生物相容性抗菌丝胶蛋白-铜纳米酶的制备与性能研究

文章以 Cu(Ⅱ) 螯合改性蚕丝丝胶蛋白（silk sericin，SS），制备一种具有类过氧化物酶（POD）活性的 Cu@SS，以实现丝胶蛋白的再利用；并研究 Cu(Ⅱ) 对丝胶蛋白结构的影响，以及 Cu@SS 纳米酶的催化性能、生物相容性和抗菌活性。结果表明，Cu@SS 纳米酶具有类 POD 活性，以 3,3',5,5'-四甲基联苯胺（TMB）和过氧化氢（ $ H_{2}O_{2} $）为底物，Cu@SS 催化反应的米氏常数（ $ K_{m} $）分别为 $ 1.965 \times 10^{-4} $、 $ 1.238 \times 10^{-3} $ mol/L；细胞实验结果表明，Cu@SS 纳米酶具有良好的生物相容性，对巨噬细胞 RAW 264.7 无细胞毒性。此外，在 $ H_{2}O_{2} $ 存在下，Cu@SS 纳米酶可以使大肠杆菌（Escherichia coli）的相对存活率下降至 45%。因此，Cu@SS 纳米酶具有良好的生物相容性和良好的抗菌性能。

In this study, silk sericin(SS) was modified by Cu(II) chelation to prepare Cu@SS with peroxidase (POD)-like activity for the reuse of sericin. The effect of Cu(II) on the structure of sericin and the catalytic performance, biocompatibility and antibacterial activity of Cu@SS nanozymes were studied. The results showed that Cu@SS nanozymes had POD-like activity, and their Michaelis constants ( $ K_{m} $) for 3,3',5,5'-tetramethylbenzidine(TMB) and hydrogen peroxide( $ H_{2}O_{2} $) were $ 1.965 \times 10^{-4} $ mol/L and $ 1.238 \times 10^{-3} $ mol/L, respectively. Cell experiments showed that Cu@SS nanozymes had good biocompatibility and no cytotoxicity against macrophage RAW 264.7 cells. Furthermore, Cu@SS nanozymes reduced the relative bacterial viability of Escherichia coli to 45% in the presence of $ H_{2}O_{2} $. Therefore, Cu@SS nanozyme is a good biocompatible material with favorable antibacterial properties.