Selective RNA delivery is required for the broad implementation of RNA clinical applications, including prophylactic and therapeutic vaccinations, immunotherapies for cancer, and genome editing. Current polyanion delivery relies heavily on cationic amines, while cationic guanidinium systems have received limited attention due in part to their strong polyanion association, which impedes intracellular polyanion release. Here, we disclose a general solution to this problem in which cationic guanidinium groups are used to form stable RNA complexes upon formulation but at physiological pH undergo a novel charge-neutralization process, resulting in RNA release. This new delivery system consists of guanidinylated serinol moieties incorporated into a charge-altering releasable transporter (GSer-CARTs). Significantly, systematic variations in structure and formulation resulted in GSer-CARTs that exhibit highly selective mRNA delivery to the lung (∼97%) and spleen (∼98%) without targeting ligands. Illustrative of their breadth and translational potential, GSer-CARTs deliver circRNA, providing the basis for a cancer vaccination strategy, which in a murine model resulted in antigen-specific immune responses and effective suppression of established tumors.

中文翻译：

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使用胍基化丝氨醇电荷改变可释放转运蛋白在体内选择性地递送 mRNA


RNA临床应用的广泛实施需要选择性RNA递送，包括预防性和治疗性疫苗接种、癌症免疫疗法和基因组编辑。目前的聚阴离子递送严重依赖于阳离子胺，而阳离子胍系统受到的关注有限，部分原因是其强的聚阴离子缔合，阻碍了细胞内聚阴离子的释放。在这里，我们公开了该问题的通用解决方案，其中阳离子胍基团用于在配制时形成稳定的RNA复合物，但在生理pH下经历新的电荷中和过程，导致RNA释放。这种新的递送系统由并入电荷改变可释放转运蛋白（GSer-CART）中的胍基化丝氨醇部分组成。值得注意的是，结构和配方的系统变化导致 GSer-CART 在没有靶向配体的情况下表现出高度选择性的 mRNA 递送至肺 (~97%) 和脾 (~98%)。 GSer-CART 可以传递 circRNA，为癌症疫苗接种策略提供基础，这说明了其广度和转化潜力，该策略在小鼠模型中导致了抗原特异性免疫反应并有效抑制已形成的肿瘤。