Direct cell-cell communication with three-dimensional cell morphology on wrinkled microposts

Cell-cell communication plays a critical role in a myriad of processes, such as homeostasis, angiogenesis, and carcinogenesis, in multi-cellular organisms. Monolayer cell models have notably improved our understanding of cellular interactions. However, the cultured cells on the planar surfaces adopt a two-dimensional morphology, which poorly imitates cellular organization in vivo, providing physiologically-irrelevant cell responses. Non-planar surfaces comprising various patterns have demonstrated great abilities in directing cellular growth and producing different cell morphologies. In recent years, a few topographical substrates have provided valuable information about cell-cell signalling, however, none of these studies have reported a three-dimensional (3D) cell morphology. Here, we introduce a structurally tunable topographical platform that can maintain cell coupling while inducing a true 3D cell morphology. Optical imaging and fluorescence recovery after photobleaching are used to illustrate these capabilities. Our analyses suggest that the intercellular signalling on the present platform, which we propose is mainly through gap junctions, is comparable to that in natural tissue. Statement of significance A better understanding of direct cellular communication can help treating neurological diseases and cancers, which may be caused by dysfunctional intercellular signaling. To investigate cell-cell contact, cells are conventionally plated onto planar surfaces, where they flatten and adopt a two-dimensional cell morphology. These unrealistic models are physiologically-irrelevant since cells exhibit a three-dimensional (3D) shape in the body. Therefore, porous scaffolds and topographical surfaces, capable of inducing various cell morphologies, have been introduced, in which the latter is more desirable for sample imaging and screening. However, the few non-planar substrates used to study cell coupling have not produced a 3D cell shape. Here, we present a tunable culture platform that can control direct cell-cell communication while maintaining true 3D cell morphologies.