Hydrogels are promising soft materials as tissue engineering scaffolds, stretchable sensors, and soft robotics. *
Yet, it remains challenging to develop synthetic hydrogels with mechanical stability and durability similar to those of the connective tissues. Many of the necessary mechanical properties, such as high strength, high toughness, rapid recovery, and high fatigue resistance, generally cannot be established together using conventional polymer networks. *
In the article “Strong, tough, rapid-recovery, and fatigue-resistant hydrogels made of picot peptide fibres” Bin Xue, Zoobia Bashir, Yachong Guo, Wenting Yu, Wenxu Sun, Yiran Li, Yiyang Zhang, Meng Qin, Wei Wang and Yi Cao present a type of hydrogels comprising hierarchical structures of picot fibres made of copper-bound self-assembling peptide strands with zipped flexible hidden length. *
The redundant hidden lengths allow the fibres to be extended to dissipate mechanical load without reducing network connectivity, making the hydrogels robust against damage. *
The hydrogels possess high strength, good toughness, high fatigue threshold, and rapid recovery, comparable to or even outperforming those of articular cartilage. *
The study by Bin Xue et al. highlights the importance of tailoring hydrogel network structures at the molecular level to achieve uncharted mechanical performance. It is possible to further improve the mechanical properties by using different self-assembling peptides or synthetic motifs. *
The authors of the article anticipate that the engineered hydrogels demonstrated in this study may find broad applications as tissue engineering scaffolds, stretchable sensors, and components of soft robotics. *
NANOSENSORS™ PointProbe® Plus PPP-SEIHR AFM probes for soft tapping (typical resonant frequency 130 kHz, typical force constant 15 N/m) were used to characterize the supramolecular and picot GK11 peptide fibres without and with metal Cu2+ coordination by Atomic Force Microscopy. *
The point stiffness was determined as the normal force divided by the deformation of the sample and calculated from the force-displacement curves. For each sample, more than six regions were randomly selected to perform the nanoindentation. At least three AFM cantilevers were used in the experiments to exclude a tip dependency on the results. *
Fig. 2 from Bin Xue et al. “Strong, tough, rapid-recovery, and fatigue-resistant hydrogels made of picot peptide fibres”:
Characterisation of supramolecular and picot GK11 peptide fibres without and with metal Cu2+ coordination.
a AFM images of the fibres formed by the self-assembly of GK11 in the absence (top) and presence (bottom) of Cu2+. The graphs below the images correspond to the diameter distributions of the fibres. Scale bar = 1 μm. b, c CD spectrum (b) and FT-IR spectroscopy (c) of the self-assembled GK11 peptide with (GK11/Cu2+) and without Cu2+ (GK11). d As for (a), but for picot fibres (top) and metal ion-clad picot fibres (bottom) formed by GK11 linked with polyacrylamide in the absence and presence of Cu2+. Scale bar = 1 μm.
*Bin Xue, Zoobia Bashir, Yachong Guo, Wenting Yu, Wenxu Sun, Yiran Li, Yiyang Zhang, Meng Qin, Wei Wang and Yi Cao
Strong, tough, rapid-recovery, and fatigue-resistant hydrogels made of picot peptide fibres
Nature Communications volume 14, Article number: 2583 (2023)
DOI: https://doi.org/10.1038/s41467-023-38280-4
Please follow this external link to read the full article https://rdcu.be/dhUKb
Open Access: The article “Strong, tough, rapid-recovery, and fatigue-resistant hydrogels made of picot peptide fibres” by Bin Xue, Zoobia Bashir, Yachong Guo, Wenting Yu, Wenxu Sun, Yiran Li, Yiyang Zhang, Meng Qin, Wei Wang and Yi Cao 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 licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence 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 licence, visit https://creativecommons.org/licenses/by/4.0/.