title: Osteogenic matrix sheet-cell transplantation using osteoblastic cell sheet resulted in bone formation without scaffold at an ectopic site.
abstract: We previously reported that in vivo bone formation could be observed in composites of porous hydroxyapatite (HA) scaffolds and cultured mesenchymal stem cells (MSCs). In the present study, we developed a new method for transplantation of cultured MSCs without the necessity of using a scaffold to form bone tissue. MSCs were culture-expanded and lifted as cell sheet structures. These cell sheets, designated osteogenic matrix sheets, showed positive alkaline phosphatase (ALP) staining, high ALP activities and high osteocalcin (OC) contents, indicating their osteogenic potential. We transplanted these sheets into subcutaneous sites in rats to assess whether they possessed in vivo bone-forming capability. The transplanted sheets showed mineralized matrix together with osteocytes and an active osteoblast lining, indicating new bone formation, at 6 weeks after transplantation. HA scaffolds were also wrapped with the sheets to make HA/sheet composites and implanted into subcutaneous sites in rats. Histological sections of the composites revealed bone formation in the HA pores at 4 weeks after implantation. Our present results indicate that MSCs can be cultured as sheet structures, and the resulting sheets themselves or HA-sheet composites represent osteogenic implants that can be used for hard tissue reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University School of Medicine, Nara, Japan. makahane@naramed-u.ac.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Akahane
authors.forename: Akifumi
authors.initials: A
authors.lastname: Nakamura
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohgushi
authors.forename: Hideki
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Dohi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takakura
mesh_terms: D000469:Alkaline Phosphatase; D000818:Animals; D017690:Cell Transplantation; D002516:Ceramics; D004210:Dissection; D017886:Durapatite; D005109:Extracellular Matrix / Q000378:metabolism*; D008297:Male; D010006:Osteoblasts / Q000166:cytology*; D015675:Osteocalcin; D010012:Osteogenesis; D019736:Prostheses and Implants; D051381:Rats; D011916:Rats, Inbred F344; D054457:Tissue Scaffolds
chemical_list: D015675:Osteocalcin; D017886:Durapatite; D000469:Alkaline Phosphatase