Bone

Bone

Current methodologies for engineering both bone utilize scaffolds that promote adhesion, migration, and proliferation of cultured osteogenic cells. While scaffolding strategies appear to promote osteogenic or fibroblastic cell growth, limitations such as immune rejection, degradation, and non-physiological mechanical properties of the scaffold need to be considered when used for bone repair. To avoid these limitations, our laboratory has developed a scaffold-less method to engineer three-dimensional (3D) bone (EBCs) constructs from bone marrow stromal cells (BMSCs). Histochemical and functional analyses of the EBCs indicate mineralization, enzyme activities, collagen content, bone density and mechanical properties analogous to those of fetal bone. Our recent work with implantation of our EBCs suggests that our in vitro engineered tissues grow and remodel quickly in vivo to an advanced phenotype and functionality. Four and eight weeks of ectopic implantation of EBCs under strain-shielded conditions led to more developmentally advanced structure analogous to those of neonatal bone at 7 and 28 days of age, respectively.