Byung Hoon Lee1, Jong Nam Park2, Eun Ju Lee2, Young Wan Moon3, Joon Ho Wang3,4,5. 1. Department of Orthopedic Surgery, Kang-Dong Sacred Heart Hospital, Hallym University Medical School, Seoul, Republic of Korea. 2. Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea. 3. Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. 4. Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea. 5. Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.
Abstract
BACKGROUND: Engraftment and longevity of transplanted cells are crucial for stem cell-based cartilage treatment. PURPOSE: To determine whether cultured spherical cell masses of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) could improve engraftment at defect sites and to examine their corresponding effects on osteochondral regeneration. STUDY DESIGN: Controlled laboratory study. METHODS: A cylindrical osteochondral defect (5 mm wide × 5 mm deep) was created in trochlear grooves of rabbit knees. The single-cell type of hBM-MSCs with fibrin glue, the spherical type of hBM-MSCs with fibrin glue, and cell-free fibrin glue (control) were each implanted into osteochondral defect sites. A total of 18 rabbit knees were randomly assigned to 1 of the 3 groups (3 rabbits per group). Animals were sacrificed at 6 and 12 weeks after transplantation. Repaired tissues were evaluated via gross examination, histologic examination, and immunofluorescence analysis. RESULTS: Transplantation with spherical hBM-MSCs exhibited superior overall osteochondral restoration when compared with the single-type group, as evidenced by well-ordered mature collagen fibrils produced during subchondral bone formation in the zonation phenomenon. Immunofluorescence analysis of osteochondral defect areas with human-specific antigen revealed a larger number of mesenchymal stem cells in the spherical-type group than the single cell-type group. CONCLUSION: Transplantation of spherical hBM-MSCs was better than single cells from monolayer culture in improving osteochondral regeneration. CLINICAL RELEVANCE: The findings demonstrate a simple strategy for enhancing the potency of stem cells required for restoration of osteochondral defects. Furthermore, this strategy may be implemented with other types of stem/progenitor cell-based therapies.
BACKGROUND: Engraftment and longevity of transplanted cells are crucial for stem cell-based cartilage treatment. PURPOSE: To determine whether cultured spherical cell masses of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) could improve engraftment at defect sites and to examine their corresponding effects on osteochondral regeneration. STUDY DESIGN: Controlled laboratory study. METHODS: A cylindrical osteochondral defect (5 mm wide × 5 mm deep) was created in trochlear grooves of rabbit knees. The single-cell type of hBM-MSCs with fibrin glue, the spherical type of hBM-MSCs with fibrin glue, and cell-free fibrin glue (control) were each implanted into osteochondral defect sites. A total of 18 rabbit knees were randomly assigned to 1 of the 3 groups (3 rabbits per group). Animals were sacrificed at 6 and 12 weeks after transplantation. Repaired tissues were evaluated via gross examination, histologic examination, and immunofluorescence analysis. RESULTS: Transplantation with spherical hBM-MSCs exhibited superior overall osteochondral restoration when compared with the single-type group, as evidenced by well-ordered mature collagen fibrils produced during subchondral bone formation in the zonation phenomenon. Immunofluorescence analysis of osteochondral defect areas with human-specific antigen revealed a larger number of mesenchymal stem cells in the spherical-type group than the single cell-type group. CONCLUSION: Transplantation of spherical hBM-MSCs was better than single cells from monolayer culture in improving osteochondral regeneration. CLINICAL RELEVANCE: The findings demonstrate a simple strategy for enhancing the potency of stem cells required for restoration of osteochondral defects. Furthermore, this strategy may be implemented with other types of stem/progenitor cell-based therapies.