DataSheet1_Microfluidic one-step synthesis of a metal−organic framework for osteoarthritis therapeutic microRNAs delivery.docx

As a class of short non-coding ribonucleic acids (RNAs), microRNAs (miRNA) regulate gene expression in human cells and are expected to be nucleic acid drugs to regulate and treat a variety of biological processes and diseases. However, the issues with potential materials toxicity, quantity production, poor cellular uptake, and endosomal entrapment limit their further applications in clinical practice. Herein, ZIF-8, a metal-organic framework with noncytotoxic zinc (II) as the metal coordination center, was selected as miRNA delivery vector was used to prepare miR-200c-3p@ZIF-8 in one step by Y-shape microfluidic chip to achieve intracellular release with low toxicity, batch size, and efficient cellular uptake. The obtained miR-200c-3p@ZIF-8 was identified by TEM, particle size analysis, XRD, XPS, and zeta potential. Compared with the traditional hydrothermal method, the encapsulation efficiency of miR-200c-3p@ZIF-8 prepared by the microfluidic method is higher, and the particle size is more uniform and controllable. The experimental results in cellular level verified that the ZIF-8 vectors with low cytotoxicity and high miRNAs loading efficiency could significantly improve cellular uptake and endosomal escape of miRNAs, providing a robust and general strategy for nucleic acid drug delivery. As a model, the prepared miR-200c-3p@ZIF-8 is confirmed to be effective in osteoarthritis treatment.

作为一类短链非编码核糖核酸（ribonucleic acids，RNAs），微小RNA（microRNAs，miRNA）可调控人体细胞内的基因表达，有望作为核酸药物（nucleic acid drugs）调控并治疗多种生物过程与疾病。然而，材料潜在毒性、量产瓶颈、细胞摄取效率低下以及内体捕获等问题，限制了其在临床实践中的进一步应用。据此，本研究选用以无细胞毒性的锌(II)作为金属配位中心的金属有机框架（metal-organic framework）ZIF-8作为miRNA递送载体，通过Y型微流控芯片（Y-shape microfluidic chip）一步制备得到miR-200c-3p@ZIF-8，可实现低毒性、批次可控且细胞摄取高效的胞内释放。所制备的miR-200c-3p@ZIF-8通过透射电子显微镜（Transmission Electron Microscopy，TEM）、粒径分析、X射线衍射（X-ray Diffraction，XRD）、X射线光电子能谱（X-ray Photoelectron Spectroscopy，XPS）以及ζ电位表征进行了鉴定。与传统水热法（hydrothermal method）相比，微流控法制备的miR-200c-3p@ZIF-8具有更高的包封率，且粒径更为均匀可控。细胞水平的实验结果证实，具备低细胞毒性与高miRNA负载效率的ZIF-8载体可显著提升miRNA的细胞摄取能力与内体逃逸效率，为核酸药物递送提供了一种可靠且通用的策略。作为模型体系，所制备的miR-200c-3p@ZIF-8被证实可有效治疗骨关节炎（osteoarthritis）。