Fig 2: Morphological and mechanical characterization of the tubular biofunctionalized scaffolds: (a) Electrospun tubular scaffolds were fabricated with a length of 110 mm, an inner diameter of 5 mm, and a thickness of 0.40 ± 0.06 mm. (b) SEM images of control and biofunctionalized scaffolds: Scaffolds coated with FN show a network-like structure on the fibers. Aggregates deposited on the FN + DCN-coated samples are indicated by white arrows. (c,d) The coating of FN, DCN, or FN + DCN in combination was confirmed with IF staining: FN (red) and DCN (green). The white arrows indicate aggregates deposited on the FN + DCN-coated samples. Two-tailed t-test vs. control, n = 3, RPI = relative pixel intensity. (e) Fiber and pore size analysis shows no significant difference between the biofunctionalized scaffolds and the controls. Mechanical properties are not influenced by the protein coating. One-way ANOVA, n = 4, p < 0.05 vs. control.

Fig 3: Static cell culture experiments of vECs on FN- and DCN-coated scaffolds: (a) Attachment and proliferation of vECs after 1, 4, and 7 days. vECs on FN and FN + DCN coating show a significantly higher proliferation rate compared with cells gown on DCN coating or control scaffolds. Two-tailed t-test, compared with control samples, n = 3, n.s. = not significant. (b) SEM images and (c) IF staining of vECs 7 days after seeding on ECM-coated scaffolds. Cells on FN and FN + DCN coating show a spread morphology in contrast with cells on DCN coating and control samples. (d) Semiquantitative fluorescence intensity analysis (relative pixel intensity (a.u.)) of cells on FN and FN + DCN coating shows no significant difference for PECAM-1, vWF, vinculin, or VE-cadherin expression. Two-tailed t-test, n = 5, n.s. = not significant.

Fig 4: High-confidence interaction among extracellular matrix (ECM)–related proteins and greater fibrosis in adult dilated cardiomyopathy (DCM) hearts compared with pediatric DCM hearts. A, STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) analysis shows high-confidence interaction clusters (k-means=5 clusters indicated by node color) formed by ECM-related proteins. B through D, Representative images of Picrosirius Red (PSR) (B) and Masson trichrome–stained (C) left ventricular free wall from pediatric and adult control and DCM myocardium. Scale bar: 100 µm. D, Averaged quantification of collagen content (from PSR-stained sections) in indicated groups (mean±SEM). n=6 hearts per group. *P<0.05 compared with the corresponding control, † P<0.05 compared with the corresponding pediatric group. ADAM indicates a disintegrin and metalloprotease; ADAMTS, a disintegrin and metalloproteinase with thrombospondin motifs; AFU, arbitrary fluorescence units; BGN, biglycan; COL, collagen; DCN, decorin; LUM, lumican; MMP, matrix metalloprotease; NFC, nonfailing control; OGN, osteoglycan; SGCG, sarcoglycan gamma; SPARC, secreted protein acidic and cysteine-rich; THBS1, thrombosondin-1; TIMP, tissue inhibitors of metalloprotease; TNXB, tenascin x; VCAN, versican.

Fig 5: In vitro simulation of in vivo processes: ECFC attraction under dynamic conditions. (a) ECFCs were seeded into tubular constructs and cultured for 24 h on a roller mixer. (b) Adherent cells after 24 h on control scaffolds and on DCN-, FN-, and FN + DCN-coated scaffolds. FN + DCN coating shows a significantly higher cell number when compared with DCN coating and controls. One-way ANOVA, n = 4. (c) PECAM-1 (green), vWF (red), and F-actin (yellow) expression in ECFCs. Cells on FN and FN + DCN show a more spread morphology in contrast to the DCN and control samples.