Structural Insights into the Mechanism of Heat‐Set Gel Formation of Polyisocyanopeptide Polymers

Gavrilov, Mikhail; Gilbert, Elliot P.; Rowan, Alan E.; Lauko, Jan; Yakubov, Gleb E.

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.

Citation

Gavrilov, M., Gilbert, E. P., Rowan, A. E., Lauko, J., & Yakubov, G. E. (2020). Structural Insights into the Mechanism of Heat‐Set Gel Formation of Polyisocyanopeptide Polymers. Macromolecular Rapid Communications, 41(18), Article 2000304. https://doi.org/10.1002/marc.202000304

• Journal Article Type: Article
• Acceptance Date: Jul 28, 2020
• Online Publication Date: Aug 6, 2020
• Publication Date: 2020-09
• Deposit Date: Aug 30, 2020
• Publicly Available Date: Aug 7, 2021
• Journal: Macromolecular Rapid Communications
• Print ISSN: 1022-1336
• Electronic ISSN: 1521-3927
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 41
• Issue: 18
• Article Number: 2000304
• DOI: https://doi.org/10.1002/marc.202000304
• Keywords: Organic Chemistry; Materials Chemistry; Polymers and Plastics
• Public URL: https://nottingham-repository.worktribe.com/output/4816708
• Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/marc.202000304
• Additional Information: This is the peer reviewed version of the following article: Gavrilov, M., Gilbert, E. P., Rowan, A. E., Lauko, J., Yakubov*, * G. E., Structural Insights into the Mechanism of Heat‐Set Gel Formation of Polyisocyanopeptide Polymers. Macromol. Rapid Commun. 2020, 2000304., which has been published in final form at https://doi.org/10.1002/marc.202000304. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.