Understanding the mechanical behaviors of nanoparticles confined between adjacent cells is of fundamental importance to the passage of drug cargoes through cell junctions, where the nanoparticles could have contact with two cell membranes simultaneously. Here we theoretically investigate the adhesive membrane wrapping and trapping of rigid cylindrical and spherical nanoparticles confined by two cell membranes. It is shown that the system energy and configurations depend collectively on the membrane bending rigidity, tension, adhesion energy, and the ratio between the particle size and intermembrane distance. Two fundamental modes of particle–membrane interaction are revealed, two-membrane trapping and single-membrane wrapping. Confined cylindrical nanoparticles remain trapped by two cell membranes and confined spherical nanoparticles could undergo a state transition from two-membrane trapping to single-membrane wrapping as the wrapping degree increases. Corresponding interaction phase diagrams for cylindrical and spherical nanoparticles are established based on the stability of no-wrapping, partial-trapping, partial-wrapping, full-trapping and full-wrapping states. Analytical predictions are also obtained in characterizing the single-membrane wrapping at early wrapping degree. Our results suggest that cylindrical nanoparticles in comparison with spherical nanoparticles might display superior drug penetration in tumors and across epithelial and endothelial barriers, providing guidance in the rational design of anticancer nanomedicine.

理解限制在相邻细胞之间的纳米颗粒的机械行为对于药物通过细胞连接处的传递至关重要，在这种情况下，纳米颗粒可以同时与两个细胞膜接触。在这里，我们理论上研究由两个细胞膜限制的刚性圆柱和球形纳米颗粒的粘性膜包裹和捕获。结果表明，系统能量和构型共同取决于膜的弯曲刚度，张力，粘附能以及粒径与膜间距离的比值。揭示了颗粒-膜相互作用的两种基本模式，即两膜捕获和单膜包裹。受限的圆柱形纳米颗粒仍然被两个细胞膜捕获，并且随着包裹度的增加，球形的纳米颗粒可能会发生从两膜捕获到单膜包裹的状态转变。基于无包裹状态，部分包裹状态，部分包裹状态，完全包裹状态和完全包裹状态的稳定性，建立了圆柱状和球形纳米颗粒的相应相互作用相图。在早期包裹程度表征单膜包裹方面也获得了分析预测。我们的研究结果表明，与球形纳米颗粒相比，圆柱形纳米颗粒可能在肿瘤以及跨越上皮和内皮屏障方面显示出更高的药物渗透性，为抗癌纳米药物的合理设计提供了指导。