An affordable and tunable continuous wrinkle micropattern for cell physical guidance study

Geometrical cues in the extracellular environment are essential for cells guiding. Conventional fabrications for well-defined microstructures are usually associated with expensive and time-consuming micro-electro-mechanical systems (MEMS), including lithography and etching. Additionally, the microstructures produced on silicon wafers are not amendable after molding, hindering the applicability. Here, we developed a low-cost and efficient fabrication process to generate highly ordered microstructures for cell culture by designing and fabricating a tunable wrinkled on biocompatible polydimethylsiloxane (PDMS) surfaces based on different mechanical properties of the biomaterials. The mechanical properties, including Young's modulus, tensile strength, and thickness ratio between the stiff and soft bilayers, can be determined by the thickness of PDMS film, curing temperature, UV exposure time, applied strain rates during the fabrication, leading to various amplitudes and wavelengths of the wrinkled topography on polymeric materials. Those wrinkled surfaces with micro-pattern are further applied to hCMEC/D cell culture, an immortalized human cerebral microvascular endothelial cell line, to induce cell proliferation and provide guidance for cell arrangement and migration. Therefore, this report sheds light on cell biology and biomedical tissue engineering by delivering an affordable and tunable fabrication process for wrinkles formations on the polymeric thin film.