A comparative study of tissue-engineered constructs from and coral in a large animal bone defect model.

Objectives: To compare the therapeutic potential of tissue-engineered constructs (TECs) combining mesenchymal stem cells (MSCs) and coral granules from either or to repair large bone defects.

Materials And Methods: Bone marrow-derived, autologous MSCs were seeded on or coral granules in a perfusion bioreactor. -TECs (n = 7), -TECs (n = 6) and bone autografts (n = 2) were then implanted into 25 mm long metatarsal diaphyseal defects in sheep. Bimonthly radiographic follow-up was completed until killing four months post-operatively. Explants were subsequently processed for microCT and histology to assess bone formation and coral bioresorption. Statistical analyses comprised Mann-Whitney, -test and Kruskal-Wallis tests. Data were expressed as mean and standard deviation.

Results: A two-fold increaseof newly formed bone volume was observed for -TECs when compared with -TECs (14 sd 1089 mm 782 sd 507 mm; p = 0.09). Bone union was consistent with autograft (1960 sd 518 mm). The kinetics of bioresorption and bioresorption rates at four months were different for -TECs and -TECs (81% sd 5% 94% sd 6%; p = 0.04). In comparing the defects that healed with those that did not, we observed that, when major bioresorption of coral at two months occurs and a scaffold material bioresorption rate superior to 90% at four months is achieved, bone nonunion consistently occurred using coral-based TECs.

Discussion: Bone regeneration in critical-size defects could be obtained with full bioresorption of the scaffold using coral-based TECs in a large animal model. The superior performance of -TECs brings us closer to a clinical application, probably because of more suitable bioresorption kinetics. However, nonunion still occurred in nearly half of the bone defects. A. Decambron, M. Manassero, M. Bensidhoum, B. Lecuelle, D. Logeart-Avramoglou, H. Petite, V. Viateau. A comparative study of tissue-engineered constructs from and coral in a large animal bone defect model. 2017;6:208-215. DOI: 10.1302/2046-3758.64.BJR-2016-0236.R1.