Masayuki Shimaya

Publications (2)4.27 Total impact

• Article: [Articular cartilage regeneration with synovial mesenchymal stem cells].

  Ichiro Sekiya, Takeshi Muneta, Hideyuki Koga, Akimoto Nimura, Toshiyuki Morito, Masayuki Shimaya, Tomoyuki Mochizuki, Yuko Segawa, Yusuke Sakaguchi, Kunikazu Tsuji, Shizuko Ichinose
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  ABSTRACT: Cell transplantation has shown to be a promising strategy to repair cartilage defects. Mesenchymal stem cells derived from synovium have been shown to be a superior cell source for cartilage regeneration to those from other mesenchymal tissues due to their higher rates of colony formation, proliferation potential with autologous serum, and in vitro/vivo chondrogenic potentials. We have found that approximately 60% of synovial mesenchymal stem cells placed on cartilage defects adhered to the defect within 10 min, and the addition of magnesium enhanced this percentage further, which resulted in better cartilage regeneration. Based upon several basic research studies performed in our lab, we have begun the transplantation of synovial stem cells arthroscopically in a clinical study for the treatment of cartilage defects. To date, no adverse events have been reported in the study. Regeneration of cartilage, reduction in defect size and an improvement of symptoms have been obtained in most patients over the last 3 years.
  Clinical calcium 06/2011; 21(6):879-89.
• Source

  Available from: PubMed Central

  Article: Local adherent technique for transplanting mesenchymal stem cells as a potential treatment of cartilage defect.

  Hideyuki Koga, Masayuki Shimaya, Takeshi Muneta, Akimoto Nimura, Toshiyuki Morito, Masaya Hayashi, Shiro Suzuki, Young-Jin Ju, Tomoyuki Mochizuki, Ichiro Sekiya
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  ABSTRACT: Current cell therapy for cartilage regeneration requires invasive procedures, periosteal coverage and scaffold use. We have developed a novel transplantation method with synovial mesenchymal stem cells (MSCs) to adhere to the cartilage defect. For ex vivo analysis in rabbits, the cartilage defect was faced upward, filled with synovial MSC suspension, and held stationary for 2.5 to 15 minutes. The number of attached cells was examined. For in vivo analysis in rabbits, an autologous synovial MSC suspension was placed on the cartilage defect, and the position was maintained for 10 minutes to adhere the cells to the defect. For the control, either the same cell suspension was injected intra-articularly or the defects were left empty. The three groups were compared macroscopically and histologically. For ex vivo analysis in humans, in addition to the similar experiment in rabbits, the expression and effects of neutralizing antibodies for adhesion molecules were examined. Ex vivo analysis in rabbits demonstrated that the number of attached cells increased in a time-dependent manner, and more than 60% of cells attached within 10 minutes. The in vivo study showed that a large number of transplanted synovial MSCs attached to the defect at 1 day, and the cartilage defect improved at 24 weeks. The histological score was consistently better than the scores of the two control groups (same cell suspension injected intra-articularly or defects left empty) at 4, 12, and 24 weeks. Ex vivo analysis in humans provided similar results to those in rabbits. Intercellular adhesion molecule 1-positive cells increased between 1 minute and 10 minutes, and neutralizing antibodies for intercellular adhesion molecule 1, vascular cell adhesion molecule 1 and activated leukocyte-cell adhesion molecule inhibited the attachment. Placing MSC suspension on the cartilage defect for 10 minutes resulted in adherence of >60% of synovial MSCs to the defect, and promoted cartilage regeneration. This adherent method makes it possible to adhere MSCs with low invasion, without periosteal coverage, and without a scaffold.
  Arthritis research & therapy 08/2008; 10(4):R84. · 4.27 Impact Factor