Fig. 1: Establishment and evaluation of the SCmic model.

a Workflow for the establishment of the SCmic model by Figdraw, which consists of a cross-linked hydrogel (GMHA), nonviable HaCaT and Sebaceous cells and microbiota. b Photograph of the model surface was taken with an inverted optical microscope (×4) (c) SEM plot of C. acnes biofilm generated after 48 h of incubation on the model. d Partial enlargement of Fig. c shows a large number of biofilms (arrows) in the surface of cells. e C. acnes, S. aureus and S. epidermidis inoculated on the model in different concentrations ranging from 10⁴ to 10⁸ colony-forming units (CFU) mL^-1 and analyzed on days 1, 3, 5 and 7 by PMA-qPCR counting. f 3D reconstruction of confocal laser scanning microscopy (CLSM) images of the growth of bacteria on models with or without dead cells (green for live bacterial/red for dead cells). g 3D reconstructed CLSM Z-stacks of triple species biofilm images containing S. epidermidis, S. aureus and C. acnes. Bacteria were detected by FISH using S. epidermidis-specific (green), S. aureus-specific (red) and C. acnes-specific (orange) probes. SCmic model with a thickness of 20 μm. The heatmap represents the distribution changes of bacteria at different depths. h SCmic model with a thickness of 50 μm. 3D reconstructed CLSM Z-stacks of triple species biofilm images containing S. epidermidis, S. aureus and C. acnes. Bacteria were detected by FISH using S. epidermidis-specific (green), S. aureus-specific (red) and C. acnes-specific (orange) probes. The heatmap represents the distribution changes of bacteria at different depths. All microscopy experiments were performed in triplicate with similar results. Source data are provided as a Source Data file.