静电相互作用控制细胞外囊泡在支持的脂质双层上的吸附,Journal of Colloid and Interface Science

位于生物体不同部位的细胞之间的通讯通常由膜包裹的纳米颗粒介导，例如细胞外囊泡（EV）。EV 结合和细胞摄取机制取决于 EV 膜的异质组成。从胶体的角度来看，EV膜通过特异性和非特异性相互作用与其他生物界面相互作用，其中后者包括长程静电力和范德华力，以及短程排斥“空间水合”力。虽然大多数 EV 固定方案通常都利用静电力，但各种胶体力在控制 EV 在表面吸附方面所发挥的作用尚未得到彻底解决。在目前的工作中，我们结合石英晶体微天平和耗散监测（QCM-D）和共焦激光扫描显微镜（CLSM）研究了EV在携带不同表面电荷密度的支撑脂质双层（SLB）上的吸附。我们证明，EV 在脂质膜上的吸附可以通过改变静电力的强度来控制，并且我们在非线性泊松-玻尔兹曼理论的框架内理论上描述了观察到的现象。我们的建模结果证实了实验观察结果，并强调了吸引静电在 EV 吸附到脂质膜上所起的关键作用。他们还表明，为模型脂质系统开发的简化理论可以成功应用于其生物类似物的研究，并为 EV 膜相互作用提供新的基本见解，并有可能用于开发新型 EV 分离和固定策略。

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Communication between cells located in different parts of an organism is often mediated by membrane-enveloped nanoparticles, such as extracellular vesicles (EVs). EV binding and cell uptake mechanisms depend on the heterogeneous composition of the EV membrane. From a colloidal perspective, the EV membrane interacts with other biological interfaces via both specific and non-specific interactions, where the latter include long-ranged electrostatic and van der Waals forces, and short-ranged repulsive “steric-hydration” forces. While electrostatic forces are generally exploited in most EV immobilization protocols, the roles played by various colloidal forces in controlling EV adsorption on surfaces have not yet been thoroughly addressed. In the present work, we study the adsorption of EVs onto supported lipid bilayers (SLBs) carrying different surface charge densities using a combination of quartz crystal microbalance with dissipation monitoring (QCM-D) and confocal laser scanning microscopy (CLSM). We demonstrate that EV adsorption onto lipid membranes can be controlled by varying the strength of electrostatic forces and we theoretically describe the observed phenomena within the framework of nonlinear Poisson-Boltzmann theory. Our modelling results confirm the experimental observations and highlight the crucial role played by attractive electrostatics in EV adsorption onto lipid membranes. They furthermore show that simplified theories developed for model lipid systems can be successfully applied to the study of their biological analogues and provide new fundamental insights into EV-membrane interactions with potential use in developing novel EV separation and immobilization strategies.