JBJS - 2026-03-12 - Journal Article
Prevascularized Bone Marrow-Derived Mesenchymal Stem Cell Sheets Promote Tendon-Bone Integration in Rotator Cuff Repair.
Li Y, Chen Y, Zhu Y, Li D, Liao L, Li W, Liu Q
Topics
Key Takeaway
Prevascularized BMSC sheets increased ultimate failure load by 40% (156.89 vs 111.67 N) and vessel density by 52% at the tendon-bone interface compared to standard BMSC sheets in a rabbit rotator cuff model at 6 weeks.
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Summary
This study asked whether prevascularization of BMSC sheets via endothelial cell coculture improves tendon-bone interface healing compared to standard BMSC sheets in a rabbit infraspinatus repair model. Prevascularized sheets produced significantly greater α-SMA-positive vessel density (16.16 vs 10.63/mm²), collagen type II area (86.96 vs 40.25 μm²), IL-10 expression, ultimate failure load (156.89 vs 111.67 N), and stiffness (37.27 vs 27.16 N/mm). All differences reached statistical significance at 6 weeks.
Key Limitation
Rabbit infraspinatus anatomy and healing biology differ substantially from the human supraspinatus, and the 6-week endpoint does not capture remodeling or long-term mechanical durability.
Original Abstract
BACKGROUND
Limited vascularization at the tendon-bone interface (TBI) hinders rotator cuff (RC) healing. Although cell sheet technology has shown promise for interfacial repair, prevascularization strategies remain underexplored.
METHODS
Twenty female New Zealand rabbits underwent bilateral infraspinatus tendon repair and were randomized to receive either bone marrow-derived mesenchymal stem cell (BMSC) sheets or prevascularized BMSC sheets generated by coculture with endothelial cells, implanted at the TBI. An age- and weight-matched uninjured group served as a control. Healing at 6 weeks was assessed by gross observation, histology, immunohistochemistry, gene expression, and biomechanical testing.
RESULTS
Prevascularization of the BMSC sheets enhanced TBI vascularization, indicated by greater density of α-smooth muscle actin-positive vessels (16.16 ± 2.81 versus 10.63 ± 2.79/mm2, p = 0.0079). Immunohistochemistry demonstrated greater areas positive for collagen type II alpha 1 (86.96 ± 29.95 versus 40.25 ± 11.96 μm2, p = 0.0079) and interleukin 10 (14.93 ± 4.79 versus 7.43 ± 2.48 μm2, p = 0.0159). Biomechanically, prevascularization of the sheets yielded greater ultimate failure load (156.89 ± 51.92 versus 111.67 ± 27.51 N, p = 0.0364) and stiffness (37.27 ± 12.16 versus 27.16 ± 7.33 N/mm, p = 0.0486).
CONCLUSIONS
Prevascularization of BMSC sheets was able to promote angiogenesis and improve structural and mechanical aspects of tendon-bone healing.
CLINICAL RELEVANCE
Prevascularized BMSC sheets may represent a biologic adjunct to enhance tendon-bone healing in RC repair.