Parks College of Engineering, Aviation and Technology, Saint Louis University, St Louis, MO 63103, United States of America.
Biomed Mater. 2018 Aug 30;13(6):065007. doi: 10.1088/1748-605X/aad915.
Skeletal muscle has a remarkable regenerative capability following mild physical or chemical insult. However, following a critical loss of muscle tissue, the regeneration process is impaired due to the inadequate myogenic activity of muscle resident stem cells (i.e., satellite cells). Laminin (LM) is a heterotrimeric structural protein in the satellite cell niche that is crucial for maintaining its function. In this study, we created hydrogels composed of poly (ethylene glycol) (PEG) and LM-111 to provide an elastic substrate for satellite cell proliferation at the site of injury. The PEG-LM111 conjugates were mixed with 5% and 10% (w/v) pure PEG-diacrylate (PEGDA) and photopolymerized to form 5% and 10% PEGLM gels. Pure 5% and 10% PEGDA gels were used as controls. The modulus of both hydrogels containing 10% (w/v) PEGDA was significantly higher than the hydrogels containing 5% (w/v) PEGDA. The 5% PEGLM hydrogels showed significantly higher swelling in aqueous medium suggesting a more porous structure. CC myoblasts cultured on the softer 5% PEGLM hydrogels showed a flat and spread-out morphology when compared to the rounded, multicell clusters formed on the 5% PEGDA, 10% PEGDA, and 10% PEGLM hydrogels. The 5% PEGLM hydrogels also promoted a significant increase in both vascular endothelial growth factor and interleukin-6 (IL-6) production from the myoblasts. Additionally, the expression of MyoD was significantly higher while that of myogenin and α-actinin trended higher on the 5% PEGLM hydrogels compared to 5% PEGDA on day 5. Our data suggests that the introduction of LM-111 into compliant PEG hydrogels promoted myoblast adhesion, survival, pro-regenerative growth factor production, and myogenic activity.
骨骼肌在受到轻微的物理或化学损伤后具有显著的再生能力。然而，在肌肉组织发生严重损失后，由于肌肉常驻干细胞（即卫星细胞）的成肌活性不足，再生过程受损。层粘连蛋白（LM）是卫星细胞龛中的一种异三聚体结构蛋白，对维持其功能至关重要。在这项研究中，我们创建了由聚乙二醇（PEG）和 LM-111 组成的水凝胶，为损伤部位的卫星细胞增殖提供了弹性基质。将 PEG-LM111 缀合物与 5%和 10%（w/v）纯 PEG-二丙烯酸酯（PEGDA）混合，并进行光聚合以形成 5%和 10%PEGLM 凝胶。纯 5%和 10%PEGDA 凝胶用作对照。含有 10%（w/v）PEGDA 的两种水凝胶的模量均明显高于含有 5%（w/v）PEGDA 的水凝胶。含有 5%（w/v）PEGDA 的水凝胶在水性介质中的溶胀率明显较高，表明其具有更多孔的结构。与在 5%PEGDA、10%PEGDA 和 10%PEGLM 水凝胶上形成的圆形、多细胞簇相比，在较软的 5%PEGLM 水凝胶上培养的 CC 成肌细胞表现出更平坦和展开的形态。5%PEGLM 水凝胶还显著促进了成肌细胞中血管内皮生长因子和白细胞介素-6（IL-6）的产生。此外，与 5%PEGDA 相比，在第 5 天，5%PEGLM 水凝胶上 MyoD 的表达明显更高，而 myogenin 和 α-actinin 的表达也呈上升趋势。我们的数据表明，将 LM-111 引入顺应性 PEG 水凝胶中可促进成肌细胞黏附、存活、产生促再生生长因子和肌生成活性。
