Prompting immunostimulatory activity of curdlan with grafting methoxypolyethylene glycol

In this study, we used methoxypolyethylene glycol (mPEG) to modify CUR and unwind the triple helix structure to prompt the immunostimulatory activity. CUR-mPEG was synthesized through the substitution of hydroxides on CUR with mPEG-OH (Scheme 1). The physico-chemical properties of CUR-mPEG were characterized, including Fourier-transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic spectroscopy (1H-NMR), solubility, scanning electron microscopy (SEM), and Congo red tests. The release of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 from macrophages with the treatment of CUR-mPEG in vitro were assessed by enzyme-linked immunosorbent assay (ELISA). The cytotoxicity was characterized by CCK-8 and live/dead cell staining tests, and its antibacterial property was characterized by phagocytosis test.本研究采用甲氧基聚乙二醇（methoxypolyethylene glycol, mPEG）对姜黄素（Curcumin, CUR）进行修饰，并解开其三股螺旋结构，以增强其免疫刺激活性。CUR-mPEG通过将CUR上的羟基替换为mPEG-OH合成（方案1）。本研究对CUR-mPEG的理化性质进行了表征，包括傅里叶变换红外光谱（Fourier-transform infrared spectroscopy, FT-IR）、氢核磁共振波谱（hydrogen nuclear magnetic spectroscopy, ¹H-NMR）、溶解度测定、扫描电子显微镜（scanning electron microscopy, SEM）以及刚果红实验。采用酶联免疫吸附实验（enzyme-linked immunosorbent assay, ELISA）检测了体外经CUR-mPEG处理的巨噬细胞所释放的肿瘤坏死因子-α（tumor necrosis factor, TNF-α）与白细胞介素-6（interleukin, IL-6）水平。通过CCK-8法与活/死细胞染色实验表征其细胞毒性，并通过吞噬实验表征其抗菌性能。