Three-dimensional co-cultures of osteoblasts and endothelial cells in DegraPol foam: histological and high-field magnetic resonance imaging analyses of pre-engineered capillary networks in bone grafts.

Tissue engineering of bone grafts was addressed in a critical-sized model on the chick chorioallantoic membrane model, using DegraPol(®) foam as scaffold material. The scaffolds were seeded with cultures of human osteoblasts and human endothelial cells, respectively, or with a co-culture of the two cell types (control: no cells). In vitro samples (7 days cultivation) and ex vivo chorioallantoic membrane model samples at incubation day 15 were analyzed by high-field magnetic resonance imaging (MRI) and histology. The co-culture system performed best with respect to perfusion, as assessed by contrast-enhanced MRI using gadolinium-diethylene-triamine-pentaacetic acid (DTPA). The scaffold seeded by the co-culture supported an increased vascular ingrowth, which was confirmed by histological analysis. DegraPol foam is a suitable scaffold for bone tissue engineering and the MRI technique allows for nondestructive and quantitative assessment of perfusion capability during early stages of bone forming constructs.