1
|
Gavrilov M, Gilbert EP, Rowan AE, Lauko J, Yakubov GE. Structural Insights into the Mechanism of Heat-Set Gel Formation of Polyisocyanopeptide Polymers. Macromol Rapid Commun 2020; 41:e2000304. [PMID: 32761855 DOI: 10.1002/marc.202000304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/28/2020] [Indexed: 12/17/2022]
Abstract
One of the key factors influencing the mechanical properties of natural and synthetic extracellular matrices (ECM) is how large-scale 3D gel-like structures emerge from the molecular self-assembly of individual polymers. Here, structural characterization using small-angle neutron scattering (SANS) of ECM-mimicking polyisocyanopeptide (PIC) hydrogels are reported as a function of background ions across the Hofmeister series. More specifically, the process of polymer assembly is examined by probing the structural features of the heat-set gels and correlating them with their rheological and micro-mechanical properties. The molecular parameters obtained from SANS clearly show changes in polymer conformation which map onto the temperature-induced changes in rheological and micro-mechanical behavior. The formation of larger structures are linked to the formation of cross-links (or bundles), whilst the onset of their detection in the SANS is putatively linked to their concentration in the gel. These insights provide support for the 'hot-spot' gelation mechanism of PIC heat-set gels. Finally, it is found that formation of cross-links and heat-set gelling properties can be strongly influenced by ions in accordance with Hofmeister series. In practice, these results have significance since ions are inherently present in high concentration during cell culture studies; this may therefore influence the structure of synthetic ECM networks.
Collapse
Affiliation(s)
- Mikhail Gavrilov
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Elliot P Gilbert
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia.,Australian Institute for Bioengineering and Nanotechnology and Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Alan E Rowan
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jan Lauko
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Gleb E Yakubov
- School of Biosciences, Faculty of Science, University of Nottingham, Nottingham, UK.,School of Chemical Engineering, The University of Queensland, St Lucia, QLD, 4072, Australia
| |
Collapse
|
3
|
Kowoll T, Fritsch-Decker S, Diabaté S, Nienhaus GU, Gerthsen D, Weiss C. Assessment of in vitro particle dosimetry models at the single cell and particle level by scanning electron microscopy. J Nanobiotechnology 2018; 16:100. [PMID: 30526603 PMCID: PMC6284276 DOI: 10.1186/s12951-018-0426-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 11/22/2018] [Indexed: 01/18/2023] Open
Abstract
Background Particokinetic models are important to predict the effective cellular dose, which is key to understanding the interactions of particles with biological systems. For the reliable establishment of dose–response curves in, e.g., the field of pharmacology and toxicology, mostly the In vitro Sedimentation, Diffusion and Dosimetry (ISDD) and Distorted Grid (DG) models have been employed. Here, we used high resolution scanning electron microscopy to quantify deposited numbers of particles on cellular and intercellular surfaces and compare experimental findings with results predicted by the ISDD and DG models. Results Exposure of human lung epithelial A549 cells to various concentrations of differently sized silica particles (100, 200 and 500 nm) revealed a remarkably higher dose deposited on intercellular regions compared to cellular surfaces. The ISDD and DG models correctly predicted the areal densities of particles in the intercellular space when a high adsorption (“stickiness”) to the surface was emulated. In contrast, the lower dose on cells was accurately inferred by the DG model in the case of “non-sticky” boundary conditions. Finally, the presence of cells seemed to enhance particle deposition, as aerial densities on cell-free substrates were clearly reduced. Conclusions Our results further validate the use of particokinetic models but also demonstrate their limitations, specifically, with respect to the spatial distribution of particles on heterogeneous surfaces. Consideration of surface properties with respect to adhesion and desorption should advance modelling approaches to ultimately predict the cellular dose with higher precision. Electronic supplementary material The online version of this article (10.1186/s12951-018-0426-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Thomas Kowoll
- Laboratory for Electron Microscopy, Karlsruhe Institute of Technology (KIT), Campus South, Engesserstr. 7, 76131, Karlsruhe, Germany.
| | - Susanne Fritsch-Decker
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Silvia Diabaté
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.,Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Campus South, Wolfgang-Gaede-Str. 1, 76131, Karlsruhe, Germany.,Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.,Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Dagmar Gerthsen
- Laboratory for Electron Microscopy, Karlsruhe Institute of Technology (KIT), Campus South, Engesserstr. 7, 76131, Karlsruhe, Germany
| | - Carsten Weiss
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
4
|
Iberi V, Liang L, Ievlev AV, Stanford MG, Lin MW, Li X, Mahjouri-Samani M, Jesse S, Sumpter BG, Kalinin SV, Joy DC, Xiao K, Belianinov A, Ovchinnikova OS. Nanoforging Single Layer MoSe2 Through Defect Engineering with Focused Helium Ion Beams. Sci Rep 2016; 6:30481. [PMID: 27480346 PMCID: PMC4969618 DOI: 10.1038/srep30481] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/04/2016] [Indexed: 11/09/2022] Open
Abstract
Development of devices and structures based on the layered 2D materials critically hinges on the capability to induce, control, and tailor the electronic, transport, and optoelectronic properties via defect engineering, much like doping strategies have enabled semiconductor electronics and forging enabled introduction the of iron age. Here, we demonstrate the use of a scanning helium ion microscope (HIM) for tailoring the functionality of single layer MoSe2 locally, and decipher associated mechanisms at the atomic level. We demonstrate He(+) beam bombardment that locally creates vacancies, shifts the Fermi energy landscape and increases the Young's modulus of elasticity. Furthermore, we observe for the first time, an increase in the B-exciton photoluminescence signal from the nanoforged regions at the room temperature. The approach for precise defect engineering demonstrated here opens opportunities for creating functional 2D optoelectronic devices with a wide range of customizable properties that include operating in the visible region.
Collapse
Affiliation(s)
- Vighter Iberi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
- The Procter and Gamble Company Winton Hill Business Center (WBHC), Cincinnati, OH 45224, USA
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Anton V. Ievlev
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37931, USA
| | - Michael G. Stanford
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Ming-Wei Lin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Xufan Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Masoud Mahjouri-Samani
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37931, USA
| | - Bobby G. Sumpter
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37931, USA
- Computer Science & Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sergei V. Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37931, USA
| | - David C. Joy
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Alex Belianinov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Procter and Gamble Company Winton Hill Business Center (WBHC), Cincinnati, OH 45224, USA
| | - Olga S. Ovchinnikova
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37931, USA
| |
Collapse
|