Electrical stimulation (ES) has provided enhanced chondrogenesis of mesenchymal stem cells (MSCs) cultured in micro-mass without the addition of exogenous growth factors. In this study, we demonstrate for the first time that ES of MSCs encapsulated in an injectable hyaluronic acid (HA) - gelatin (GEL) mixture enhances the chondrogenic potential of the hydrogel. Samples were stimulated for 21 days with 10 mV/cm at 60 kHz, applied for 30 min every 6 h a day. Mechanical properties of hydrogels were higher if the precursors were dissolved in Calcium-Free Krebs Ringer Buffer (G' = 1141 ± 23 Pa) compared to those diluted in culture media (G' = 213 ± 19 Pa). Cells within stimulated hydrogels were rounder (55%) than non-stimulated cultures (32%) (p = 0.005). Chondrogenic markers such as SOX-9 and aggrecan were higher in stimulated hydrogels compared to controls. The ES demonstrated that normalized content of glycosaminoglycans and collagen to DNA was slightly higher in stimulated samples. Additionally, collagen type II normalized to total collagen was 2.43 times higher in stimulated hydrogels. These findings make ES a promising tool for enhancing articular cartilage tissue engineering outcomes by combining hydrogels and MSCs.

中文翻译：

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电刺激对透明质酸-明胶注射水凝胶中培养的间充质干细胞软骨分化的影响。

电刺激（ES）增强了以微质量培养的间充质干细胞（MSC）的软骨形成，而没有添加外源性生长因子。在这项研究中，我们首次证明了封装在可注射的透明质酸（HA）-明胶（GEL）混合物中的MSC的ES增强了水凝胶的软骨形成潜能。将样品在60 kHz下以10 mV / cm刺激21天，每6天每天施加30分钟。如果将前体溶解在无钙克林布氏林格氏缓冲液（G'= 1141±23 Pa）中，则与在培养基中稀释的那些（G'= 213±19 Pa）相比，水凝胶的机械性能更高。刺激的水凝胶中的细胞比未刺激的培养物（32％）更圆（55％）（p = 0.005）。与对照相比，刺激水凝胶中的软骨生成标记（例如SOX-9和聚集蛋白聚糖）更高。ES表明，受刺激样品中糖胺聚糖和胶原蛋白相对于DNA的标准化含量略高。另外，归一化为总胶原的II型胶原在刺激的水凝胶中要高2.43倍。这些发现使ES通过结合水凝胶和MSC成为增强关节软骨组织工程结果的有前途的工具。