Dynamic Gd-DTPA Enhanced MRI as a Surrogate Marker of Angiogenesis in Tissue-engineered Rabbit Calvarial Constructs: A Pilot Study

• Main Author: DuVal, Marc G.
• Other Authors: Cheng, Hai-Ling M.
• Language: en_ca
• Published: 2011
• Subjects: Angiogenesis; Tissue engineering; Bone regeneration; Calvarial; Rabbit; MRI; Dynamic MRI; 0564; 0567; 0574
• Online Access: http://hdl.handle.net/1807/30578

Tissue engineering is limited by inability to create early and adequate blood supply. In-vivo DCE-MRI has imaged angiogenesis in soft tissues, yet has not been considered in hard tissues. Bilateral critical defects created in parietal bones of eighteen adult rabbits were left void, treated with haluronic acid acellular matrix (HA-ACM), or HA-ACM impregnated with vascular endothelial growth factor (VegF). DCE- MRI was acquired at weeks 1,2,3,6, and 12. Histologic analysis of HA-ACM treated defects demonstrated quantitatively greater immature bone formation, increased quantity and larger blood vessels compared to void. Statistically significant greater angiogenesis evidenced by quantitative perfusion on MRI supported histologic findings. DCE MRI is a novel means of imaging angiogenesis in grafted bone defects. DCE-MRI discerns physiologically important phases of angiogenesis: Initial vasoactive response, vessel network initiation, establishment, and pruning. DCE-MRI is adaptable to non-invasive study of candidate tissue engineered constructs and in evaluating scaffolds and treatments on angiogenesis.