ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Drug Delivery, Disposition and Dynamics Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia.
J Mater Chem B. 2020 May 7;8(17):3896-3907. doi: 10.1039/c9tb02614b. Epub 2020 Mar 30.
Inspired by the properties of the naturally occurring HS donor, diallyl trisulfide (DATS, extracted from garlic), the biological behaviour of trisulfide-bearing PEG-conjugates was explored. Specifically, three conjugates comprising an mPEG tail and a cholesteryl head were investigated: conjugates bridged by a trisulfide linker (T), a disulfide linker (D) or a carbamate linker (C), and a fourth comprising two mPEG tails bridged by a trisulfide linker (P). HS testing using both a fluorescent chemical probe in HEK293 cells and an amperometric sensor to monitor release in suspended cells, demonstrated the ability of the trisulfide conjugates, T and P, to release HS in the presence of cellular thiols. Cytotoxicity and cyto-protective capacity on HEK293 cells showed that T was the best tolerated of the conjugates studied, and remarkably more so than D or C. Moreover, it was noted that application of T conferred a protective effect to the cells, effectively abolishing the toxicity associated with co-administered C. The interaction of conjugates and combinations thereof with the cell membrane of HEK cells, as well as ROS generation were also investigated. It was found that C caused significant membrane perturbation, correlating with high losses in cell viability and pronounced generation of ROS, especially in the mitochondria. T, however, did not disturb the membrane and was able to mitigate the generation of ROS, especially in the mitochondria. The interplay of the cholesteryl group and HS donation for conferring cytoprotective effects was clearly demonstrated as P did not display the same beneficial characteristics as T.
受天然 HS 供体二烯丙基三硫化物 (DATS，从大蒜中提取) 性质的启发，研究了含三硫键的 PEG 缀合物的生物学行为。具体来说，研究了三种含有 mPEG 尾巴和胆固醇头部的缀合物：由三硫键连接体 (T)、二硫键连接体 (D) 或碳酸酯连接体 (C) 桥接的缀合物，以及由两个 mPEG 尾巴通过三硫键桥接的第四个缀合物 (P)。使用 HEK293 细胞中的荧光化学探针和安培传感器监测悬浮细胞中释放物的 HS 测试表明，三硫键缀合物 T 和 P 能够在细胞硫醇存在下释放 HS。对 HEK293 细胞的细胞毒性和细胞保护能力的研究表明，T 是研究中耐受性最好的缀合物，比 D 或 C 好得多。此外，值得注意的是，T 的应用对细胞具有保护作用，有效地消除了与联合施用 C 相关的毒性。还研究了缀合物及其与 HEK 细胞细胞膜的相互作用以及 ROS 的产生。结果发现，C 导致显著的膜扰动，与细胞活力的显著降低和 ROS 的明显产生相关，尤其是在线粒体中。然而，T 不会干扰膜，并且能够减轻 ROS 的产生，尤其是在线粒体中。胆固醇基团和 HS 供体相互作用赋予细胞保护作用，这一点得到了清楚的证明，因为 P 没有显示出与 T 相同的有益特征。
