Optomechanically Actuated Hydrogel Platform for Cell Stimulation with Spatial and Temporal Resolution

• Type of Material: Article
• Authors: Allison N. Ramey-Ward, Emory University; Yixiao Dong, Emory University; Jin Yang, University of Wisconsin-Madison; Hiroaki Ogasawara, Emory University; Elizabeth C. Bremer-Sai, University of Wisconsin-Madison; Olga Brazhkina, Emory University; Christian Franck, University of Wisconsin-Madison; Michael Davis, Emory University; Khalid Salaita, Emory University
• Language: English
• Date: 2023-09-11
• Publisher: American Chemical Society
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors. Published by American Chemical Society
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): https://doi.org/10.1021%2Facsbiomaterials.3c00516
• Title of Journal or Parent Work: American Chemical Society Biomaterials Science and Engineering
• Volume: 9
• Issue: 9
• Start Page: 5361
• End Page: 5375
• Grant/Funding Information: This work was supported by NIH R01GM131099, RM1GM145394, and R01AI172452. H.O. acknowledges the Naito Foundation and the Uehara Memorial Foundation for their research support.
• Keywords: myogenesis; hydrogel; optomechanical actuator; mechanobiology
• Research Categories: Biology, Cell

Abstract

Cells exist in the body in mechanically dynamic environments, yet the vast majority of in vitro cell culture is conducted on static materials such as plastic dishes and gels. To address this limitation, we report an approach to transition widely used hydrogels into mechanically active substrates by doping optomechanical actuator (OMA) nanoparticles within the polymer matrix. OMAs are composed of gold nanorods surrounded by a thermoresponsive polymer shell that rapidly collapses upon near-infrared (NIR) illumination. As a proof of concept, we crosslinked OMAs into laminin-gelatin hydrogels, generating up to 5 μm deformations triggered by NIR pulsing. This response was tunable by NIR intensity and OMA density within the gel and is generalizable to other hydrogel materials. Hydrogel mechanical stimulation enhanced myogenesis in C2C12 myoblasts as evidenced by ERK signaling, myocyte fusion, and sarcomeric myosin expression. We also demonstrate rescued differentiation in a chronic inflammation model as a result of mechanical stimulation. This work establishes OMA-actuated biomaterials as a powerful tool for in vitro mechanical manipulation with broad applications in the field of mechanobiology.