Size-dependent phagocytosis is a well-characterized phenomenon in monocytes and macrophages. However, this size effect for preferential gene delivery to these important cell targets has not been fully exploited because commonly adopted stabilization methods for electrostatically complexed nucleic acid nanoparticles, such as PEGylation and charge repulsion, typically arrest the vehicle size below 200 nm. Here, we bridge the technical gap in scalable synthesis of larger submicron gene delivery vehicles by electrostatic self-assembly of charged nanoparticles, facilitated by a polymer structurally designed to modulate internanoparticle Coulombic and van der Waals forces. Specifically, our strategy permits controlled assembly of small poly(β-amino ester)/messenger ribonucleic acid (mRNA) nanoparticles into particles with a size that is kinetically tunable between 200 and 1,000 nm with high colloidal stability in physiological media. We found that assembled particles with an average size of 400 nm safely and most efficiently transfect monocytes following intravenous administration and mediate their differentiation into macrophages in the periphery. When a CpG adjuvant is co-loaded into the particles with an antigen mRNA, the monocytes differentiate into inflammatory dendritic cells and prime adaptive anticancer immunity in the tumor-draining lymph node. This platform technology offers a unique ligand-independent, particle-size-mediated strategy for preferential mRNA delivery and enables therapeutic paradigms via monocyte programming.

中文翻译：

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聚阳离子/mRNA纳米颗粒的超分子组装和体内单核细胞编程


大小依赖性吞噬作用是单核细胞和巨噬细胞中一种明确的现象。然而，这种优先将基因递送到这些重要细胞靶标的尺寸效应尚未得到充分利用，因为静电复合核酸纳米粒子常用的稳定方法（例如聚乙二醇化和电荷排斥）通常将载体尺寸限制在 200 nm 以下。在这里，我们通过带电纳米粒子的静电自组装来弥补较大亚微米基因递送载体的可扩展合成的技术差距，这由结构设计用于调节纳米粒子间库仑力和范德华力的聚合物促进。具体来说，我们的策略允许将小的聚（β-氨基酯）/信使核糖核酸（mRNA）纳米颗粒受控组装成尺寸在200至1,000 nm之间动力学可调的颗粒，并在生理介质中具有高胶体稳定性。我们发现，平均尺寸为 400 nm 的组装颗粒在静脉注射后可以安全且最有效地转染单核细胞，并介导其分化为外周巨噬细胞。当 CpG 佐剂与抗原 mRNA 共同加载到颗粒中时，单核细胞分化为炎性树突状细胞，并在肿瘤引流淋巴结中启动适应性抗癌免疫。该平台技术提供了一种独特的不依赖配体、粒径介导的策略，用于优先 mRNA 递送，并通过单核细胞编程实现治疗范例。