Markel David C, Dietz Paula, Provenzano Gina, Bou-Akl Therese, Ren Wei-Ping
Ascension Providence Hospital, Southfield, MI, USA.
Wayne State University, Detroit, MI, USA.
Arthroplast Today. 2022 Jan 15;14:231-236.e1. doi: 10.1016/j.artd.2021.12.003. eCollection 2022 Apr.
Direct attachment of tendons to metallic implants is important in orthopedics. Tissue integration depends on scaffold microstructure and composition. This study evaluated the effect of pore size of titanium on the viability and function of fibroblasts and tenocytes in a dynamic bioreactor.
Standardized Ti porous cylinders with 3 pore sizes (400, 700, and 1000 μm) were seeded with fibroblasts or tenocytes (4500 cells/μL) in silicon tubes. Cells were analyzed via alamarBlue (AB) assay in addition to scanning electron microscopy at day 7 (fibroblasts) or day 8 (tenocytes) and day 15. AB functions as a cell health indicator where functional living cells reduce the resazurin dye (blue) in the solution to resorufin (pink), and cell viability can be quantified via spectroscopy.
At day 7, fibroblasts cultured on all sizes reduced AB, with significant differences noted between 400 vs 1000 μm ( = .013) and 700 vs 1000 μm ( = .001). At day 15, fibroblasts reduced AB on all sizes with a significant difference noted between 700 vs 1000 μm ( = .004). Fibroblasts on all 3 pore sizes increased AB reduction from day 7 to day 15. Tenocytes reduced AB with significant differences between the 400 vs 700 μm ( = .049) and the 400 vs 1000 μm pore sizes at day 8. In contrast, tenocyte reduction of AB decreased from day 8 to day 15. Scanning electron microscopy performed on fibroblast cylinders showed fibroblasts reached the surface of the cylinders, confirming interconnectivity.
While both fibroblasts and tenocytes penetrated the pores, fibroblasts preferred larger size, whereas tenocytes favored smaller size. Results are encouraging since soft-tissue attachment to a metallic scaffold is difficult but clinically desirable. Future studies could be performed in an in vivo animal model.
在骨科领域，肌腱与金属植入物的直接附着至关重要。组织整合取决于支架的微观结构和组成。本研究评估了钛的孔径对动态生物反应器中成纤维细胞和肌腱细胞活力及功能的影响。
将标准化的具有3种孔径（400、700和1000μm）的钛多孔圆柱体置于硅管中，接种成纤维细胞或肌腱细胞（4500个细胞/μL）。在第7天（成纤维细胞）或第8天（肌腱细胞）以及第15天，除了进行扫描电子显微镜检查外，还通过alamarBlue（AB）检测法对细胞进行分析。AB作为细胞健康指标，功能活跃的活细胞将溶液中的刃天青染料（蓝色）还原为试卤灵（粉红色），细胞活力可通过光谱法定量。
在第7天，所有孔径上培养的成纤维细胞均能使AB还原，400μm与1000μm之间（P = 0.013）以及700μm与1000μm之间（P = 0.001）存在显著差异。在第15天，所有孔径上的成纤维细胞均能使AB还原，700μm与1000μm之间存在显著差异（P = 0.004）。所有3种孔径上的成纤维细胞从第7天到第15天AB还原量均增加。在第8天，肌腱细胞使AB还原，400μm与700μm之间（P = 0.049）以及400μm与1000μm孔径之间存在显著差异。相比之下，肌腱细胞的AB还原量从第8天到第15天有所下降。对成纤维细胞圆柱体进行的扫描电子显微镜检查显示成纤维细胞到达了圆柱体表面，证实了其连通性。
虽然成纤维细胞和肌腱细胞均能穿透孔隙，但成纤维细胞更喜欢较大孔径，而肌腱细胞更喜欢较小孔径。由于软组织与金属支架的附着困难但临床上很有必要，因此这些结果令人鼓舞。未来的研究可在体内动物模型中进行。
