In this contribution, an injectable hydrogel was developed with chitosan, gelatin, β-glycerphosphate and Arg-Gly-Asp (RGD) peptide: this hydrogel is liquid in room temperature and rapidly gels at 37 °C; RGD peptide promises better growth microenvironment for various cells, especially endothelial cells (EC), smooth muscle cells (SMC) and mesenchymal stem cells (MSC). Both stromal cell-derived factor-1 (SDF-1) nanoparticle and vascular endothelial growth factor (VEGF) nanoparticles were loaded in the injectable hydrogel to simulate the natural nanoparticles in the extracellular matrix (ECM) to promote angiogenesis. In vitro EC/SMC and MSC/SMC co-culture experiment indicated that the nanocomposite hydrogel accelerated constructing embryonic form of blood vessels, and chick embryo chorioallantoic membrane model demonstrated its ability of improving cells migration and blood vessel regeneration. We injected this nanocomposite hydrogel into rat myocardial infarction (MI) model and the results indicated that the rats heart function recovered better compared control group. We hope this injectable nanocomposite hydrogel may possess wider application in tissue engineering.

中文翻译：

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潜在应用的血管化和组织修复的可注射纳米复合水凝胶。

为此，开发了一种可注射水凝胶，其中含有壳聚糖，明胶，β-甘油磷酸酯和Arg-Gly-Asp（RGD）肽：这种水凝胶在室温下呈液态，在37°C时迅速凝胶化；RGD肽有望为各种细胞，尤其是内皮细胞（EC），平滑肌细胞（SMC）和间充质干细胞（MSC）提供更好的生长微环境。将基质细胞衍生因子1（SDF-1）纳米颗粒和血管内皮生长因子（VEGF）纳米颗粒都装入可注射水凝胶中，以模拟细胞外基质（ECM）中的天然纳米颗粒以促进血管生成。体外EC / SMC和MSC / SMC共培养实验表明，纳米复合水凝胶促进了血管胚胎形式的构建，鸡胚绒膜尿囊膜模型显示了其改善细胞迁移和血管再生的能力。我们将这种纳米复合水凝胶注入大鼠心肌梗死（MI）模型中，结果表明，与对照组相比，大鼠的心脏功能恢复更好。我们希望这种可注射的纳米复合水凝胶在组织工程中具有更广泛的应用。