A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water

In the article “A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water” by Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga and Ali Miserez, a short biomimetic peptide composed of eight amino acid residues derived from squid sucker ring teeth proteins is demonstrated to form hydrogel in water without any cross‐linking agent or chemical modification and exhibits a stiffness on par with the stiffest peptide hydrogels.
Their study broadens the range of secondary structures available to create supramolecular hydrogels, and introduces 310‐helices as transient building blocks for gelation via a 310‐to‐β‐sheet conformational transition.*

The AFM images presented in this study were obtained in soft tapping mode using NanoWorld Pointprobe® NCSTR AFM probes.

Figure 1 from «A Short Peptide Hydrogel with High Stiffness Induced by
310‐ Helices to β‐Sheet Transition in Water” by Shu Hui Hiew et al.
Structural features and physico‐chemical properties of GV8 peptide hydrogel observed with time‐series spectroscopy measurements during gelation
b) AFM amplitude profile of dried GV8 hydrogel with fibers of ≈6–10 nm height.

*Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga, Ali Miserez
A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water
Advanced Science 2019, 1901173
Doi: https://doi.org/10.1002/advs.201901173

Please follow this external link to read the full article: https://onlinelibrary.wiley.com/doi/full/10.1002/advs.201901173

Open Access: The article « A Short Peptide Hydrogel with High Stiffness Induced by 310‐Helices to β‐Sheet Transition in Water » ” by Shu Hui Hiew, Harini Mohanram, Lulu Ning, Jingjing Guo, Antoni Sánchez‐Ferrer, Xiangyan Shi, Konstantin Pervushin, Yuguang Mu, Raffaele Mezzenga and Ali Miserez is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other thirdparty material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy

Real-space images of polymers with sub-molecular resolution could provide valuable insights into the relationship between morphology and functionality of polymer optoelectronic devices, but their acquisition is problematic due to perceived limitations in atomic force microscopy (AFM).*

In the article “Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy” Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton show that individual thiophene units and the lattice of semicrystalline spin-coated films of polythiophenes (PTs) may be resolved using AFM under ambient conditions through the low-amplitude (≤ 1 nm) excitation of higher eigenmodes of a cantilever.*

They authors demonstrate that the use of higher eigenmodes in tapping-mode ambient AFM can be successfully employed to characterize both individual polymer strands down to a single-atom level and also the ordering of a semi-crystalline polymer with technological relevance. The combination of AFM and solution deposition provides a simple and high-resolution approach to characterizing the structure of polymers.*

The use of NanoWorld Arrow-UHF high frequency AFM probes at their first eigenmode of ~1.4 MHz is mentioned.*


Figure 1a from “Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy” by V. Korolkov et al.: High-resolution AFM images of P3DT adsorbed on the surface of hBN. a An overview height scan of P3DT assembled on hBN, scan rate 6.51 Hz, 1024 × 1024 px; inset shows lattice frequency shift image of hBN acquired in FM-AFM tapping mode, scan rate 39 Hz, 512 × 512 px; both images were acquired with the same Arrow UHF probe oscillating at fundamental frequency of 1.42 MHz.

*Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton
Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy
Nature Communications, volume 10, Article number: 1537 (2019)
doi: https://doi.org/10.1038/s41467-019-09571-6

Please follow this external link to read the full article: https://rdcu.be/bLSdL

Open Access: The article « Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy » by Vladimir V. Korolkov, Alex Summerfield, Alanna Murphy, David B. Amabilino, Kenji Watanabe, Takashi Taniguchi and Peter H. Beton is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters

Polydimethylsiloxane (PDMS) is a promising biomaterial for generating artificial extracellular matrix (ECM) like patterned topographies, yet its hydrophobic nature limits its applicability to cell-based approaches.” Although plasma treatment can enhance the wettability of PDMS, the surface is known to recover its hydrophobicity within a few hours after exposure to air. *

To investigate the capability of a novel PDMS-type (X-PDMS) for in vitro based assessment of physiological cell properties, the authors of the article “Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters” cited here, designed and fabricated plane as well as nano- and micrometer-scaled pillar-patterned growth substrates using the elastomer types S-, H- and X-PDMS, which were fabricated from commercially available components.*

To assess their applicability to cell-based approaches, Marina Scharin-Mehlmann et al., characterized the generated surfaces using water contact angle (WCA) measurement and atomic force microscopy (AFM) as indicators of wettability and roughness, respectively.*

The surface roughness of the samples was determined by Atomic Force Microscopy in tapping mode. For plane and flat pillar patterned PDMS (130 and 190 nm nominal pillar height) surfaces, a standard tapping mode AFM probe ( Pointprobe® NCHR, NanoWorld) was used. For patterned surfaces with pillars of 1,800 nm height tilt compensated high-aspect-ratio AFM probes (AR5T-NCHR, NanoWorld) were used. The scanning area was 50 × 50 μm2, the scanning rate 0.5 Hz. In this scanning area each roughness value (root mean square roughness Rq) was evaluated from five 10 × 10 μm2 areas.*

Figure 5 from “Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters” by Marina Scharin-Mehlmann et al.: AFM analysis of structured PDMS substrates. (A) Three-dimensional reconstructions of fabricated pillar-structured PDMS substrates recorded by AFM. (B) Mean pillar height of plane S-, H-, and X-PDMS as measured by AFM. All data are significantly different at a significance level of P ≤ 0.001 as evaluated by two-way ANOVA unless otherwise indicated. Color coding of statistical analysis: within group “130 nm,” purple; within group “190 nm,” pink.

Figure 5 from “Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters” by Marina Scharin-Mehlmann et al.: AFM analysis of structured PDMS substrates. (A) Three-dimensional reconstructions of fabricated pillar-structured PDMS substrates recorded by AFM. (B) Mean pillar height of plane S-, H-, and X-PDMS as measured by AFM. All data are significantly different at a significance level of P ≤ 0.001 as evaluated by two-way ANOVA unless otherwise indicated. Color coding of statistical analysis: within group “130 nm,” purple; within group “190 nm,” pink.

*Marina Scharin-Mehlmann, Aaron Häring, Mathias Rommel, Tobias Dirnecker, Oliver Friedrich, Lothar Frey and Daniel F. Gilbert
Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters
Frontiers in Bioengineering and Biotechnology. 2018; 6: 51
DOI: 10.3389/fbioe.2018.00051

Please follow this external link to view the full article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938557/

Open Access: The article «Nano- and Micro-Patterned S-, H-, and X-PDMS for Cell-Based Applications: Comparison of Wettability, Roughness, and Cell-Derived Parameters» by Marina Scharin-Mehlmann, Aaron Häring, Mathias Rommel, Tobias Dirnecker, Oliver Friedrich, Lothar Frey and Daniel F. Gilbert (2018) is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.