial damage, and disrupted podocyte and endothelial integrity in 6 week-old Cd2ap-KO mice. We used the HIM technology to investigate at nanometer scale resolution the ultrastructural alterations of the glomerular filtration apparatus in mice lacking the critical slit diaphragm-associated protein CD2AP, highlighting the great potential of HIM to provide new insights into the biology and (patho)physiology of glomerular diseases.
Collapse
Affiliation(s)
- Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Teodor G Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hani Suleiman
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Dongping Xie
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Fahmy A Mamuya
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hua A Jenny Lu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
16
|
Dykas MM, Poddar K, Yoong SL, Viswanathan V, Mathew S, Patra A, Saha S, Pastorin G, Venkatesan T. Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence. J Microsc 2017; 269:14-22. [PMID: 28703381 DOI: 10.1111/jmi.12604] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/08/2017] [Accepted: 06/22/2017] [Indexed: 01/28/2023]
Abstract
Carbon nanotubes (CNTs) have become an important nano entity for biomedical applications. Conventional methods of their imaging, often cannot be applied in biological samples due to an inadequate spatial resolution or poor contrast between the CNTs and the biological sample. Here we report a unique and effective detection method, which uses differences in conductivities of carbon nanotubes and HeLa cells. The technique involves the use of a helium ion microscope to image the sample with the surface charging artefacts created by the He+ and neutralised by electron flood gun. This enables us to obtain a few nanometre resolution images of CNTs in HeLa Cells with high contrast, which was achieved by tailoring the He+ fluence. Charging artefacts can be efficiently removed for conductive CNTs by a low amount of electrons, the fluence of which is not adequate to discharge the cell surface, resulting in high image contrast. Thus, this technique enables rapid detection of any conducting nano structures on insulating cellular background even in large fields of view and fine spatial resolution. The technique demonstrated has wider applications for researchers seeking enhanced contrast and high-resolution imaging of any conducting entity in a biological matrix - a commonly encountered issue of importance in drug delivery, tissue engineering and toxicological studies.
Collapse
Affiliation(s)
- M M Dykas
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore
| | - K Poddar
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore.,Department of Orthopedic Surgery, National University of Singapore, Singapore
| | - S L Yoong
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Department of Pharmacy, National University of Singapore, Singapore
| | - V Viswanathan
- Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore.,Department of Electrical and Computer Engineering, National University of Singapore, Singapore
| | - S Mathew
- Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore
| | - A Patra
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore
| | - S Saha
- Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore
| | - G Pastorin
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore.,Department of Pharmacy, National University of Singapore, Singapore
| | - T Venkatesan
- Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.,Nanoscience & Nanotechnology Initiative, National University of Singapore, Singapore.,Department of Electrical and Computer Engineering, National University of Singapore, Singapore.,Department of Materials Science and Engineering, National University of Singapore, Singapore.,Department of Physics, National University of Singapore, Singapore
| |
Collapse
|
17
|
Leppänen M, Sundberg LR, Laanto E, de Freitas Almeida GM, Papponen P, Maasilta IJ. Imaging Bacterial Colonies and Phage-Bacterium Interaction at Sub-Nanometer Resolution Using Helium-Ion Microscopy. ACTA ACUST UNITED AC 2017; 1:e1700070. [PMID: 32646179 DOI: 10.1002/adbi.201700070] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/01/2017] [Indexed: 11/11/2022]
Abstract
Imaging of microbial interactions has so far been based on well-established electron microscopy methods. This study presents a new way to study bacterial colonies and interactions between bacteria and their viruses, bacteriophages (phages), in situ on agar plates using helium ion microscopy (HIM). In biological imaging, HIM has advantages over traditional scanning electron microscopy with its sub-nanometer resolution, increased surface sensitivity, and the possibility to image nonconductive samples. Furthermore, by controlling the He beam dose or by using heavier Ne ions, the HIM instrument provides the possibility to mill out material in the samples, allowing for subsurface imaging and in situ sectioning. Here, the first HIM-images of bacterial colonies and phage-bacterium interactions are presented at different stages of the infection as they occur on an agar culture. The feasibility of neon and helium milling is also demonstrated to reveal the subsurface structures of bacterial colonies on agar substrate, and in some cases also structure inside individual bacteria after cross-sectioning. The study concludes that HIM offers great opportunities to advance the studies of microbial imaging, in particular in the area of interaction of viruses with cells.
Collapse
Affiliation(s)
- Miika Leppänen
- Nanoscience Center, Department of Physics, University of Jyvaskyla, P. O. Box 35, FI-40014, Jyväskylä, Finland.,Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Lotta-Riina Sundberg
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Elina Laanto
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Gabriel Magno de Freitas Almeida
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Petri Papponen
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Ilari J Maasilta
- Nanoscience Center, Department of Physics, University of Jyvaskyla, P. O. Box 35, FI-40014, Jyväskylä, Finland
| |
Collapse
|
18
|
Charlier P, Weil R, Deblock R, Augias A, Deo S. Helium ion microscopy (HIM): Proof of the applicability on altered human remains (hairs of Holy Maria-Magdalena). Leg Med (Tokyo) 2016; 24:84-85. [PMID: 28081796 DOI: 10.1016/j.legalmed.2016.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 12/10/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Affiliation(s)
- P Charlier
- Section of Medical and Forensic Anthropology, UFR of Health Sciences (UVSQ & EA 4569 Paris-Descartes), 2 avenue de la source de la Bièvre, 78180 Montigny-Le-Bretonneux, France; CASH & IPES, avenue de la République, 92000 Nanterre, France.
| | - R Weil
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - R Deblock
- Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - A Augias
- Section of Medical and Forensic Anthropology, UFR of Health Sciences (UVSQ & EA 4569 Paris-Descartes), 2 avenue de la source de la Bièvre, 78180 Montigny-Le-Bretonneux, France
| | - S Deo
- Section of Medical and Forensic Anthropology, UFR of Health Sciences (UVSQ & EA 4569 Paris-Descartes), 2 avenue de la source de la Bièvre, 78180 Montigny-Le-Bretonneux, France
| |
Collapse
|
19
|
Schwaiger R, Schneider J, Bourret GR, Diwald O. Hydration of magnesia cubes: a helium ion microscopy study. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:302-9. [PMID: 27335725 PMCID: PMC4901542 DOI: 10.3762/bjnano.7.28] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/10/2016] [Indexed: 05/09/2023]
Abstract
Physisorbed water originating from exposure to the ambient can have a strong impact on the structure and chemistry of oxide nanomaterials. The effect can be particularly pronounced when these oxides are in physical contact with a solid substrate such as the ones used for immobilization to perform electron or ion microscopy imaging. We used helium ion microscopy (HIM) and investigated morphological changes of vapor-phase-grown MgO cubes after vacuum annealing and pressing into foils of soft and high purity indium. The indium foils were either used as obtained or, for reference, subjected to vacuum drying. After four days of storage in the vacuum chamber of the microscope and at a base pressure of p < 10(-7) mbar, we observed on these cubic particles the attack of residual physisorbed water molecules from the indium substrate. As a result, thin magnesium hydroxide layers spontaneously grew, giving rise to characteristic volume expansion effects, which depended on the size of the particles. Rounding of the originally sharp cube edges leads to a significant loss of the morphological definition specific to the MgO cubes. Comparison of different regions within one sample before and after exposure to liquid water reveals different transformation processes, such as the formation of Mg(OH)2 shells that act as diffusion barriers for MgO dissolution or the evolution of brucite nanosheets organized in characteristic flower-like microstructures. The findings underline the significant metastability of nanomaterials under both ambient and high-vacuum conditions and show the dramatic effect of ubiquitous water films during storage and characterization of oxide nanomaterials.
Collapse
Affiliation(s)
- Ruth Schwaiger
- Institute for Applied Materials (IAM) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Johannes Schneider
- Department of Chemistry and Physics of Materials, University of Salzburg, Hellbrunnerstrasse 34/ III, A-5020 Salzburg, Austria
| | - Gilles R Bourret
- Department of Chemistry and Physics of Materials, University of Salzburg, Hellbrunnerstrasse 34/ III, A-5020 Salzburg, Austria
| | - Oliver Diwald
- Department of Chemistry and Physics of Materials, University of Salzburg, Hellbrunnerstrasse 34/ III, A-5020 Salzburg, Austria
| |
Collapse
|
20
|
de Souza W, Attias M. New views of the Toxoplasma gondii parasitophorous vacuole as revealed by Helium Ion Microscopy (HIM). J Struct Biol 2015; 191:76-85. [PMID: 26004092 DOI: 10.1016/j.jsb.2015.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 11/27/2022]
Abstract
The Helium Ion Microscope (HIM) is a new technology that uses a highly focused helium ion beam to scan and interact with the sample, which is not coated. The images have resolution and depth of field superior to field emission scanning electron microscopes. In this paper, we used HIM to study LLC-MK2 cells infected with Toxoplasma gondii. These samples were chemically fixed and, after critical point drying, were scraped with adhesive tape to expose the inner structure of the cell and parasitophorous vacuoles. We confirmed some of the previous findings made by field emission-scanning electron microscopy and showed that the surface of the parasite is rich in structures suggestive of secretion, that the nanotubules of the intravacuolar network (IVN) are not always straight, and that bifurcations are less frequent than previously thought. Fusion of the tubules with the parasite membrane or the parasitophorous vacuole membrane (PVM) was also infrequent. Tiny adhesive links were observed for the first time connecting the IVN tubules. The PVM showed openings of various sizes that even allowed the observation of endoplasmic reticulum membranes in the cytoplasm of the host cell. These findings are discussed in relation to current knowledge on the cell biology of T. gondii.
Collapse
Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Biologia Estrutural e Biomagem-INBEB, and Centro Nacional de Biologia Estrutural e Biomagem-CENABIO, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Metrologia, Qualidade e Tecnologia-INMETRO, Duque de Caxias, RJ, Brazil
| | - Marcia Attias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco G, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Biologia Estrutural e Biomagem-INBEB, and Centro Nacional de Biologia Estrutural e Biomagem-CENABIO, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| |
Collapse
|
21
|
Petrov YV, Vyvenko OF. Scanning reflection ion microscopy in a helium ion microscope. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1125-1137. [PMID: 26171289 PMCID: PMC4463972 DOI: 10.3762/bjnano.6.114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/15/2015] [Indexed: 06/04/2023]
Abstract
Reflection ion microscopy (RIM) is a technique that uses a low angle of incidence and scattered ions to form an image of the specimen surface. This paper reports on the development of the instrumentation and the analysis of the capabilities and limitations of the scanning RIM in a helium ion microscope (HIM). The reflected ions were detected by their "conversion" to secondary electrons on a platinum surface. An angle of incidence in the range 5-10° was used in the experimental setup. It was shown that the RIM image contrast was determined mostly by surface morphology but not by the atomic composition. A simple geometrical analysis of the reflection process was performed together with a Monte Carlo simulation of the angular dependence of the reflected ion yield. An interpretation of the RIM image formation and a quantification of the height of the surface steps were performed. The minimum detectable step height was found to be approximately 5 nm. RIM imaging of an insulator surface without the need for charge compensation was successfully demonstrated.
Collapse
Affiliation(s)
- Yuri V Petrov
- Interdisciplinary Resource Center for Nanotechnology, Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| | - Oleg F Vyvenko
- Faculty of Physics, Saint-Petersburg State University, Ulyanovskaya 1, Saint-Petersburg 198504, Russia
| |
Collapse
|
22
|
Păunescu TG, Shum WWC, Huynh C, Lechner L, Goetze B, Brown D, Breton S. High-resolution helium ion microscopy of epididymal epithelial cells and their interaction with spermatozoa. Mol Hum Reprod 2014; 20:929-37. [PMID: 25015675 PMCID: PMC4172170 DOI: 10.1093/molehr/gau052] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 06/20/2014] [Accepted: 07/01/2014] [Indexed: 01/19/2023] Open
Abstract
We examined the rat and mouse epididymis using helium ion microscopy (HIM), a novel imaging technology that uses a scanning beam of He(+) ions to produce nanometer resolution images of uncoated biological samples. Various tissue fixation, sectioning and dehydration methods were evaluated for their ability to preserve tissue architecture. The cauda epididymidis was luminally perfused in vivo to remove most spermatozoa and the apical surface of the epithelial lining was exposed. Fixed epididymis samples were then subjected to critical point drying (CPD) and HIM. Apical stereocilia in principal cells and smaller apical membrane extensions in clear cells were clearly distinguishable in both rat and mouse epididymis using this technology. After perfusion with an activating solution containing CPT-cAMP, a permeant analog of cAMP, clear cells exhibited an increase in the number and size of membrane ruffles or microplicae. In contrast, principal cells did not exhibit detectable structural modifications. High-resolution HIM imaging clearly showed the ultrastructure of residual sperm cells, including the presence of concentric rings on the midpiece, and of cytoplasmic droplets in some spermatozoa. Close epithelium-sperm interactions were also detected. We found a number of sperm cells whose heads were anchored within the epididymal epithelium. In certain cases, the surface of the sperm cytoplasmic droplet was covered with vesicle-like structures whose size is consistent with that of epididymosomes. In conclusion, we describe here the first application of HIM technology to the study of the structure and morphology of the rodent epididymis. HIM technology represents a major imaging breakthrough that can be successfully applied to study the epididymis and spermatozoa, with the goal of advancing our understanding of their structure and function.
Collapse
Affiliation(s)
- Teodor G Păunescu
- Department of Medicine, Program in Membrane Biology and Division of Nephrology, Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Center, CPZN 8204, 185 Cambridge St, Boston, MA 02114, USA
| | - Winnie W C Shum
- Department of Medicine, Program in Membrane Biology and Division of Nephrology, Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Center, CPZN 8204, 185 Cambridge St, Boston, MA 02114, USA Present address: School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | | | | | | | - Dennis Brown
- Department of Medicine, Program in Membrane Biology and Division of Nephrology, Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Center, CPZN 8204, 185 Cambridge St, Boston, MA 02114, USA
| | - Sylvie Breton
- Department of Medicine, Program in Membrane Biology and Division of Nephrology, Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Simches Research Center, CPZN 8204, 185 Cambridge St, Boston, MA 02114, USA
| |
Collapse
|
23
|
Lawrence MJ, Kumar S, Hawkins K, Boden S, Rutt H, Mills G, Sabra A, Morris RH, Davidson SJ, Badiei N, Brown MR, Williams PR, Evans PA. A new structural biomarker that quantifies and predicts changes in clot strength and quality in a model of progressive haemodilution. Thromb Res 2014; 134:488-94. [DOI: 10.1016/j.thromres.2014.05.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/15/2014] [Accepted: 05/22/2014] [Indexed: 10/25/2022]
|
24
|
Dwiranti A, Hamano T, Takata H, Nagano S, Guo H, Onishi K, Wako T, Uchiyama S, Fukui K. The effect of magnesium ions on chromosome structure as observed by helium ion microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:184-188. [PMID: 24229477 DOI: 10.1017/s1431927613013792] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
One of the few conclusions known about chromosome structure is that Mg2+ is required for the organization of chromosomes. Scanning electron microscopy is a powerful tool for studying chromosome morphology, but being nonconductive, chromosomes require metal/carbon coating that may conceal information about the detailed surface structure of the sample. Helium ion microscopy (HIM), which has recently been developed, does not require sample coating due to its charge compensation system. Here we investigated the structure of isolated human chromosomes under different Mg2+ concentrations by HIM. High-contrast and resolution images from uncoated samples obtained by HIM enabled investigation on the effects of Mg2+ on chromosome structure. Chromatin fiber information was obtained more clearly with uncoated than coated chromosomes. Our results suggest that both overall features and detailed structure of chromatin are significantly affected by different Mg2+ concentrations. Chromosomes were more condensed and a globular structure of chromatin with 30 nm diameter was visualized with 5 mM Mg2+ treatment, while 0 mM Mg2+ resulted in a less compact and more fibrous structure 11 nm in diameter. We conclude that HIM is a powerful tool for investigating chromosomes and other biological samples without requiring metal/carbon coating.
Collapse
Affiliation(s)
- Astari Dwiranti
- Laboratory of Dynamic Cell Biology, Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tohru Hamano
- Laboratory of Dynamic Cell Biology, Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hideaki Takata
- Laboratory of Dynamic Cell Biology, Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shoko Nagano
- Surface Characterization Group, Nano Characterization Unit, Advanced Key Technologies Division, National Institute for Materials Science, Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Hongxuan Guo
- Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Keiko Onishi
- Surface Characterization Group, Nano Characterization Unit, Advanced Key Technologies Division, National Institute for Materials Science, Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Toshiyuki Wako
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Susumu Uchiyama
- Laboratory of Dynamic Cell Biology, Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kiichi Fukui
- Laboratory of Dynamic Cell Biology, Department of Biotechnology, Graduate School of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan
| |
Collapse
|
25
|
Joens MS, Huynh C, Kasuboski JM, Ferranti D, Sigal YJ, Zeitvogel F, Obst M, Burkhardt CJ, Curran KP, Chalasani SH, Stern LA, Goetze B, Fitzpatrick JAJ. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution. Sci Rep 2013; 3:3514. [PMID: 24343236 PMCID: PMC3865489 DOI: 10.1038/srep03514] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 11/26/2013] [Indexed: 11/08/2022] Open
Abstract
Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.
Collapse
Affiliation(s)
- Matthew S. Joens
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Chuong Huynh
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - James M. Kasuboski
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - David Ferranti
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - Yury J. Sigal
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Fabian Zeitvogel
- Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
| | - Martin Obst
- Center for Applied Geosciences, University Tübingen, Hoelderlinstr. 12, 72074 Tuebingen, Germany
| | - Claus J. Burkhardt
- NMI Natural and Medical Sciences Institute, Markwiesenstr. 55, 72770 Reutlingen, Germany
| | - Kevin P. Curran
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sreekanth H. Chalasani
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lewis A. Stern
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - Bernhard Goetze
- Ion Microscopy Innovation Center, Carl Zeiss Microscopy LLC, One Corporation Way, Peabody, MA 01960, USA
| | - James A. J. Fitzpatrick
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| |
Collapse
|
26
|
Hall AR. In situ thickness assessment during ion milling of a free-standing membrane using transmission helium ion microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:740-744. [PMID: 23628344 DOI: 10.1017/s1431927613000500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We describe a novel method for in situ measurement of the local thickness of a freely suspended solid-state membrane after thinning with a focused helium ion beam. The technique utilizes a custom stage for the helium ion microscope that allows the secondary electron detector used for normal imaging to collect information from ions transmitted through the sample. We find that relative brightness in the transmission image scales directly with the membrane thickness as determined by atomic force microscopy measurements.
Collapse
Affiliation(s)
- Adam R Hall
- Joint School of Nanoscience and Nanoengineering, Department of Nanoscience, University of North Carolina Greensboro, Greensboro, NC 27401, USA.
| |
Collapse
|
27
|
|
28
|
Rice WL, Van Hoek AN, Păunescu TG, Huynh C, Goetze B, Singh B, Scipioni L, Stern LA, Brown D. High resolution helium ion scanning microscopy of the rat kidney. PLoS One 2013; 8:e57051. [PMID: 23505418 PMCID: PMC3591388 DOI: 10.1371/journal.pone.0057051] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 01/17/2013] [Indexed: 01/11/2023] Open
Abstract
Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details and provide significant advances in our understanding of cell surface structures and membrane organization.
Collapse
Affiliation(s)
- William L. Rice
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alfred N. Van Hoek
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Teodor G. Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Chuong Huynh
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Bernhard Goetze
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Bipin Singh
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Larry Scipioni
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Lewis A. Stern
- Carl Zeiss Microscopy, Peabody, Massachusetts, United States of America
| | - Dennis Brown
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| |
Collapse
|
29
|
|
30
|
Fox D, Chen Y, Faulkner CC, Zhang H. Nano-structuring, surface and bulk modification with a focused helium ion beam. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2012; 3:579-585. [PMID: 23019554 PMCID: PMC3458604 DOI: 10.3762/bjnano.3.67] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 07/19/2012] [Indexed: 05/29/2023]
Abstract
We investigate the ability of a focused helium ion beam to selectively modify and mill materials. The sub nanometer probe size of the helium ion microscope used provides lateral control not previously available for helium ion irradiation experiments. At high incidence angles the helium ions were found to remove surface material from a silicon lamella leaving the subsurface structure intact for further analysis. Surface roughness and contaminants were both reduced by the irradiation process. Fabrication is also realized with a high level of patterning acuity. Implantation of helium beneath the surface of the sample is visualized in cross section allowing direct observation of the extended effects of high dose irradiation. The effect of the irradiation on the crystal structure of the material is presented. Applications of the sample modification process are presented and further prospects discussed.
Collapse
Affiliation(s)
- Daniel Fox
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Yanhui Chen
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Colm C Faulkner
- CRANN Advanced Microscopy Laboratory, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Hongzhou Zhang
- School of Physics and CRANN, Trinity College Dublin, Dublin 2, Republic of Ireland
| |
Collapse
|
31
|
Vanden Berg-Foels WS, Scipioni L, Huynh C, Wen X. Helium ion microscopy for high-resolution visualization of the articular cartilage collagen network. J Microsc 2012; 246:168-76. [PMID: 22416783 DOI: 10.1111/j.1365-2818.2012.03606.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The articular cartilage collagen network is an important research focus because network disruption results in cartilage degeneration and patient disability. The recently introduced helium ion microscope (HIM), with its smaller probe size, longer depth of field and charge neutralization, has the potential to overcome the inherent limitations of electron microscopy for visualization of collagen network features, particularly at the nanoscale. In this study, we evaluated the capabilities of the helium ion microscope for high-resolution visualization of the articular cartilage collagen network. Images of rabbit knee cartilage were acquired with a helium ion microscope; comparison images were acquired with a field emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM). Sharpness of example high-resolution helium ion microscope and field emission scanning electron microscope images was quantified using the 25-75% rise distance metric. The helium ion microscope was able to acquire high-resolution images with unprecedented clarity, with greater sharpness and three-dimensional-like detail of nanoscale fibril morphologies and fibril connections, in samples without conductive coatings. These nanoscale features could not be resolved by field emission scanning electron microscopy, and three-dimensional network structure could not be visualized with transmission electron microscopy. The nanoscale three-dimensional-like visualization capabilities of the helium ion microscope will enable new avenues of investigation in cartilage collagen network research.
Collapse
|
32
|
Marshall MM, Yang J, Hall AR. Direct and transmission milling of suspended silicon nitride membranes with a focused helium ion beam. SCANNING 2012; 34:101-106. [PMID: 22331671 DOI: 10.1002/sca.21003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 10/20/2011] [Indexed: 05/31/2023]
Abstract
Helium ion milling of suspended silicon nitride thin films is explored. Milled squares patterned by scanning helium ion microscope are subsequently investigated by atomic force microscopy and the relation between ion dose and milling depth is measured for both the direct (side of ion incidence) and transmission (side opposite to ion incidence) regimes. We find that direct-milling depth varies linearly with beam dose while transmission-milling depth varies with the square of the beam dose, resulting in a straightforward method of controlling local film thickness.
Collapse
Affiliation(s)
- Michael M Marshall
- Joint School of Nanoscience and Nanoengineering, University of North Carolina Greensboro, Greensboro, North Carolina 27401, USA
| | | | | |
Collapse
|
33
|
Boden SA, Asadollahbaik A, Rutt HN, Bagnall DM. Helium ion microscopy of Lepidoptera scales. SCANNING 2012; 34:107-20. [PMID: 21796646 DOI: 10.1002/sca.20267] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Accepted: 06/20/2011] [Indexed: 05/24/2023]
Abstract
In this report, helium ion microscopy (HIM) is used to study the micro and nanostructures responsible for structural color in the wings of two species of Lepidotera from the Papilionidae family: Papilio ulysses (Blue Mountain Butterfly) and Parides sesostris (Emerald-patched Cattleheart). Electronic charging of uncoated scales from the wings of these butterflies, due to the incident ion beam, is successfully neutralized, leading to images displaying a large depth-of-field and a high level of surface detail, which would normally be obscured by traditional coating methods used for scanning electron microscopy (SEM). The images are compared with those from variable pressure SEM, demonstrating the superiority of HIM at high magnifications. In addition, the large depth-of-field capabilities of HIM are exploited through the creation of stereo pairs that allows the exploration of the third dimension. Furthermore, the extraction of quantitative height information which matches well with cross-sectional transmission electron microscopy measurements from the literature is demonstrated.
Collapse
Affiliation(s)
- Stuart A Boden
- Electronics and Computer Science, University of Southampton, Highfield, Southampton, Hampshire, United Kingdom
| | | | | | | |
Collapse
|
34
|
Santos-Martinez MJ, Inkielewicz-Stepniak I, Medina C, Rahme K, D'Arcy DM, Fox D, Holmes JD, Zhang H, Radomski MW. The use of quartz crystal microbalance with dissipation (QCM-D) for studying nanoparticle-induced platelet aggregation. Int J Nanomedicine 2012; 7:243-55. [PMID: 22275839 PMCID: PMC3263416 DOI: 10.2147/ijn.s26679] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Interactions between blood platelets and nanoparticles have both pharmacological and toxicological significance and may lead to platelet activation and aggregation. Platelet aggregation is usually studied using light aggregometer that neither mimics the conditions found in human microvasculature nor detects microaggregates. A new method for the measurement of platelet microaggregation under flow conditions using a commercially available quartz crystal microbalance with dissipation (QCM-D) has recently been developed. The aim of the current study was to investigate if QCM-D could be used for the measurement of nanoparticle-platelet interactions. Silica, polystyrene, and gold nanoparticles were tested. The interactions were also studied using light aggregometry and flow cytometry, which measured surface abundance of platelet receptors. Platelet activation was imaged using phase contrast and scanning helium ion microscopy. QCM-D was able to measure nanoparticle-induced platelet microaggregation for all nanoparticles tested at concentrations that were undetectable by light aggregometry and flow cytometry. Microaggregates were measured by changes in frequency and dissipation, and the presence of platelets on the sensor surface was confirmed and imaged by phase contrast and scanning helium ion microscopy.
Collapse
|