Fig. 2: The feasibility of material and spatial constraint strategies.

a Live/Dead staining of SCs cultured on PCL and PCL@MC laminae for 1 and 7 days. b Statistical analysis of the viability staining results for SCs cultured on PCL and PCL@MC membranes (n = 3). c SEM images of Schwann cells (SCs) and fibroblasts (FBs) adhered to PCL and PCL@MC laminae after incubation for 1 day. d Cytoskeletal imaging showing the adhesion of SCs and FBs on PCL and PCL@MC laminae after 1 day of incubation. e Quantitative analysis of SCs and FBs adhered to PCL and PCL@MC laminae after 1 day (n = 3). f Cell Counting Kit-8 assay was conducted to assess the proliferation conditions of SCs on PCL and PCL@MC laminae (n = 3). g The absolute angles of fibroblasts on the surfaces of PCL and PCL@MC laminae were quantified through cytoskeletal staining and analyzed using ImageJ, with mean ± SD (n = 3). h Fabrication process of the cell chips, from engraving the template via lithography to the application of a polydimethylsiloxane mask. i The graph of the culminating cell chip used in the experiment. j. Illustration for the loading of chemotactic serum and the seeding of SCs. k Rhodamine-labeled Phalloidin staining of SCs recorded their migration status through gradient-narrowing geometric spaces with ratios of 4:4, 4:3, 4:2, and 4:1, from the cell channel to the medium channel at 2 h. l Visualization of the trajectories of SCs migrating within different gradient geometric spaces of the chip under serum chemotaxis during 2 h. m, n Trajectory lengths and average speed of SCs migrating within gradient geometric spaces of the chip during 2 h, analyzed using ImageJ. o Finite element analysis was used to simulate the impact of spatial constraints on sciatic nerve regrowth in vivo. The image shows the 15th day. Mean values are shown and error bars represent ± s.d., as analyzed by two-sided Student’s t-test in (b–n). The experiments in (k) were independently repeated at least three times with similar results.