Evaluation of solid free-form fabrication-based scaffolds seeded with osteoblasts and human umbilical vein endothelial cells for use in vivo osteogenesis

We investigated the feasibility of using solid free-form fabrication (SFF)-based scaffolds seeded with osteoblasts, derived from human adipose-derived stem cells, and human umbilical vein endothelial cells (HUVECs) to enhance osteogenesis. To accomplish this goal, SFF-based polycaprolactone/ poly-lactic-co-glycolic acid/tricalcium phosphate scaffolds were fabricated using a multihead deposition system, which is one SFF technique. The blended polycaprolactone/poly-lactic-co-glycolic acid/TCP scaffolds were seeded with human osteoblasts and HUVECs and implanted into calvaria defects in rats. At 8 and 12 weeks after implantation, microcomputed tomography, real-time polymerase chain reaction, and histological assays (hematoxylin and eosin staining and Alizarin red staining) were conducted to determine the effects of SFF-based scaffolds on osteogenic potential. In vivo experiments indicated that the osteoblast-only and osteoblast-HUVEC group produced bone formation. Additionally, scaffolds in the osteoblast-HUVEC group had the largest area of new bone tissue. Therefore, we demonstrated through microcomputed tomography and histological assays that scaffolds seeded with both human osteoblasts and HUVECs were superior to other groups for effective bone formation.