Non-invasively visualizing cell-matrix interactions in two-photon excited supramolecular hydrogels

Visualizing the role of extracellular matrix (ECM) in cell bioactivities in three-dimensional (3D) view is highly important for in-depth understanding of fundamental physiological issues in various in vitro experiments. Using current designs it is difficult to produce 3D biomimetic ECM with intrinsic fluorescence under non-invasive near-infrared excitation. Herein, we have designed and synthesized a series of non-conventional coumarin-derived hydrogelators, which can self-assemble to form nanofibrous 3D supramolecular hydrogels through C-H. . .O bonds and be excited by two-photon absorption, ensuring the direct and dynamic visualization of cell-matrix interactions with high resolution images in a 3D environment. Real-time monitoring of ECM-regulated dynamic cell behaviours is highly desirable for future basic and applied research.