Fig. 1: Microparticle-conjugated GFP and cell-deposited fibronectin-GFP ligands activate reporter transgenes via synNotch in receiver fibroblasts.

A Left: Schematic of GFP conjugation to microparticles and co-culture with receiver fibroblasts with anti-GFP/tTa synNotch that activates mCherry. Right: Fluorescence microscopy image of receiver fibroblast activated by GFP microparticles. B Fluorescence microscopy images of receiver fibroblasts cultured with 5 μm microparticles conjugated with 0, 100, and 1000 μg/mL of GFP or GFP-sender cells for 1 day. Scale bars, 100 μm. C Percent of mCherry-expressing receiver fibroblasts quantified by image analysis following 24-h co-culture with GFP microparticles or GFP-sender cells. Data represent mean ± s.d. From left to right, n = 5, 2, 4, 3, 3, 5, 3 biological replicates. p = 0.0012(**), p = 0.0003(***), p < 0.0001(****) determined via one-way ANOVA and Tukey’s test. D Schematic of fibroblasts with miRFP nuclear tag producing fibronectin-GFP (FN-GFP) co-cultured with anti-GFP/tTa snyNotch receiver fibroblasts that activate mCherry and constitutively express BFP. E Fluorescence microscopy images of FN-GFP senders and receiver fibroblasts co-cultured for 3 days. Scale bars, 100 μm. The experiment was performed three times with similar results. F Schematic of FN-GFP deposition by FN-GFP-sender cells, decellularization, and reseeding with receiver fibroblasts. G Top row: Schematics of decellularized extracellular matrix (ECM). FN is produced by parental fibroblasts (FN parental) and/or FN-GFP senders cultured at different ratios (1:0, 1:1, or 0:1) for 8 days prior to decellularization. Bottom: Fluorescence microscopy images of receiver fibroblasts cultured for 2 days on corresponding decellularized ECM. Scale bars, 100 μm. H Flow cytometry quantification of mCherry expression in receiver fibroblasts cultured for 2 days on decellularized ECM prepared by FN-parentals and/or FN-GFP fibroblasts. Data represent the distribution of individual cell intensity and median value from n = 1 biological replicate. The experiment was performed three times with similar results. Source data are provided as a Source Data file.