Fig 1.
The 3D architecture and pore size of porous collagen scaffolds.
(A) A 3D collagen scaffold measured to a diameter of 8 mm and a thickness of 2 mm. (B) Representative images captured by scanning electron microscopy on the surface (left) and through a cross section (right) of collagen scaffold.
Table 1.
Mechanical properties of collagen scaffold.
Fig 2.
Capillary formation from human endothelial cells cultured in collagen scaffolds for 3 days.
(A) Human dermal microvascular endothelial cells formed CD31+ capillaries with clear luminal structures at 3 days in culture. (B) A higher magnification of an inset box in (A) with capillary-like structures identified by arrows. Scale bar = 100 μm.
Fig 3.
Vascular infiltration in collagen scaffolds implanted in mice.
(A) Appearance of scaffolds harvested from mice at 1 and 4 weeks. Representative images of scaffold sections stained with haematoxylin and eosin (B) or endothelial cell marker CD31 (C) at 1, 2, 4 and 8 weeks post-implantation. Percentage of vascular volume (D) and percent of remaining collagen scaffold (E) at 1, 2, 4 and 8 weeks post-implantation (n = 3–6 mice). *p<0.05 and **p<0.01 by one-way ANOVA with Turkey post-hoc test. Scale bar = 100 μm.
Fig 4.
Tissue weight, volume and vascularity in tissue constructs generated in rat tissue engineering chambers.
(A) The polyacrylic chambers containing collagen scaffolds infiltrated with fibrinogen gel (circled) or fibrinogen gel alone were placed around the femoral artery and vein in the groin region of rats. Scale bar = 5 mm. (B) Representative photomicrograph of new tissues generated in the tissue engineering chambers contained collagen scaffold infiltrated with fibrinogen gel (left) or fibrinogen gel alone (right) at 4 weeks post-implantation. (C) Representative images of tissue sections stained with blood vessel marker lectin. Top two figures: fibrinogen alone (-scaffold), bottom two figures collagen scaffold with fibrinogen (+scaffold). (D) The absolute vascular volume in vascularized tissues at 4 weeks post-implantation (n = 7). (E) The weight and volume of tissue constructs harvested at 4 weeks post-implantation (n = 7). **p<0.01 by unpaired t-test. Scale bars = 100 μm.
Fig 5.
Morphology and growth of human ASCs cultured in 3D collagen scaffolds over 21 days.
(A) Representative images captured from 3D collagen scaffolds seeded with human ASCs for 24 hours: haematoxylin and eosin (H&E) staining and scanning electron microscopy (SEM). The white arrow demonstrates human ASCs attached to the collagen scaffold. (B) Representative images of GFP-expressed human ASCs cultured in collagen scaffolds for 7 and 21 days. Scale bar = 200 μm. (C) The proliferation rate of GFP-expressed human ASCs cultured in 3D collagen scaffolds and on 2D collagen-coated plates (n = 3). **p<0.01 vs 2D culture by unpaired t-test.
Fig 6.
Tissue constructs engineered in rat tissue engineering chambers containing collagen scaffolds seeded with human ASCs.
(A) The absolute vascular volume in tissue constructs harvested at 2 weeks post-implantation (n = 4). The total weight (B) and volume (C) of chamber tissue constructs harvested at 2 weeks post-implantation (n = 4). Human ASCs were identified by human-specific Ku80 (brown nucleus staining) in (D) the collagen scaffold and (E) the tissue construct harvested at 2 weeks post-implantation. **p<0.01 by unpaired t-test.