Awad Hani A, Boivin Gregory P, Dressler Matthew R, Smith Frost N L, Young Randell G, Butler David L
Noyes-Giannestras Biomechanics Laboratories, Department of Biomedical Engineering, University of Cincinnati, 2901 Campus Drive, P.O. Box 210048, OH 45221-0048, USA.
J Orthop Res. 2003 May;21(3):420-31. doi: 10.1016/S0736-0266(02)00163-8.
Collagen gels were seeded with rabbit bone marrow-derived mesenchymal stem cells (MSCs) and contracted onto sutures at initial cell densities of 1, 4, and 8 million cells/ml. These MSC-collagen composites were then implanted into full thickness, full length, central defects created in the patellar tendons of the animals providing the cells. These autologous repairs were compared to natural repair of identical defects on the contralateral side. Biomechanical, histological, and morphometric analyses were performed on both repair tissue types at 6, 12, and 26 weeks after surgery. Repair tissues containing the MSC-collagen composites showed significantly higher maximum stresses and moduli than natural repair tissues at 12 and 26 weeks postsurgery. However, no significant differences were observed in any dimensional or mechanical properties of the repair tissues across seeding densities at each evaluation time. By 26 weeks, the repairs grafted with MSC-collagen composites were one-fourth of the maximum stress of the normal central portion of the patellar tendon with bone ends. The modulus and maximum stress of the repair tissues grafted with MSC-collagen composites increased at significantly faster rates than did natural repairs over time. Unexpectedly, 28% of the MSC-collagen grafted tendons formed bone in the regenerating repair site. Except for increased repair tissue volume, no significant differences in cellular organization or histological appearance were observed between the natural repairs and MSC-collagen grafted repairs. Overall, these results show that surgically implanting tissue engineered MSC-collagen composites significantly improves the biomechanical properties of tendon repair tissues, although greater MSC concentrations produced no additional significant histological or biomechanical improvement.
将兔骨髓间充质干细胞（MSCs）接种到胶原凝胶中，并以100万、400万和800万个细胞/毫升的初始细胞密度收缩到缝合线上。然后将这些MSC-胶原复合材料植入提供细胞的动物髌腱中创建的全层、全长、中央缺损处。将这些自体修复与对侧相同缺损的自然修复进行比较。在手术后6周、12周和26周对两种修复组织类型进行生物力学、组织学和形态计量学分析。在手术后12周和26周，含有MSC-胶原复合材料的修复组织显示出比自然修复组织显著更高的最大应力和模量。然而，在每个评估时间点，不同接种密度的修复组织在任何尺寸或力学性能方面均未观察到显著差异。到26周时，移植MSC-胶原复合材料的修复组织的最大应力是带骨端的髌腱正常中央部分的四分之一。随着时间的推移，移植MSC-胶原复合材料的修复组织的模量和最大应力的增加速度明显快于自然修复组织。出乎意料的是，28%的移植MSC-胶原的肌腱在再生修复部位形成了骨。除了修复组织体积增加外，自然修复和移植MSC-胶原的修复在细胞组织或组织学外观上没有观察到显著差异。总体而言，这些结果表明，手术植入组织工程化的MSC-胶原复合材料可显著改善肌腱修复组织的生物力学性能，尽管更高的MSC浓度并未产生额外的显著组织学或生物力学改善。
