In vivo engineering of organs: The bone bioreactor

Stevens et al. 10.1073/pnas.0504705102.

Supporting Information

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Supporting Figure 5
Supporting Figure 6
Supporting Figure 7
Supporting Text
Supporting Figure 8
Supporting Figure 9

Supporting Figure 5

Fig. 5. Histological characterization of the vascular canals within the bioreactor. Hematoxylin/eosin- (H&E) stained cross section of the bone bioreactor in absence of growth factors after 14 days. (Bar, 100 mm.)

Supporting Figure 6

Fig. 6. H&E-stained cross section of the bone bioreactor and adjacent cortical bone demonstrating new bone >1.5-mm thick. Arrowheads indicate demarcation between bioreactor space (Left) and cortical bone (Right) (Bar, 500 mm.)

Supporting Figure 7

Fig. 7. Typical compressive stress vs. strain curve for a machined specimen of engineered bone harvested from the bioreactor space after 6 weeks. We observed that the failure in the bone occurred as a prolonged disintegration rather than a sudden event, because the failure due to fracture in compression involves the shearing of surfaces past each other.

Supporting Figure 8

Fig. 8. Histological analysis of donor site after harvest of neo-bone from the bone bioreactor. H&E-stained cross section of the cortical bone of the tibia 6 weeks postharvest (Bar, 200 mm.) The normal structure of the tibia is uncompromised after the harvest.

Supporting Figure 9

Fig. 9. Surgical approach to the creation of a bone bioreactor (subperiosteal space) in human tibia. (A) Bent 21-gauge needle inserted between the cambium and the subjacent bone at the anteromedial side of the tibia and minimally invasive creation of bioreactor space. Arrowhead indicates the point at which the needle is introduced under the cambium. (B and C) Injection of gel containing methylene blue dye into the subperiosteal space. Arrowhead points to the elevation of periosteum by injected gel. (D) Dissection of created subperiosteal space. (E) Higher-magnification image of the subperiosteal bioreactor space after dissection and peeling back of the periosteum. Note: A layer of gel up to 1-cm thick is located between the cambium layer of the periosteum and the bone. Five fresh-frozen human cadaver legs were utilized.

Supporting Text

Machined samples were used to determine the apparent density of the engineered bone and compact bone from the tibia (n = 10). We found no significant difference between the apparent density of the engineered bone [1.77 ± 0.16 g·cm^-3 (n = 10)] and of rabbit compact bone as measured here [1.84 ± 0.06 g·cm^-3 (n = 10)]. Tissue densities of compact bone reported in the literature range from 1.6 to 2.0 g·cm^-3, with a value of »1.8 g·cm^-3 for human compact bone.