Microcomputed tomography (microCT) analysis of tissue engineering scaffolds and bone regeneration in vivo . (A) MicroCT reconstruction of mesenchymal stem cell-mediated bone regeneration in a bilateral cranial defect model treated with a high-density human mesenchymal stem cell (hMSC) construct incorporating growth factor-loaded microparticles (left) or empty control (right), and sagittal-cut views of three-dimensional thickness mapping overlay of defect regions (Phuong Dang and Eben Aslberg, in preparation). (B) Poly(L/DL)-lactide tri-calcium phosphate (PLDL-TCP) scaffold created according to the protocol of  featuring oriented microporosity and central core showing isometric view and transverse cross-section. (C) In vivo bone formation in a rat femoral bone defect model implanted with cored scaffolds from (A) loaded with rhBMP-2 in alginate hydrogel (McDermott and collegues, in preparation) or (D) hydrogel-mediated delivery of rhBMP-2 within a polycaprolactone nanofiber mesh without a structural scaffold in the defect. Reproduced with permission from . (E) In vivo microCT-based longitudinal quantification of bone formation over time (dotted to solid lines) for various doses of BMP-2 in the hybrid nanofiber mesh/alginate delivery system. Reproduced with permission from .