Fig 2: Comparison of CD31 vessel quantity. CD31 vessel quantity in the normal (a), STSG (b), FTSG (c), Matriderm® (d), and AlloDerm® (e) groups, respectively; 100x magnification, 100 µm scale bar; immunostaining technique; Hyperactive fibroblasts in hypertrophic scars secrete higher than normal levels of angiogenic factors, which promote endothelial cell proliferation and more microvessel formation. CD31 helps to promote vascular barrier function in response to inflammatory stimuli. There was a significant increase in vessel quantity expressing CD31 in the FTSG and Matriderm® groups compared to the normal group.

Fig 3: Identification of ECs in remodeling 3DVGs grafted in carotid.(A and B) UMAP plot of EC showing five distinct subtypes colored by cluster. (C) Heatmap showing the differentially expressed genes in the five EC clusters. (D and E) Violin plots for expression of marker genes (CD34 and CD93) in the five EC clusters. (F and G) Representative immunofluorescent costaining of CD93 and CD31 in neoarteries at 2 and 12 weeks postoperatively. (H and I) Representative images showed immunofluorescent en face staining (CD93 and CD31) for neoarteries at 2 and 12 weeks postoperatively. CD93, green; CD31, red; 4',6-diamidino-2-phenylindole (DAPI), blue. (J) Quantitative analysis of CD93+ cells from immunofluorescent en face staining. Plotted data represent means ± SD. For (J), significance was determined by Student’s t test. ns, P > 0.05 and *P < 0.05.

Fig 4: The differentiation of CD34+ cells into CD31+ cells during host remodeling.(A, C, and E) Immunofluorescence staining of midpoint cross sections from neoarteries (left: CD34, red; right: CD31, red). (B, D, and F) Immunofluorescence staining of en face from different regions at different time point samples (CD31, red). (G) Quantitative analysis of CD34- or CD31-positive cells per field (n = 5 independent samples). (H) Comparison of the endothelialization of different sites in neoarteries (n = 3 independent samples). The yellow dotted line marked the anastomosis. Plotted data represent means ± SD.

Fig 5: Assessment of angiogenesis. Immunohistochemistry was performed to stain for CD31+ microvessels within the femoral head. a Representative images of each treatment group are shown. b Within the subchondral bone, the bone surrounding the bone tunnel area, and within the bone tunnel area, the PGK-PDGF-BB-MSC group demonstrated a significantly greater number of CD31+ microvessels than the other treatment groups (P < 0.01 for all). Scale bar: 100 µm. CD31, cluster of differentiation 31; CD core decompression, HG hydrogel, MSC mesenchymal stromal cell, PGK-PDGF-BB-MSC genetically modified phosphoglycerate kinase promoter platelet-derived growth factor-BB over-expressing MSC. **P < 0.01, ***P < 0.001, ****P < 0.0001