Self-Etching of Metal-Organic Framework Templates during Polydopamine Coating: Nonspherical Polydopamine Capsules and Potential Intracellular Trafficking of Metal Ions.
Self-Etching of Metal-Organic Framework Templates during Polydopamine Coating: Nonspherical Polydopamine Capsules and Potential Intracellular Trafficking of Metal Ions.
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DOI：
10.1021/acs.langmuir.7b02811
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发表时间：
2017-09
期刊：
影响因子：
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通讯作者：
Zihan Ye;Song-hai Wu;C. Zheng;Lu Yang;Pengjiao Zhang;Zhenkun Zhang
中科院分区：
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作者：
Zihan Ye;Song-hai Wu;C. Zheng;Lu Yang;Pengjiao Zhang;Zhenkun Zhang
传统上，用钢或其他金属制成的容器不适合泡茶，可能是因为茶中的多酚成分可以与金属离子螯合。本文所报告的观察结果背后可能有类似的原因。通过ph诱导多巴胺的自聚合，我们在定义良好的金属有机框架（MOF）晶体颗粒上涂覆了聚多巴胺（PDA），我们发现MOF模板在涂覆过程中会自动蚀刻掉，产生继承模板形态的非球形PDA胶囊。这种MOF模板的自蚀刻归因于MOF的金属节点被PDA层中的儿茶酚基团螯合。此外，具有截断立方形状的沸石咪唑酸框架-8 （ZIF-8）的自蚀刻可能遵循晶体面依赖的方式，导致在高度生物相容性的PDA壳内具有各种形状的ZIF-8产物的中间蛋黄壳结构。将这种中间杂交颗粒与癌变的HeLa细胞系孵育可导致明显的细胞毒性，这初步与ZIF@PDA纳米颗粒的细胞内化有关，因为PDA层具有细胞亲和性。随后，被封装的ZIF-8在细胞内的自蚀刻使Zn2+不断释放，使细胞内的Zn2+增加到有害的水平。因此，金属离子在细胞内的传递有可能实现，这可能为癌症治疗提供一种新的途径。
Traditionally, containers made from steel or other metals are not good for making tea, probably due to the fact that polyphenol components in tea can chelate with metal ions. A similar reason might stand behind the observations as reported herein. During the coating of well-defined metal-organic framework (MOF) crystalline particles with polydopamine (PDA) via pH-induced self-polymerization of dopamine, we found that MOF templates automatically etch off during the coating, giving rise to nonspherical PDA capsules that inherit the morphologies of the templates. Such self-etching of MOF templates is ascribed to the chelation of the metal nodes of the MOFs by the catechol moieties in the PDA layer. In addition, the self-etching of the zeolitic imidazolate framework-8 (ZIF-8) with a truncated cubic shape probably follows a crystalline facet-dependent fashion, resulting in intermediate yolk-shell structures with ZIF-8 cargos of various shapes inside a highly biocompatible PDA shell. Incubation of such intermediate hybrid particles with the cancerous HeLa cell line leads to pronounced cytotoxicity, which is tentatively connected with the cellular internalization of the ZIF@PDA nanoparticles because of the cell affinity of the PDA layer. Subsequently, the continuous release of Zn2+ by the self-etching of the encapsulated ZIF-8 inside the cell increases intracellular Zn2+ to a harmful level. Therefore, intracellular delivery of metal ions is probably realized, which might offer a novel way for cancer therapy.