fibronectin immunofluorescence signal  (Oxford Instruments)

Journal: bioRxiv

Article Title: A human synovial tendon-on-a-chip models key features of peritendinous adhesions and offers a new approach methodology for testing anti-fibrotic drugs

doi: 10.64898/2026.04.03.716316

Figure Lengend Snippet: a-d , Confocal reconstructions of synToC devices cultured without TGF-β1 showing side (left) and top (right) views (SG = synovial gel, T = tendon gel). Devices were stained for collagen III (green) and fibronectin (yellow), with Hoechst (blue) and F-actin (red) as counterstains. The macroscopic device image specifies the location of the confocal image field of view at the synovial-tendon interface. a,b, In -FLS devices, fibroblast migration into the synovial gel is observed, but fibronectin networks remain largely compartmentalized with minimal matrix continuity between the synovial and tendon gels. c,d, In +FLS devices, dense fibronectin- and collagen III-rich networks bridge the synovial and tendon compartments, forming direct matrix extensions characteristic of adhesion-like contacts. Insets highlight synovial-tendon interface regions with a white dashed line. e-h, Confocal images of +TGF-β1 devices at Day 5. Fibronectin-rich interfacial contacts develop in both -FLS and +FLS conditions; however, collagen III deposition within the synovial gel is markedly enriched in +FLS constructs. i, Quantification of collagen III immunofluorescence expression in the synovial and tendon gels, reported as the number of collagen III+ cells mm -3 . Data are mean ± s.d. (n = 4 devices per condition); unpaired t-test; *p<0.05, **p<0.01, ***p<0.001. j, Quantification of adhesion contact length, measured as the length of fibronectin signal that contacts both the synovial and tendon gels, parallel to the tendon long axis. Data are mean ± s.d. (n = 4 devices per condition); unpaired t-test; two-way ANOVA with Tukey’s post-hoc test; *p<0.05, ****p<0.0001.

Article Snippet: A Surface was generated for fibronectin immunofluorescence signal in Imaris.

Techniques: Cell Culture, Staining, Migration, Construct, Immunofluorescence, Expressing

Journal: bioRxiv

Article Title: A human synovial tendon-on-a-chip models key features of peritendinous adhesions and offers a new approach methodology for testing anti-fibrotic drugs

doi: 10.64898/2026.04.03.716316

Figure Lengend Snippet: Tocilizumab and tofacitinib attenuate synovial JAK/STAT activation, collagen III deposition, and fibronectin-mediated synovial-tendon adhesions. a, Drug treatment strategy and experimental timeline for the synToC drug testing scheme, outlining the mechanisms and timing of tocilizumab (TCZ) and tofacitinib (TOFA) dosing. b, Nuclear pSTAT3 expression in the synovial gel, with c, quantification demonstrating a significant reduction in pSTAT3 immunofluorescence with TOFA treatment. d, Quantification and representative images of tendon hydrogel contraction from Days 0-5, plotted as the percent of original hydrogel area. t-test at each time point: n=4 devices, *p<0.05. e, Monocyte transmigration at Day 2, reported as the number of monocytes transmigrated per unit volume. f, Secreted cytokine levels measured from Day 5 supernatants sampled from the apical (vascular) and basal (tendon) compartments. One-way ANOVA with Tukey’s post-hoc test: n=4 devices per condition, *p<0.05, **p<0.01, ***p<0.001. g, Immunofluorescent confocal images at Day 5 of synToC culture, with collagen III (green), Hoechst (blue), and F-actin (red). Images compare an untreated control group to TCZ and TOFA treatments. Quantification of the number of collagen III+ cells in the h, synovial gel (SG) and i, tendon (T). TCZ significantly attenuated collagen III expression in the synovial gel, while both treatments significantly decreased collagen III expression in the tendon. One-way ANOVA with Tukey’s post-hoc test: n=8 devices per condition, **p<0.01. j, Confocal image reconstructions of Day 5 synToC devices, showing a top-down view (top row) and a side view (bottom row). Devices were stained for fibronectin (yellow), Hoechst (blue), and F-actin (red) to compare fibronectin adhesion contacts between untreated and treated devices at Day 5. k, Quantification of adhesion contact length. Both TCZ and TOFA treatment significantly reduced the formation of fibronectin contacts between the synovial and tendon gels. One-way ANOVA with Tukey’s post-hoc test: n=12 devices per condition, **p<0.01, ***p<0.001. l, Total cell density in the synovial gel, reported as the number of cells/mm 3 . Untreated synToC devices had a significantly greater number of cells in the synovial gel compared to drug-treated devices. One-way ANOVA with Tukey’s post-hoc test: n=5 devices per condition, **p<0.01, ***p<0.001.

Article Snippet: A Surface was generated for fibronectin immunofluorescence signal in Imaris.

Techniques: Activation Assay, Expressing, Immunofluorescence, Transmigration Assay, Control, Staining