了解和操纵异物和细胞膜之间的相互作用在细胞内和吞噬作用是至关重要的,不仅用于活细胞的命运,而且用于许多生物医学应用。本研究旨在阐明各向异性颗粒形状等变量的作用,曲率,定位,膜张力,在此基本过程中,使用最小的实验仿生系统,该系统包括巨大的单层囊泡和具有不同曲率和纵横比的杆状颗粒。我们发现,粒子包裹过程由弹性自由能损失和粘附自由能增益之间的平衡决定,导致两种不同的吞噬途径,尖端优先和侧面优先,强调粒子取向在确定路径中的重要性。此外,我们的实验结果与状态图中的理论预测一致,展示了如何通过膜张力和粘合强度之间的相互作用来控制从冲浪到部分包裹到完全包裹的包裹路径。在中等颗粒浓度下,我们观察到杆团的形成,表现出合作和顺序包装。我们的研究有助于通过强调各向异性颗粒形状之间的相互作用来全面了解内吞作用的机理复杂性,曲率,定位,膜张力,和粘合强度可以影响吞噬途径。
Understanding and manipulating the interactions between foreign bodies and cell membranes during endo- and phagocytosis is of paramount importance, not only for the fate of living cells but also for numerous biomedical applications. This study aims to elucidate the role of variables such as anisotropic particle shape, curvature, orientation, membrane tension, and adhesive strength in this essential process using a minimal experimental biomimetic system comprising giant unilamellar vesicles and rod-like particles with different curvatures and aspect ratios. We find that the particle wrapping process is dictated by the balance between the elastic free energy penalty and adhesion free energy gain, leading to two distinct engulfment pathways, tip-first and side-first, emphasizing the significance of the particle orientation in determining the pathway. Moreover, our experimental results are consistent with theoretical predictions in a state diagram, showcasing how to control the wrapping pathway from surfing to partial to complete wrapping by the interplay between membrane tension and adhesive strength. At moderate particle concentrations, we observed the formation of rod clusters, which exhibited cooperative and sequential wrapping. Our study contributes to a comprehensive understanding of the mechanistic intricacies of endocytosis by highlighting how the interplay between the anisotropic particle shape, curvature, orientation, membrane tension, and adhesive strength can influence the engulfment pathway.