title: The effect of implantation on scaffoldless three-dimensional engineered bone constructs.
abstract: Our laboratory has previously developed scaffoldless engineered bone constructs (EBC). Bone marrow stromal cells (BMSC) were harvested from rat femur and cultured in medium that induced osteogenic differentiation. After reaching confluence, the monolayer of cells contracted around two constraint points forming a cylinder. EBCs were placed in small diameter (0.5905 x 0.0625 in.) or large diameter (0.5905 x 0.125 in.) silicone tubing and implanted intramuscularly in the hind limb of a rat. Bone mineral content (BMC) of the EBC was analyzed before implantation and at 1 and 2 mo following implantation and compared to that of native femur bone at different stages of development. Negligible BMC was observed in E-20 femur or EBCs prior to implantation. One-month implantation in both small and large tubing increased BMC in the EBC. BMC of EBC from large tubing was greater than in 14 d rat neonatal femurs, but was 2% and 3% of BMC content in adult bone after 1 and 2 mo of implantation, respectively. Alizarine Red and osteopontin staining of the EBCs before and after implantation confirmed increased bone mineralization in the implanted EBCs. Implanted EBCs also had extensive vascularization. Our data suggest that BMSC can be successfully used for the generation of scaffoldless EBC, and this model can be potentially used for the generation of autologous bone transplants in humans.
authors.affiliation: Biomedical Engineering, University of Michigan, 2025 BSRB, Ann Arbor, MI 48109-2200, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Smietana
authors.forename: Fatima N
authors.initials: FN
authors.lastname: Syed-Picard
authors.forename: Jinjin
authors.initials: J
authors.lastname: Ma
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kostrominova
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Arruda
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Larkin
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D000831:Animals, Newborn; D015519:Bone Density / Q000502:physiology; D001854:Bone Marrow Cells / Q000166:cytology; D001842:Bone and Bones / Q000166:cytology / Q000000981:diagnostic imaging / Q000502:physiology*; D020007:Implants, Experimental; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D019919:Prosthesis Implantation; D051381:Rats; D011916:Rats, Inbred F344; D017154:Stromal Cells / Q000166:cytology; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1