Fig. 4

Incorporation and vascularization of implanted scaffolds. a-d HE-stained sections of SVF- (a, b) and ad-MVF-seeded (c, d) Integra® scaffolds on day 14 after implantation into full-thickness skin defects within dorsal skinfold chambers of C57BL/6 recipient mice (broken lines = implant; closed frames = center zones of the implants; b, d = higher magnifications of closed frames in a and c arrows = nuclei of individual cells). Scale bars: a, c = 260 μm; b, d = 40 μm. e-g Polarized light microscopy of Sirius red-stained sections of normal skin (e) as well as SVF- (f) and ad-MVF-seeded (g) Integra® scaffolds. Scale bars: 25 μm. h Total collagen ratio in the border and center zones of SVF- (white bars, n = 8) and ad-MVF-seeded (black bars, n = 8) Integra® scaffolds on day 14 after implantation, as assessed by histology. Means ± SEM. i-l Immunohistochemical detection of CD31⁺ microvessels (arrows) within the border (i, j) and center (k, l) zones of SVF- (i, k) and ad-MVF-seeded (j, l) Integra® scaffolds. Scale bars: 25 μm. m Microvessel density in the border and center zones of SVF- (white bars, n = 8) and ad-MVF-seeded (black bars, n = 8) Integra® scaffolds on day 14 after implantation, as assessed by immunohistochemistry. Means ± SEM. *p < 0.05 vs. SVF-seeded Integra® scaffolds. n-p Representative immunohistochemical staining of CD31⁺/GFP⁺ microvessels (arrows) and CD31⁺/GFP⁻ microvessels (arrowheads) within the border zone of a SVF-seeded Integra® scaffold on day 14 after implantation. Scale bars: 55 μm. q CD31⁺/GFP⁺ microvessels in the border and center zones of SVF- (white bars, n = 8) and ad-MVF-seeded (black bars, n = 8) Integra® scaffolds on day 14 after implantation, as assessed by immunohistochemistry. Means ± SEM. *p < 0.05 vs. SVF-seeded Integra® scaffolds