Abstract:
In recent years, bridging repair has emerged as an effective approach for the treatment of massive rotator cuff tears (MRCTs). The objective of this study was to develop a composite patch that combines superior mechanical strength and biocompatibility and evaluate its potential for enhancing the outcomes of bridging repair for MRCTs. The composite patch, referred to as the PET-matrix patch (PM), was fabricated by immersing a plain-woven PET patch in decellularized matrix gel and utilizing the freeze-drying technique. The results demonstrated that the PM has reliable mechanical properties, with a maximum failure load of up to 480 N. The decellularized matrix sponge (DMS), present on the surface of the PM, displayed a loose and porous structure, with an average pore size of 62.51 μm and a porosity of 95.43%. In vitro experiments showed significant elongation of tenocytes on the DMS, with cells spanning across multiple pores and extending multiple protrusions as observed on SEM images. In contrast, tenocytes on the PET patch appeared smaller in size and lacked significant elongation. Additionally, the DMS facilitated the proliferation, migration and differentiation of tenocytes. In a rabbit model of chronic MRCTs, the PM group showed superior outcomes compared to the PET group at 4, 8 and 12 weeks after bridging repair. The PM group displayed significantly higher tendon maturing score, larger collagen diameter in the regenerated tendon and improved tendon-to-bone healing scores compared to the PET group (P < 0.05). Moreover, the maximum failure load of the tendon-bone complex in the PM group was significantly higher than that in the PET group (P < 0.05). In summary, the PM possesses reliable mechanical properties and excellent cytocompatibility, which can significantly improve the outcomes of bridging repair for chronic MRCTs in rabbits. Therefore, it holds great potential for clinical applications.
摘要:
近年来,桥接修复已成为治疗大量肩袖撕裂(MRCT)的有效方法.本研究的目的是开发一种结合了优异的机械强度和生物相容性的复合贴片,并评估其增强MRCT桥接修复结果的潜力。复合贴片,称为PET矩阵贴片(PM),通过将平织PET贴片浸入脱细胞基质凝胶中并利用冷冻干燥技术来制造。结果表明,PM具有可靠的力学性能,最大破坏载荷高达480N。脱细胞基质海绵(DMS),出现在PM的表面上,显示出松散和多孔的结构,平均孔径为62.51μm,孔隙率为95.43%。体外实验显示DMS上肌腱细胞显著伸长,如在SEM图像上观察到的,细胞跨越多个孔并延伸多个突起。相比之下,PET贴片上的肌腱细胞尺寸较小,并且缺乏明显的伸长。此外,DMS促进了扩散,肌腱细胞的迁移和分化。在兔慢性MRCT模型中,与PET组相比,PM组在桥接修复后第4,8和12周的结局更优.PM组肌腱成熟评分明显较高,与PET组相比,再生肌腱的胶原直径更大,肌腱-骨愈合评分提高(P<0.05)。此外,PM组腱-骨复合体的最大破坏负荷明显高于PET组(P<0.05)。总之,PM具有可靠的机械性能和优异的细胞相容性,可以明显改善兔慢性MRCT桥接修复的效果。因此,它具有巨大的临床应用潜力。