■肌腱组织工程需要无支架技术,以实现安全和长期的临床应用,并探索肌腱细胞的替代细胞来源。因此,我们使用Bio-3D打印机系统在体外拉伸培养下,从正常人真皮成纤维细胞(NHDF)开发的无支架生物三维(3D)构建体中评估了肌腱的形成。
■使用生物3D打印机从包含NHDF的120个多细胞球体构建无支架环状组织。在有或没有内部拉伸装置的情况下,在静态拉伸载荷下体外培养环状组织(拉伸载荷和无张力组),随着拉伸强度的增加,每周应用于拉伸负荷组。在设备上进行4或8周培养后,我们根据肌腱成熟评分和组织中部的免疫组织学检查结果评估了两组的组织学结果(分别为n=4).
■张力加载组的组织学显示,胶原蛋白沉积增加的纵向排列的胶原纤维和长时间培养的纺锤形细胞。相比之下,无张力组无组织细胞排列或胶原纤维结构。此外,在第8周时,与无张力组相比,张力负荷组的肌腱成熟评分显著改善.此外,免疫组织化学显示,在第8周时,张力负荷组的生腱蛋白C分布在张力负荷方向上呈平行排列,在第4周和第8周,其显示出比无张力组更强的巩膜染色强度。
■NHDF生成的无支架Bio-3D构建体经历了重塑,并在体外拉伸培养下形成了肌腱样结构。
UNASSIGNED: Tendon tissue engineering requires scaffold-free techniques for safe and long-term clinical applications and to explore alternative cell sources to tenocytes. Therefore, we histologically assessed tendon formation in a scaffold-free Bio-three-dimensional (3D) construct developed from normal human dermal fibroblasts (NHDFs) using our Bio-3D printer system under tensile culture in vitro.
UNASSIGNED: Scaffold-free ring-like tissues were constructed from 120 multicellular spheroids comprising NHDFs using a bio-3D printer. Ring-like tissues were cultured in vitro under static tensile-loading with or without in-house tensile devices (tension-loaded and tension-free groups), with increases in tensile strength applied weekly to the tensile-loaded group. After a 4 or 8-week culture on the device, we evaluated histological findings according to tendon-maturing score and immunohistological findings of the middle portion of the tissues for both groups (n = 4, respectively).
UNASSIGNED: Histology of the tension-loaded group revealed longitudinally aligned collagen fibers with increased collagen deposition and spindle-shaped cells with prolonged culture. By contrast, the tension-free group showed no organized cell arrangement or collagen fiber structure. Additionally, the tension-loaded group showed a significantly improved tendon-maturing score as compared with that for the tension-free group at week 8. Moreover, immunohistochemistry revealed tenascin C distribution with a parallel arrangement in the tensile-loading direction at week 8 in the tension-loaded group, which exhibited stronger scleraxis-staining intensity than that observed in the tension-free group at weeks 4 and 8.
UNASSIGNED: The NHDF-generated scaffold-free Bio-3D construct underwent remodeling and formed tendon-like structures under tensile culture in vitro.