Digiacomo Luca, Renzi Serena, Pirrottina Andrea, Amenitsch Heinz, De Lorenzi Valentina, Pozzi Daniela, Cardarelli Francesco, Caracciolo Giulio
NanoDelivery Lab, Department of Molecular Medicine, Sapienza University of Rome, 00161 Rome, Italy.
Institute of Inorganic Chemistry, Graz University of Technology, 8010 Graz, Austria.
ACS Pharmacol Transl Sci. 2024 Sep 5;7(10):3004-3010. doi: 10.1021/acsptsci.4c00419. eCollection 2024 Oct 11.
Polyethylene glycol (PEG) is a common surface modification for lipid nanoparticles (LNPs) to improve their stability and in vivo circulation time. However, the impact of PEGylation on LNP cellular uptake remains poorly understood. To tackle this issue, we systematically compared plain and PEGylated LNPs by combining dynamic light scattering, electrophoretic light scattering, and synchrotron small-angle X-ray scattering (SAXS) that unveils a striking similarity in size and core structure but a significant reduction in surface charge. Upon administration to human embryonic kidney (HEK 293) cells, plain and PEGylated LNPs were internalized through different endocytic routes, as revealed by spatiotemporal correlation spectroscopy. An imaging-derived mean square displacement (iMSD) analysis shows that PEGylated LNPs exhibit a significantly stronger preference for caveolae-mediated endocytosis (CAV) and clathrin-mediated endocytosis (CME) pathways compared to plain LNPs, with these latter being better tailored to MCR-dependent internalization and trafficking. This suggests that PEG plays a crucial role in directing LNPs toward specific cellular uptake routes. Further studies should explore how PEG-mediated endocytosis impacts intracellular trafficking and ultimately translates to therapeutic efficacy, guiding the design of next-generation LNP delivery systems.
聚乙二醇（PEG）是脂质纳米颗粒（LNPs）常用的表面修饰剂，可提高其稳定性和体内循环时间。然而，聚乙二醇化对LNP细胞摄取的影响仍知之甚少。为了解决这个问题，我们通过结合动态光散射、电泳光散射和同步加速器小角X射线散射（SAXS）系统地比较了普通LNP和聚乙二醇化LNP，结果显示它们在尺寸和核心结构上有惊人的相似性，但表面电荷显著降低。时空相关光谱显示，将普通LNP和聚乙二醇化LNP施用于人胚肾（HEK 293）细胞后，它们通过不同的内吞途径被内化。成像衍生的均方位移（iMSD）分析表明，与普通LNP相比，聚乙二醇化LNP对小窝介导的内吞作用（CAV）和网格蛋白介导的内吞作用（CME）途径表现出明显更强的偏好，而普通LNP更适合MCR依赖性内化和运输。这表明PEG在引导LNP走向特定的细胞摄取途径中起着关键作用。进一步的研究应探索PEG介导的内吞作用如何影响细胞内运输，并最终转化为治疗效果，从而指导下一代LNP递送系统的设计。
