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Canepa E, Bochicchio D, Brosio G, Silva PHJ, Stellacci F, Dante S, Rossi G, Relini A. Cholesterol-Containing Liposomes Decorated With Au Nanoparticles as Minimal Tunable Fusion Machinery. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207125. [PMID: 36899445 DOI: 10.1002/smll.202207125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/30/2023] [Indexed: 06/08/2023]
Abstract
Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological conditions, fusion events are regulated by a wide range of specialized proteins, operating with finely tuned local lipid composition and ionic environment. Fusogenic proteins, assisted by membrane cholesterol and calcium ions, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release. Similar cooperative effects must be explored when considering synthetic approaches for controlled membrane fusion. We show that liposomes decorated with amphiphilic Au nanoparticles (AuLips) can act as minimal tunable fusion machinery. AuLips fusion is triggered by divalent ions, while the number of fusion events dramatically changes with, and can be finely tuned by, the liposome cholesterol content. We combine quartz-crystal-microbalance with dissipation monitoring (QCM-D), fluorescence assays, and small-angle X-ray scattering (SAXS) with molecular dynamics (MD) at coarse-grained (CG) resolution, revealing new mechanistic details on the fusogenic activity of amphiphilic Au nanoparticles (AuNPs) and demonstrating the ability of these synthetic nanomaterials to induce fusion regardless of the divalent ion used (Ca2+ or Mg2+ ). The results provide a novel contribution to developing new artificial fusogenic agents for next-generation biomedical applications that require tight control of the rate of fusion events (e.g., targeted drug delivery).
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Affiliation(s)
- Ester Canepa
- Department of Physics, University of Genoa, Genoa, 16146, Italy
- Institute of Materials Science & Engineering, EPFL, Lausanne, 1015, Switzerland
| | | | - Giorgia Brosio
- Department of Physics, University of Genoa, Genoa, 16146, Italy
| | | | - Francesco Stellacci
- Materials Characterization Facility, Istituto Italiano di Tecnologia, Genoa, 16163, Italy
| | - Silvia Dante
- Institute of Materials Science & Engineering, EPFL, Lausanne, 1015, Switzerland
| | - Giulia Rossi
- Department of Physics, University of Genoa, Genoa, 16146, Italy
| | - Annalisa Relini
- Department of Physics, University of Genoa, Genoa, 16146, Italy
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Kariuki R, Penman R, Bryant SJ, Orrell-Trigg R, Meftahi N, Crawford RJ, McConville CF, Bryant G, Voïtchovsky K, Conn CE, Christofferson AJ, Elbourne A. Behavior of Citrate-Capped Ultrasmall Gold Nanoparticles on a Supported Lipid Bilayer Interface at Atomic Resolution. ACS NANO 2022; 16:17179-17196. [PMID: 36121776 DOI: 10.1021/acsnano.2c07751] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanomaterials have the potential to transform biological and biomedical research, with applications ranging from drug delivery and diagnostics to targeted interference of specific biological processes. Most existing research is aimed at developing nanomaterials for specific tasks such as enhanced biocellular internalization. However, fundamental aspects of the interactions between nanomaterials and biological systems, in particular, membranes, remain poorly understood. In this study, we provide detailed insights into the molecular mechanisms governing the interaction and evolution of one of the most common synthetic nanomaterials in contact with model phospholipid membranes. Using a combination of atomic force microscopy (AFM) and molecular dynamics (MD) simulations, we elucidate the precise mechanisms by which citrate-capped 5 nm gold nanoparticles (AuNPs) interact with supported lipid bilayers (SLBs) of pure fluid (DOPC) and pure gel-phase (DPPC) phospholipids. On fluid-phase DOPC membranes, the AuNPs adsorb and are progressively internalized as the citrate capping of the NPs is displaced by the surrounding lipids. AuNPs also interact with gel-phase DPPC membranes where they partially embed into the outer leaflet, locally disturbing the lipid organization. In both systems, the AuNPs cause holistic perturbations throughout the bilayers. AFM shows that the lateral diffusion of the particles is several orders of magnitude smaller than that of the lipid molecules, which creates some temporary scarring of the membrane surface. Our results reveal how functionalized AuNPs interact with differing biological membranes with mechanisms that could also have implications for cooperative membrane effects with other molecules.
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Affiliation(s)
- Rashad Kariuki
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Rowan Penman
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Saffron J Bryant
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Rebecca Orrell-Trigg
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Nastaran Meftahi
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - Russell J Crawford
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Chris F McConville
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
- Deakin University, Geelong, VIC 3220, Australia
| | - Gary Bryant
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Kislon Voïtchovsky
- University of Durham, Physics Department, Durham DH1 3LE, United Kingdom
| | - Charlotte E Conn
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Andrew J Christofferson
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - Aaron Elbourne
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
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