scholarly journals Nanoscale Surface Topography Modulates hIAPP Aggregation Pathways at Solid–Liquid Interfaces

2021 ◽  
Vol 22 (10) ◽  
pp. 5142
Author(s):  
Marcel Hanke ◽  
Yu Yang ◽  
Yuxin Ji ◽  
Guido Grundmeier ◽  
Adrian Keller
Keyword(s):  
Surface Topography ◽  
Amyloid Fibrils ◽  
Silicon Oxide ◽  
Ion Beam ◽  
Peptide Hormone ◽  
Time Lapse ◽  
Liquid Interfaces ◽  
Ripple Patterns ◽  
Amorphous Aggregation ◽  
Solid Liquid

The effects that solid–liquid interfaces exert on the aggregation of proteins and peptides are of high relevance for various fields of basic and applied research, ranging from molecular biology and biomedicine to nanotechnology. While the influence of surface chemistry has received a lot of attention in this context, the role of surface topography has mostly been neglected so far. In this work, therefore, we investigate the aggregation of the type 2 diabetes-associated peptide hormone hIAPP in contact with flat and nanopatterned silicon oxide surfaces. The nanopatterned surfaces are produced by ion beam irradiation, resulting in well-defined anisotropic ripple patterns with heights and periodicities of about 1.5 and 30 nm, respectively. Using time-lapse atomic force microscopy, the morphology of the hIAPP aggregates is characterized quantitatively. Aggregation results in both amorphous aggregates and amyloid fibrils, with the presence of the nanopatterns leading to retarded fibrillization and stronger amorphous aggregation. This is attributed to structural differences in the amorphous aggregates formed at the nanopatterned surface, which result in a lower propensity for nucleating amyloid fibrillization. Our results demonstrate that nanoscale surface topography may modulate peptide and protein aggregation pathways in complex and intricate ways.

Site-Specific Preparation of Intact Solid–Liquid Interfaces by Label-Free In Situ Localization and Cryo-Focused Ion Beam Lift-Out

2016 ◽  
Vol 22 (6) ◽  
pp. 1338-1349 ◽  
Author(s):  
Michael J. Zachman ◽  
Emily Asenath-Smith ◽  
Lara A. Estroff ◽  
Lena F. Kourkoutis
Keyword(s):  
Electron Microscopy ◽  
Chemical Analysis ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Milling Process ◽  
Atomic Scale ◽  
Liquid Interfaces ◽  
Label Free ◽  
Solid Liquid

AbstractScanning transmission electron microscopy (STEM) allows atomic scale characterization of solid–solid interfaces, but has seen limited applications to solid–liquid interfaces due to the volatility of liquids in the microscope vacuum. Although cryo-electron microscopy is routinely used to characterize hydrated samples stabilized by rapid freezing, sample thinning is required to access the internal interfaces of thicker specimens. Here, we adapt cryo-focused ion beam (FIB) “lift-out,” a technique recently developed for biological specimens, to prepare intact internal solid–liquid interfaces for high-resolution structural and chemical analysis by cryo-STEM. To guide the milling process we introduce a label-free in situ method of localizing subsurface structures in suitable materials by energy dispersive X-ray spectroscopy (EDX). Monte Carlo simulations are performed to evaluate the depth-probing capability of the technique, and show good qualitative agreement with experiment. We also detail procedures to produce homogeneously thin lamellae, which enable nanoscale structural, elemental, and chemical analysis of intact solid–liquid interfaces by analytical cryo-STEM. This work demonstrates the potential of cryo-FIB lift-out and cryo-STEM for understanding physical and chemical processes at solid–liquid interfaces.

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

scholarly journals Constructing Large 2D Lattices Out of DNA-Tiles

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1502
Author(s):  
Johannes M. Parikka ◽  
Karolina Sokołowska ◽  
Nemanja Markešević ◽  
J. Jussi Toppari
Keyword(s):  
Self Assembly ◽  
Dna Nanotechnology ◽  
Building Blocks ◽  
High Yield ◽  
Dna Nanostructures ◽  
Liquid Interfaces ◽  
Basic Principles ◽  
Dna Tiles ◽  
One Step ◽  
Solid Liquid

The predictable nature of deoxyribonucleic acid (DNA) interactions enables assembly of DNA into almost any arbitrary shape with programmable features of nanometer precision. The recent progress of DNA nanotechnology has allowed production of an even wider gamut of possible shapes with high-yield and error-free assembly processes. Most of these structures are, however, limited in size to a nanometer scale. To overcome this limitation, a plethora of studies has been carried out to form larger structures using DNA assemblies as building blocks or tiles. Therefore, DNA tiles have become one of the most widely used building blocks for engineering large, intricate structures with nanometer precision. To create even larger assemblies with highly organized patterns, scientists have developed a variety of structural design principles and assembly methods. This review first summarizes currently available DNA tile toolboxes and the basic principles of lattice formation and hierarchical self-assembly using DNA tiles. Special emphasis is given to the forces involved in the assembly process in liquid-liquid and at solid-liquid interfaces, and how to master them to reach the optimum balance between the involved interactions for successful self-assembly. In addition, we focus on the recent approaches that have shown great potential for the controlled immobilization and positioning of DNA nanostructures on different surfaces. The ability to position DNA objects in a controllable manner on technologically relevant surfaces is one step forward towards the integration of DNA-based materials into nanoelectronic and sensor devices.

Bridging the Gap between the Nanostructural Organization and Macroscopic Interfacial Rheology of Amyloid Fibrils at Liquid Interfaces

Langmuir ◽  
2014 ◽  
Vol 30 (33) ◽  
pp. 10090-10097 ◽  
Author(s):  
Sophia Jordens ◽  
Patrick A. Rühs ◽  
Christine Sieber ◽  
Lucio Isa ◽  
Peter Fischer ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Interfacial Rheology ◽  
Liquid Interfaces ◽  
Nanostructural Organization
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