The benefits of combined cell/material therapy appear promising for myocardial infarction treatment. The safety of alginate, along with its excellent biocompatibility and biodegradability, has been extensively investigated for cardiac tissue engineering. Among graphene-based nanomaterials, reduced graphene oxide has been considered as a promising candidate for cardiac treatment due to its unique physicochemical properties. In this study, the reduced graphene oxide incorporation effect within alginate hydrogels was investigated for cardiac repair application. Reduced graphene oxide reinforced alginate properties, resulting in an increase in gel stiffness. The cytocompatibility of the hydrogels prepared with human bone marrow–derived mesenchymal stem cells was assessed by the 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) assay. Following reduced graphene oxide addition, alginate-reduced graphene oxide retained significantly higher cell viability compared to that of alginate and cells cultured on tissue culture plates. Acridine orange/propidium iodide staining was also used to identify both viable and necrotic human bone marrow–derived mesenchymal stem cells within the prepared hydrogels. After a 72-h culture, the percentage of viable cells was twice as much as those cultured on either alginate or tissue culture plate, reaching approximately 80%. Quantitative reverse transcription polymerase chain reaction analysis was performed to assess gene expression of neonatal rat cardiac cells encapsulated on hydrogels for TrpT-2, Conx43, and Actn4 after 7 days. The expression of all genes in alginate-reduced graphene oxide increased significantly compared to that in alginate or tissue culture plate. The results obtained confirmed that the presence of reduced graphene oxide, as an electro-active moiety within alginate, could tune the physicochemical properties of this material, providing a desirable electroactive hydrogel for stem cell therapy in patients with ischemic heart disease.

中文翻译：

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还原氧化石墨烯促进海藻酸盐在心脏修复中的生物相容性

细胞/材料联合疗法的益处似乎对心肌梗塞治疗很有希望。海藻酸盐的安全性及其优异的生物相容性和生物降解性，已被广泛研究用于心脏组织工程。在基于石墨烯的纳米材料中，还原氧化石墨烯由于其独特的物理化学性质而被认为是心脏治疗的有希望的候选者。在这项研究中，研究了在海藻酸盐水凝胶中减少氧化石墨烯的掺入效应，以用于心脏修复应用。减少的氧化石墨烯增强了海藻酸盐的特性，从而增加了凝胶刚度。用人骨髓间充质干细胞制备的水凝胶的细胞相容性通过 3-（4,5 二甲基噻唑-2-基）-2,5-二苯基溴化四唑）测定进行评估。在减少氧化石墨烯添加后，与藻酸盐和在组织培养板上培养的细胞相比，藻酸盐还原的氧化石墨烯保留了显着更高的细胞活力。吖啶橙/碘化丙啶染色也用于鉴定制备的水凝胶中的活的和坏死的人骨髓间充质干细胞。培养 72 小时后，活细胞的百分比是在海藻酸盐或组织培养板上培养的细胞百分比的两倍，达到约 80%。进行定量逆转录聚合酶链反应分析，以评估包裹在 TrpT-2、Conx43 和 Actn4 水凝胶上的新生大鼠心脏细胞在 7 天后的基因表达。与藻酸盐或组织培养板相比，藻酸盐还原氧化石墨烯中所有基因的表达显着增加。获得的结果证实，还原氧化石墨烯的存在，作为藻酸盐中的电活性部分，可以调整这种材料的理化性质，为缺血性心脏病患者的干细胞治疗提供理想的电活性水凝胶。