scholarly journals Atomic Force Microscopy on Biological Materials Related to Pathological Conditions

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-25 ◽  
Author(s):  
Andreas Stylianou ◽  
Stylianos-Vasileios Kontomaris ◽  
Colin Grant ◽  
Eleni Alexandratou
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Surface Characterization ◽  
Amyloid Fibrils ◽  
Biological Materials ◽  
Force Microscopy ◽  
Fibrous Protein ◽  
Atomic Force ◽  
Pathological Conditions ◽  
Wide Range

Atomic force microscopy (AFM) is an easy-to-use, powerful, high-resolution microscope that allows the user to image any surface and under any aqueous condition. AFM has been used in the investigation of the structural and mechanical properties of a wide range of biological matters including biomolecules, biomaterials, cells, and tissues. It provides the capacity to acquire high-resolution images of biosamples at the nanoscale and allows at readily carrying out mechanical characterization. The capacity of AFM to image and interact with surfaces, under physiologically relevant conditions, is of great importance for realistic and accurate medical and pharmaceutical applications. The aim of this paper is to review recent trends of the use of AFM on biological materials related to health and sickness. First, we present AFM components and its different imaging modes and we continue with combined imaging and coupled AFM systems. Then, we discuss the use of AFM to nanocharacterize collagen, the major fibrous protein of the human body, which has been correlated with many pathological conditions. In the next section, AFM nanolevel surface characterization as a tool to detect possible pathological conditions such as osteoarthritis and cancer is presented. Finally, we demonstrate the use of AFM for studying other pathological conditions, such as Alzheimer’s disease and human immunodeficiency virus (HIV), through the investigation of amyloid fibrils and viruses, respectively. Consequently, AFM stands out as the ideal research instrument for exploring the detection of pathological conditions even at very early stages, making it very attractive in the area of bio- and nanomedicine.

Polymorphism and Ultrastructural Organization of Prion Protein Amyloid Fibrils: An Insight from High Resolution Atomic Force Microscopy

2006 ◽  
Vol 358 (2) ◽  
pp. 580-596 ◽  
Author(s):  
Maighdlin Anderson ◽  
Olga V. Bocharova ◽  
Natallia Makarava ◽  
Leonid Breydo ◽  
Vadim V. Salnikov ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Prion Protein ◽  
Amyloid Fibrils ◽  
Ultrastructural Organization ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Amyloid Fibrils of Glucagon Characterized by High-Resolution Atomic Force Microscopy

2006 ◽  
Vol 91 (5) ◽  
pp. 1905-1914 ◽  
Author(s):  
Kathy L. De Jong ◽  
Bev Incledon ◽  
Christopher M. Yip ◽  
Michael R. DeFelippis
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Amyloid Fibrils ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Nanomechanical Characterization of Apolipoprotein A-I Amyloid Fibrils

2020 ◽  
Keyword(s):  
Atomic Force Microscopy ◽  
Elastic Properties ◽  
Amyloid Fibrils ◽  
Cytotoxic Action ◽  
Force Microscopy ◽  
Helical Ribbon ◽  
Atomic Force ◽  
Apolipoprotein A ◽  
Wide Range ◽  
Persistent Length

Amyloid fibrils represent a special type of protein aggregates that are currently receiving enormous attention due to their strong implication in molecular etiology of a wide range of human disorders. Amyloid fibrils represent highly ordered self-assemblies sharing a core cross-β-sheet structure. Such organization of the fibrils is responsible for amyloid insolubility and exceptional mechanical properties. The remarkable rigidity of the protein fibrillar aggregates is due to intra- and interstrand hydrogen bonds which stabilize the β-strand scaffold of amyloid fibrils. Increasing evidence indicates that physical properties of amyloid assemblies, especially their mechanical characteristics, play essential role in determining their cytotoxic action. This highlights the necessity of deciphering the correlation between the elastic properties of amyloid aggregates and their cytotoxicity. In the present paper we utilized the atomic force microscopy (AFM) to visualize and analyze the amyloid fibrils of G26R/W@8 mutant of N-terminal fragment of human apolipoprotein A-I (apoA-I). The examination of AFM images revealed the existence of two polymorphic forms of apoA-I fibrils – twisted ribbon and helical ribbon. The quantitative analysis of apoA-I elastic properties was performed within the framework of worm-like model of polymer chain using the Easyworm software. The Easyworm package analyzes the images of individual polymer chains obtained by the atomic force microscopy and allows calculation of the persistent length of a chain in three regimes depending on the ratio between the contour and persistent lengths of the polymer. The set of evaluated parameters included the Young’s modulus, persistent length, bending rigidity and the second moment of inertia. All parameters calculated for the helical ribbon conformation were higher than those of the twisted ribbon. These findings suggest that helical ribbon represents a more rigid and mechanically stable configuration. The results obtained may prove of importance for a deeper understanding the mechanics-driven pathological activities of amyloid fibrils.

scholarly journals Exploring Intramolecular Methyl–Methyl Coupling on a Metal Surface for Edge-Extended Graphene Nanoribbons

2021 ◽  
Vol 03 (02) ◽  
pp. 128-133
Author(s):  
Zijie Qiu ◽  
Qiang Sun ◽  
Shiyong Wang ◽  
Gabriela Borin Barin ◽  
Bastian Dumslaff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
High Resolution ◽  
Graphene Nanoribbons ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Methyl Methyl ◽  
Atomic Force ◽  
Edge Extension

Intramolecular methyl–methyl coupling on Au (111) is explored as a new on-surface protocol for edge extension in graphene nanoribbons (GNRs). Characterized by high-resolution scanning tunneling microscopy, noncontact atomic force microscopy, and Raman spectroscopy, the methyl–methyl coupling is proven to indeed proceed at the armchair edges of the GNRs, forming six-membered rings with sp3- or sp2-hybridized carbons.

Imaging of Xenopus laevis Oocyte Plasma Membrane in Physiological-Like Conditions by Atomic Force Microscopy

2013 ◽  
Vol 19 (5) ◽  
pp. 1358-1363 ◽  
Author(s):  
Massimo Santacroce ◽  
Federica Daniele ◽  
Andrea Cremona ◽  
Diletta Scaccabarozzi ◽  
Michela Castagna ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Plasma Membrane ◽  
High Resolution ◽  
Membrane Proteins ◽  
Xenopus Laevis ◽  
Functional Study ◽  
Xenopus Laevis Oocyte ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Imaging

AbstractXenopus laevis oocytes are an interesting model for the study of many developmental mechanisms because of their dimensions and the ease with which they can be manipulated. In addition, they are widely employed systems for the expression and functional study of heterologous proteins, which can be expressed with high efficiency on their plasma membrane. Here we applied atomic force microscopy (AFM) to the study of the plasma membrane of X. laevis oocytes. In particular, we developed and optimized a new sample preparation protocol, based on the purification of plasma membranes by ultracentrifugation on a sucrose gradient, to perform a high-resolution AFM imaging of X. laevis oocyte plasma membrane in physiological-like conditions. Reproducible AFM topographs allowed visualization and dimensional characterization of membrane patches, whose height corresponds to a single lipid bilayer, as well as the presence of nanometer structures embedded in the plasma membrane and identified as native membrane proteins. The described method appears to be an applicable tool for performing high-resolution AFM imaging of X. laevis oocyte plasma membrane in a physiological-like environment, thus opening promising perspectives for studying in situ cloned membrane proteins of relevant biomedical/pharmacological interest expressed in this biological system.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

High-Resolution Frequency-Modulation Atomic Force Microscopy in Liquids Using Electrostatic Excitation Method

2010 ◽  
Vol 3 (6) ◽  
pp. 065205 ◽  
Author(s):  
Ken-ichi Umeda ◽  
Noriaki Oyabu ◽  
Kei Kobayashi ◽  
Yoshiki Hirata ◽  
Kazumi Matsushige ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Frequency Modulation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Excitation Method
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