Affiliations: Tissue Engineering Research Center (TERC), Tsukuba Center 4, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305‐8562, Japan | Department of Orthopaedic Surgery, Fudan University, Zhongshan Hospital, Shanghai 200032, P.R. China | CREST JST (Core Research for Evolutional Science and Technology, Japan Science and Technology) | Department of Orthopaedic Surgery, Tokyo Medical and Dental University, Yushima Bunkyo‐Ku, Japan | Advanced Material Laboratory, National Institute for Material Science (NIMS), Namiki 1‐1, Tsukuba Ibaraki, Japan | Biomedical Engineering Laboratory, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
Abstract: In this study, we hypothesize that loading more marrow‐derived mesenchymal stem cells (MSCs) into porous material by using a low‐pressure system during subculture, creating a composite which combines MSCs and a novel mechanical reinforced porous hydroxyapatite, can result in more bone tissue formation in vivo. Within 26 weeks postimplantation, we examined in vivo bone formation of the experimental group with 100 mmHg pressure applied to porous HA blocks loaded with MSCs. For in vivo testing, the 2‐week subcultured HA/MSC composites were implanted into subcutaneous sites of syngeneic rats. These implants were harvested at 13 and 26 weeks after implantation. SEM showed that the pore surface is covered by osteoblasts as well as collagenous extracellular matrix at 13 weeks. Light microscopy revealed the quantity of bone at 26 weeks was greater than at 13 weeks. These results showed that the novel mechanical reinforced porous HA combined with MSC has more potential for bone formation at 100 mmHg, making this method very efficient for bone reconstruction.
