Amore-Pacific Co. R&D Center , Yongin 17074 , Republic of Korea.
ACS Appl Mater Interfaces. 2019 May 22;11(20):18817-18824. doi: 10.1021/acsami.8b22223. Epub 2019 May 10.
We report a tungsten disulfide (WS) nanosheet-immobilized hydrogel system that can inhibit oxidative stress on living cells. First, we fabricated a highly stable suspension of WS nanosheets as a radical scavenger by enveloping them with the amphiphilic poly(ε-caprolactone)- b-poly(ethylene oxide) copolymer (PCL- b-PEO) during in situ liquid exfoliation in aqueous medium. After the PCL- b-PEO-enveloped WS nanosheets were embedded in three types of hydrogel systems, including carrageenan gum/locust bean gum bulk hydrogels, physically cross-linked alginate microparticles, and covalently cross-linked PEG hydrogel microparticles, they retained their characteristic optical properties. Intriguingly, the WS nanosheet-immobilized hydrogel particles exhibited sustainable radical scavenging performance without any deterioration in the original activity of the WS nanosheets, even after repeated use. This implies that the hydrogen atoms dissociated from the chalcogen of the WS nanosheets effectively scavenged free radicals through the hydrogel mesh. Because of this unique behavior, the coexistence of the WS nanosheets with living cells in the hydrogel matrix improved cell viability up to 40%, which demonstrates that the WS nanosheets can suppress oxidative stress on living cells.
我们报告了一种二硫化钨（WS）纳米片固定水凝胶系统，它可以抑制活细胞的氧化应激。首先，我们通过在水介质中的原位液相剥离过程中用两亲性聚（ε-己内酯）-b-聚（氧化乙烯）共聚物（PCL-b-PEO）包裹 WS 纳米片，制备了一种具有高稳定性的 WS 纳米片悬浮液作为自由基清除剂。PCL-b-PEO 包裹的 WS 纳米片嵌入三种水凝胶系统中，包括卡拉胶/槐豆胶块状水凝胶、物理交联的海藻酸盐微球和化学交联的 PEG 水凝胶微球后，保留了其特征光学性质。有趣的是，WS 纳米片固定的水凝胶颗粒表现出可持续的自由基清除性能，而 WS 纳米片的原始活性没有任何恶化，即使在重复使用后也是如此。这意味着 WS 纳米片的硫属元素上解离的氢原子通过水凝胶网有效地清除自由基。由于这种独特的行为，WS 纳米片与活细胞共存于水凝胶基质中，使细胞存活率提高了 40%，这表明 WS 纳米片可以抑制活细胞的氧化应激。
