diff --git "a/8dFLT4oBgHgl3EQftC_m/content/tmp_files/load_file.txt" "b/8dFLT4oBgHgl3EQftC_m/content/tmp_files/load_file.txt" new file mode 100644--- /dev/null +++ "b/8dFLT4oBgHgl3EQftC_m/content/tmp_files/load_file.txt" @@ -0,0 +1,619 @@ +filepath=/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf,len=618 +page_content='Wrapping pathways of anisotropic dumbbell particles by giant unilamellar vesicles Ali Azadbakht,†,∥ Billie Meadowcroft,‡,¶,∥ Thijs Varkevisser,†,§,∥ Anđela Šarić,‡ and Daniela J.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Kraft∗,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='† †Soft Matter Physics,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Huygens-Kamerlingh Onnes Laboratory,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Leiden University,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' PO Box 9504,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 2300 RA Leiden,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' the Netherlands ‡Institute of Science and Technology Austria,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 3400 Klosterneuburg,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Austria ¶Department of Physics and Astronomy,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Institute for the Physics of Living Systems,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' University College London,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' London WC1E 6BT,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' United Kingdom §Van der Waals-Zeeman Institute,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Institute of Physics,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' University of Amsterdam,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Science Park 904,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 1098 XH Amsterdam,' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Netherlands ∥These authors contributed equally to this work.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' E-mail: kraft@physics.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='leidenuniv.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='nl Abstract Endocytosis is a key cellular process involved in the uptake of nutrients, pathogens or the diagnosis and therapy of diseases.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Most studies have focused on spherical ob- jects, whereas biologically relevant shapes can be highly anisotropic.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' In this letter, we use an experimental model system based on Giant Unilamellar Vesicles (GUVs) and dumbbell-shaped colloidal particles to mimic and investigate the first stage of the pas- sive endocytic process: engulfment of an anisotropic object by the membrane.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Our model has specific ligand-receptor interactions realized by mobile receptors on the vesi- cles and immobile ligands on the particles.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Through a series of experiments, theory 1 arXiv:2301.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='12150v1 [cond-mat.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='soft] 28 Jan 2023 and molecular dynamics simulations, we quantify the wrapping process of anisotropic dumbbells by GUVs and identify distinct stages of the wrapping pathway.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We find that the strong curvature variation in the neck of the dumbbell as well as membrane tension are crucial in determining both the speed of wrapping and the final states.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' The engulfment of objects through the cell membrane is critical for endocytic processes such as phagocytosis1–3 and receptor-mediated endocytosis.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' The latter is often exploited by viruses for cell entry and proliferation4 and key to nanomedical applications such as drug delivery and imaging.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='5 To single out receptor-mediated effects from active mechanisms in- volved in the engulfment,6 simplified passive model systems can be employed, which recently led to a conclusive understanding of the wrapping of spherical objects.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='7,8 However, biological objects such as bacteria and viruses4,9,10 as well as nanoparticles relevant for applications in nanomedicine but also nanotoxicology11 often posses non-spherical shapes.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Moreover, in vitro experiments with nanoparticles and simulations have shown that the size and shape influence their likelihood to be taken up by endocytosis.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='6,12–17 The wrapping pathways of spheres at sufficiently low membrane tensions have been shown to be a continuous transition from attached to fully wrapped, occurring either spontaneously or after activation.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='7,8,18 In contrast, anisotropic particles such as ellipsoids and rods, are expected to reorient during the wrapping process or become trapped in metastable states due to their varying curvature.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='19–27 The aspect ratio of these particles as well as the degree of rounding of their tip were the key parameters affecting the wrapping orientation with respect to the membrane and their metastable and stable states.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='24,27 Despite the extensive work in theory and simulations and exciting observations on shape-dependence in phagocytosis,28 no experimental work has investigated the passive wrapping process of anisotropic particles by lipid membranes and tested these predictions yet.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' In this letter, we employ an experimental model system based on Giant Unilamellar Vesicles (GUVs) and colloidal dumbbell particles to investigate the wrapping of micrometre- sized anisotropic objects by lipid membranes.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Our model system is designed to have mobile 2 ligands on the vesicles and immobile receptors on the particles mimicking receptor-mediated endocytotic systems.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='18,29,30 We quantify the wrapping pathways of anisotropic dumbbells by lipid membranes and test if their initial orientation affects the final states.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Molecular dynamics simulations of the same system corroborate our experimental data, allowing us to inspect the dynamics of the process that was inaccessible to experiment.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We find that the strong curvature variation in the neck of the dumbbell as well as membrane tension and not their initial orientation are crucial in both determining the speed of wrapping and the final states.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We investigate the wrapping process of anisotropic objects by a lipid membrane using a model system consisting of GUVs and colloidal particles, (see Fig.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 1a).' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We chose the simplest object that features anisotropy: a dumbbell shaped colloidal particle that consists of two equal sized spheres.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' The colloid dumbbells were obtained from aggregating polystyrene spheres with diameter ds=0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='98± 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='03 µm31 by briefly lowering the pH to 5.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='3 and then quenching the process by increasing the pH to 8.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='6.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='32 This process yielded 5-10% dimers with a long axis of 1.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='96 ± 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='06 µm and a short axis of 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='98 ± 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='03 µm.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' GUVs were prepared by electroswelling from 97.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='5% w/w 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC).' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' To realize strong ligand-receptor mediated binding we doped the GUVs with 2% w/w 1,2- dioleoyl-sn-glycero-3-phosphoethanolamine-N-[biotin-2000] (DOPE-PEG2000-Biotin) and the dumbbells with 2.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='2×103/µm2 NeutrAvidin following,31 see Fig.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 1b and c and see particle functionalization and quantification of binding affinity in Supporting Information.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We sup- press electrostatic interactions by working in 50 mM Phosphate Buffered Saline, and achieve colloidal stability by coating the dumbbells with polyethyleneglycol (PEG5000).' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Imaging of the position and orientation of the dumbbells and membranes in three dimensions was made possible by dying the colloids with BODIPY, represented by a green color throughout the manuscript, as well as including 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='5% w/w 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine- N-(lissamine rhodamine B sulfonyl) (DOPE-Rhodamine) into the GUVs, represented by a magenta color.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' See Fig.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 1c.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Confocal stacks and image sequences were acquired with an 3 inverted Nikon TI-e microscope, equipped with a 60x (NA 1.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='2) objective and A1-R scan head.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' 2D image sequences were taken at 59 fps, which enables tracking of the dumbbells in real time.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' Experimental details are described in the Supporting Information.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' To initiate the wrapping process, we used optical tweezers to bring dumbbell particles in contact with the GUV.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' They subsequently diffused on the GUV surface before suddenly and quickly becoming wrapped, a process that took between a few seconds and a few minutes depending on membrane tension, see Figure 1e and Movie S1.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' To capture the wrapping pro- cess with high speed, we adjusted the focal height during acquisition of the image sequence.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' After wrapping, the dumbbell continued to diffuse on the inside of the vesicle.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We quantify the wrapping process of a dumbbell by measuring the angle θ between the major axis of the dumbbell and surface normal of the GUV and distance d of the dumbbell with respect to the undistorted surface of the GUV, see Figure 1d.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' We inferred the 3D position of the dumbbell from the position of its lobes with respect to the GUV.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content=' To improve the accuracy of tracking, particles were tracked only when their center of mass was between 0.' metadata={'source': '/home/zjlab/wf/langchain-ChatGLM/knowledge_base/8dFLT4oBgHgl3EQftC_m/content/2301.12150v1.pdf'} +page_content='8R