Customizable gold nanoparticle platforms are motivating innovations in drug discovery with massive therapeutic potential due to their biocompatibility, stability, and imaging capabilities. Further development requires the understanding of how discrete differences in shape, charge, or surface chemistry affect the drug delivery process of the nanoparticle. The nanoparticle shape can have a significant impact on nanoparticle function as this can, for example, drastically change the surface area available for modifications, such as surface ligand density. In order to investigate the effects of nanoparticle shape on the structure of cell membranes, we directly probed nanoparticle–lipid interactions with an interface sensitive technique termed sum frequency generation (SFG) vibrational spectroscopy. Both gold nanostars and gold nanospheres with positively charged ligands were allowed to interact with a model cell membrane and changes in the membrane structure were directly observed by specific SFG vibrational modes related to molecular bonds within the lipids. The SFG results demonstrate that the +Au nanostars both penetrated and impacted the ordering of the lipids that made up the membrane, while very little structural changes to the model membrane were observed by SFG for the +Au nanospheres interacting with the model membrane. This suggests that the +Au nanostars, compared to the +Au nanospheres, are more disruptive to a cell membrane. Our findings indicate the importance of shape in nanomaterial design and provide strong evidence that shape does play a role in defining nanomaterial-biological interactions.

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形状依赖的金纳米颗粒与模型细胞膜的相互作用

可定制的金纳米颗粒平台由于其生物相容性、稳定性和成像能力，正在推动药物发现领域的创新，具有巨大的治疗潜力。进一步的开发需要了解形状、电荷或表面化学的离散差异如何影响纳米颗粒的药物输送过程。纳米颗粒的形状可以对纳米颗粒的功能产生重大影响，因为这可以例如极大地改变可用于修饰的表面积，例如表面配体密度。为了研究纳米颗粒形状对细胞膜结构的影响，我们使用称为和频发生（SFG）振动光谱的界面敏感技术直接探测纳米颗粒与脂质的相互作用。金纳米星和带正电荷配体的金纳米球都可以与模型细胞膜相互作用，并且通过与脂质内分子键相关的特定 SFG 振动模式直接观察到膜结构的变化。SFG 结果表明，+Au 纳米星穿透并影响构成膜的脂质的排序，而 SFG 观察到+Au 纳米球与模型膜相互作用时模型膜的结构变化非常小。这表明，与+Au纳米球相比，+Au纳米星对细胞膜更具破坏性。我们的研究结果表明了形状在纳米材料设计中的重要性，并提供了强有力的证据表明形状确实在定义纳米材料-生物相互作用中发挥着作用。