Understanding and controlling the interaction between nanoparticles and biological entities is fundamental to the development of nanomedicine applications. In particular, the possibility to realize nanoparticles capable of directly targeting neutral lipid membranes would be advantageous to numerous applications aiming at delivering nanoparticles and their cargos into cells and biological vesicles. Here, we use experimental and computational methodologies to analyze the interaction between liposomes and gold nanoparticles (AuNPs) featuring cationic headgroups in their protecting monolayer. We find that in contrast to nanoparticles decorated with other positively charged headgroups, guanidinium-coated AuNPs can bind to neutral phosphatidylcholine liposomes, inducing nondisruptive membrane permeabilization. Atomistic molecular simulations reveal that this ability is due to the multivalent H-bonding interaction between the phosphate residues of the liposome’s phospholipids and the guanidinium groups. Our results demonstrate that the peculiar properties of arginine magic, an effect responsible for the membranotropic properties of some naturally occurring peptides, are also displayed by guanidinium-bearing functionalized AuNPs.

了解和控制纳米粒子与生物实体之间的相互作用是纳米医学应用发展的基础。特别是，实现能够直接靶向中性脂质膜的纳米粒子的可能性将有利于许多旨在将纳米粒子及其货物输送到细胞和生物囊泡中的应用。在这里，我们使用实验和计算方法来分析脂质体和金纳米粒子 (AuNP) 之间的相互作用，金纳米粒子在其保护单层中具有阳离子头基。我们发现，与装饰有其他带正电荷的头基团的纳米粒子相比，胍涂层的 AuNPs 可以与中性磷脂酰胆碱脂质体结合，诱导不破坏膜透化。原子分子模拟表明，这种能力是由于脂质体磷脂的磷酸盐残基与胍基团之间的多价氢键相互作用所致。我们的结果表明，精氨酸魔法的奇特特性，一种导致某些天然存在的肽的促膜特性的效应，也被带有胍盐的功能化 AuNP 所展示。