Chen Mingjia, Sun Wen, Kretzschmann Annika, Butt Hans-Jürgen, Wu Si
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany; State Key Laboratory of Fine Chemicals, Dalian University of Technology, 2 Linggong Road, 116024 Dalian, China.
J Inorg Biochem. 2020 Jun;207:111052. doi: 10.1016/j.jinorgbio.2020.111052. Epub 2020 Mar 9.
Photoactivatable ruthenium (Ru) complexes are promising compounds for anticancer phototherapy. They must be stable under physiological conditions before they are transported to cancer cells. In this paper, we systematically studied the stabilities of two Ru-containing block copolymers (Ru complexes as side group or in main chain, respectively) and their corresponding Ru complexes in different media, including saline, bovine serum albumin (BSA) solution, Dulbecco's Modified Eagle's Medium (DMEM, pH 6.5) and DMEM (pH 5.5) with 1.0 mM glutathione (GSH). Their stabilities were studied by monitoring the metal-to-ligand charge transfer (MLCT) bands of the Ru moieties via UV-Vis absorption spectroscopy. The MLCT bands of Ru complexes changed to varying degrees within a day in the above-mentioned media, indicating that they were instable. In contrast, the MLCT bands of Ru-containing polymer assemblies did not change significantly under the same conditions. These results showed that the self-assembled nanostructures protected the Ru moieties and improved their stability. In addition, these nanostructured polymer assemblies could be activated by red light. Therefore, the studied Ru-containing polymer assemblies are more suitable for in vivo applications than their low-molecular weight analogues.
光可激活钌（Ru）配合物是用于抗癌光疗的有前景的化合物。在它们被转运到癌细胞之前，必须在生理条件下保持稳定。在本文中，我们系统地研究了两种含钌嵌段共聚物（Ru配合物分别作为侧基或在主链中）及其相应的Ru配合物在不同介质中的稳定性，这些介质包括盐水、牛血清白蛋白（BSA）溶液、杜尔贝科改良伊格尔培养基（DMEM，pH 6.5）以及含有1.0 mM谷胱甘肽（GSH）的DMEM（pH 5.5）。通过紫外可见吸收光谱监测Ru部分的金属 - 配体电荷转移（MLCT）带，研究了它们的稳定性。在上述介质中，Ru配合物的MLCT带在一天内有不同程度的变化，表明它们不稳定。相比之下，含Ru聚合物组装体的MLCT带在相同条件下没有明显变化。这些结果表明，自组装纳米结构保护了Ru部分并提高了它们的稳定性。此外，这些纳米结构聚合物组装体可以被红光激活。因此，所研究的含Ru聚合物组装体比它们的低分子量类似物更适合体内应用。
