Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia 30322, United States.
Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States.
ACS Biomater Sci Eng. 2023 Sep 11;9(9):5361-5375. doi: 10.1021/acsbiomaterials.3c00516. Epub 2023 Aug 21.
Cells exist in the body in mechanically dynamic environments, yet the vast majority of 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 mechanical manipulation with broad applications in the field of mechanobiology.
细胞存在于具有机械动态环境的体内，但绝大多数细胞培养都是在塑料盘和凝胶等静态材料上进行的。为了解决这一限制，我们报告了一种方法，通过在聚合物基质中掺杂光机械致动器（OMA）纳米粒子，将广泛使用的水凝胶转变为具有机械活性的基质。OMA 由金纳米棒组成，周围是热响应聚合物壳，当受到近红外（NIR）光照射时，聚合物壳会迅速坍塌。作为概念验证，我们将 OMA 交联到层粘连蛋白-明胶水凝胶中，通过近红外脉冲产生高达 5μm 的变形。这种响应可以通过凝胶中的近红外强度和 OMA 密度进行调节，并且可以推广到其他水凝胶材料。水凝胶的机械刺激增强了 C2C12 成肌细胞的成肌作用，这表现在 ERK 信号、肌细胞融合和肌球蛋白表达上。我们还证明了机械刺激导致慢性炎症模型中分化的恢复。这项工作确立了 OMA 驱动的生物材料作为机械操纵的有力工具，在机械生物学领域具有广泛的应用。
