| dc.description.abstract |
Membrane potential plays a significant role in various cellular processes while interacting with membrane active agents. This study predominantly investigates at how anionic magnetite nanoparticles (NPs) generate pores and change the shapes of giant unilamellar vesicles (GUVs), which are mimic of cells. Importantly, this investigation is conducted under different membrane potentials to more closely mimic real cellular conditions. Lipids 1,2-dioleoyl-sn-glycero-3-phospho-(1´-rac-glycerol) (DOPG), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and channel forming protein gramicidin A (GrA) are used to synthesize the DOPG/DOPC/GrA-GUVs. The static and dynamic characteristics of GUVs examined using phase contrast fluorescent microscopy. The addition of GrA into the vesicle's membrane leads to a reduction in the rate of leakage of an encapsulated fluorescent probe (calcein), particularly when there is no membrane potential applied. However, as the membrane potential becomes negative, the leakage behavior shifts from a single exponential pattern to a two-exponential pattern, resulting in the existence of two distinct leakage rates. This means that leakage occurs more rapidly in the initial phase, but the rate slows down during the final phase as the negative membrane potential increases. Moreover, as the negative membrane potential rises, both the fraction of poration and the degree of deformation also increase. These findings indicate that the membrane potential intensifies the poration caused by NPs and contributes to the deformation of DOPG/DOPC/GrA-GUVs. The increase of the binding constant between NPs and the membrane plays a crucial role to enhance membrane permeation and vesicle deformation. |
en_US |