Ahmed Nazia, Nasrin Tawfika, Sayem Karal Mohammad Abu
Department of Physics, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh.
Department of Mathematical and Physical Sciences, East West University, Dhaka, Bangladesh.
PLoS One. 2025 Jul 7;20(7):e0327639. doi: 10.1371/journal.pone.0327639. eCollection 2025.
Magnetite nanoparticles (MNPs, Fe3O4) have gained substantial interest for different biomedical and biochemical applications. Therefore, it is important to understand the mechanism of interaction between MNPs and cell membranes. As a model for cells, giant unilamellar vesicles (GUVs) are used in various research studies, providing valuable insights into the behavior of lipid bilayers and their interactions with MNPs. To understand the mechanism of interaction between MNPs and membranes, the dynamics of a 'single GUV' are explored using the micropipette technique under physiological conditions. The GUVs exhibited deformation upon adsorption of anionic MNPs into the membrane, with the degree of deformation (e.g., compactness) increasing over time. The addition of MNPs through a micropipette into the vicinity of a 'single GUV' induced various shape changes; for example, a prolate shape transformed into two spheres connected by a neck. The fraction of the shape changes of GUVs increased with the concentration of MNPs. These results indicated that MNPs were absorbed onto the outer monolayer, inducing an area mismatch between the outer and inner monolayers of the membrane. The change in membrane area upon MNP binding in a 'single GUV' was investigated using the micropipette aspiration technique. Initially, the membrane area increased at a faster rate until reaching a saturation point, then decreased at a slower rate back to the original point, followed by a slight increase at a very slow rate. These changes suggest rapid stretching, slower compression, and finally slow stretching in the membranes of the GUV. Based on these results, we discuss the interaction mechanism of anionic MNPs with a single GUV.
磁铁矿纳米颗粒（MNPs，Fe3O4）在不同的生物医学和生物化学应用中引起了广泛关注。因此，了解MNPs与细胞膜之间的相互作用机制非常重要。作为细胞模型，巨型单层囊泡（GUVs）被用于各种研究中，为脂质双层的行为及其与MNPs的相互作用提供了有价值的见解。为了理解MNPs与膜之间的相互作用机制，在生理条件下使用微量移液器技术探索了“单个GUV”的动力学。当阴离子MNPs吸附到膜中时，GUVs表现出变形，变形程度（例如紧密度）随时间增加。通过微量移液器将MNPs添加到“单个GUV”附近会引起各种形状变化；例如，长圆形会转变为通过颈部连接的两个球体。GUVs形状变化的比例随MNPs浓度的增加而增加。这些结果表明MNPs被吸附到外层单分子层上，导致膜的外层和内层单分子层之间出现面积不匹配。使用微量移液器抽吸技术研究了“单个GUV”中MNP结合后膜面积的变化。最初，膜面积以较快的速率增加，直到达到饱和点，然后以较慢的速率减小回到原始点，随后以非常缓慢的速率略有增加。这些变化表明GUV膜中存在快速拉伸、较慢压缩以及最终的缓慢拉伸。基于这些结果，我们讨论了阴离子MNPs与单个GUV的相互作用机制。
