Heterogeneous Structural Color Microfibers for Cardiomyocytes Tug-of-War

Cellular mechanics are of great significance in biological functions and have stimulated the development of various techniques to detect and analyze it. Here, a novel heterogeneous structural color microfiber designed for dynamic cardiac mechanics sensing is presented. The microfiber is fabricated by the programmed injection microfluidic spinning method, which achieves the alternative injection of different solutions and generates axial heterogeneous components. This microfiber contains non-close-packed colloidal arrays for quantitative optical sensing and bioactive methacrylated gelatin (GelMA) for cardiac culture. When the cultivated cardiomyocytes recover autonomous beating cycles, the structural color section would be stretch and exhibits synchronous stretch cycles with dynamic color variation and wavelength shifts, which transforms microcosmic cell-generated force into macroscopic optical signals. In addition, the single-cell-level mechanics detecting platform can be achieved by tuning the size and diameter of the heterogeneous structural color microfibers. These features contribute to the heterogeneous structural color microfiber to be an ideal platform for biomedical fields.