Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Jun 26, 2015; 7(5): 873-882
Published online Jun 26, 2015. doi: 10.4252/wjsc.v7.i5.873
Utility of tricalcium phosphate and osteogenic matrix cell sheet constructs for bone defect reconstruction
Tomoyuki Ueha, Manabu Akahane, Takamasa Shimizu, Yoshinobu Uchihara, Yusuke Morita, Naoya Nitta, Akira Kido, Yusuke Inagaki, Kenji Kawate, Yasuhito Tanaka
Tomoyuki Ueha, Takamasa Shimizu, Yoshinobu Uchihara, Akira Kido, Yusuke Inagaki, Yasuhito Tanaka, Department of Orthopedic Surgery, Nara Medical University, Kashihara, Nara 634-8522, Japan
Manabu Akahane, Department of Public Health, Health Management and Policy, Nara Medical University Faculty of Medicine, Kashihara, Nara 634-8521, Japan
Yusuke Morita, Naoya Nitta, Department of Biomedical Engineering, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan
Kenji Kawate, Department of Arthroplasty and Regenerative Medicine, Nara Medical University, Kashihara, Nara 634-8522, Japan
Author contributions: Ueha T and Akahane M designed the study and prepared the manuscript; Shimizu T and Uchihara Y assisted in the study processes and preparations; Morita Y and Nitta N participated in the biomechanical tests; Kido A, Inagaki Y, Kawate K and Tanaka Y assisted in the manuscript preparation and critically reviewed the manuscript; all authors read and approved the final manuscript.
Supported by Grant-in-Aid for Young Scientists (KAKENHI).
Ethics approval: The animal protocol was designed to minimize pain or discomfort to the animals. The animals were acclimatized to laboratory conditions (23 °C, 12h/12h light/dark, ad libitum access to food and water).
Institutional animal care and use committee: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Nara Medical University.
Conflict-of-interest: The authors state that they have no conflicts of interest to disclose.
Data sharing: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Manabu Akahane, MD, PhD, Department of Public Health, Health Management and Policy, Nara Medical University Faculty of Medicine, 840 Shijo-cho, Kashihara, Nara 634-8521, Japan.
Telephone: +81-744-223051 Fax: +81-744-220037
Received: September 30, 2014
Peer-review started: October 1, 2014
First decision: October 28, 2014
Revised: January 27, 2015
Accepted: March 18, 2015
Article in press: March 20, 2015
Published online: June 26, 2015

AIM: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects.

METHODS: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both. Constructs were implanted into a femoral defect model in rats and bone growth was evaluated by radiography, histology, biochemistry, and mechanical testing after 8 wk.

RESULTS: In bone defects, constructs implanted with cell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast to TCP seeded with BMSCs, which resulted in bone non-union. Wrapping TCP constructs with osteogenic matrix cell sheets increased their osteogenic potential and resulting bone formation, compared with conventional bone tissue engineering TCP scaffolds seeded with BMSCs. The compressive stiffness (mean ± SD) values were 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6 MPa for BMSC/TCP/Sheet constructs with continuous bone formation, BMSC/TCP/Sheet constructs with segmental bone formation, and BMSC/TCP constructs, respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation was significantly higher than those with segmental bone formation and BMSC/TCP constructs.

CONCLUSION: This technique is an improvement over current methods, such as TCP substitution, and is useful for hard tissue reconstruction and inducing earlier bone union in defects.

Keywords: Bone marrow stromal cells, Osteogenesis, Bone regeneration, Tissue engineering, Calcium phosphate

Core tip: The treatment of bone defects is a common clinical problem for orthopedic surgeons. Artificial bone combined with cultured bone marrow stromal cells (BMSCs) has been examined and applied for the treatment of clinical cases such as small bone defects. In the present study, we developed constructs of BMSCs and beta-tricalcium phosphate (TCP) combined with osteogenic matrix cell sheets (BMSC/TCP/Sheet constructs), which showed a vigorous osteogenic potential compared with conventionally engineered bone tissue structures consisting of BMSC/TCP constructs. The BMSC/TCP/Sheet constructs will be useful for reconstruction of hard tissues, such as bone defects, as new tissue-engineered bone.