The potential toxicity of ligand-protected nanoparticles (NPs) on biological targets is crucial f... more The potential toxicity of ligand-protected nanoparticles (NPs) on biological targets is crucial for their clinical translation. A number of studies are aimed at investigating the molecular mechanisms shaping the interactions between synthetic NPs and neutral plasma membranes. The role played by the NP surface charge is still widely debated. We compare, via liposome leakage assays, the perturbation induced by the penetration of sub-6 nm anionic and cationic Au NPs into model neutral lipid membranes composed of the zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Our charged Au NPs are functionalized by a mixture of the apolar 1-octanethiol and a ω-charged thiol which is either the anionic 11-mercapto-1-undecanesulfonate or the cationic (11-mercaptoundecyl)-N,N,N-trimethylammonium. In both cases, the NP uptake in the bilayer is confirmed by quartz crystal microbalance investigations. Our leakage assays show that both negatively and positively charged Au NPs do not...
Atomic force microscopy (AFM) is a nano‐mechanical tool uniquely suited for biological studies at... more Atomic force microscopy (AFM) is a nano‐mechanical tool uniquely suited for biological studies at the molecular scale. AFM operation is based on mechanical interaction between the tip and the sample, a mechanism of contrast capable of measuring different information, including surface topography, mechanical, and electrical properties. However, the lack of specificity highlights the need to integrate AFM data with other techniques providing compositional hints. In particular, optical microscopes based on fluorescence as a mechanism of contrast can access the local distribution of specific molecular species. The coupling between AFM and super‐resolved fluorescence microscopy solves the resolution mismatch between AFM and conventional fluorescence optical microscopy. Recent advances showed that also the inherently label‐free imaging capabilities of the AFM are fundamental to complement the fluorescence images. In this review, we have presented a brief historical view on correlative mic...
Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological co... more 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, as well as by a finely tuned local lipid composition and ionic environment. SNARE proteins, for example, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release, and their action is assisted by other soluble proteins, membrane cholesterol, and calcium ions. Similar cooperative effects must be explored when considering synthetic approaches to achieve controlled and selective membrane fusion. Here 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 depends on, and can be finely tuned by, the liposome cholesterol content. Our results, obtained via a combination of experimental (Quartz-Crystal-Microbalance with Dissipatio...
The potential toxicity of ligand-protected nanoparticles (NPs) on biological targets is crucial f... more The potential toxicity of ligand-protected nanoparticles (NPs) on biological targets is crucial for their clinical translation. A number of studies are aimed at investigating the molecular mechanisms shaping the interactions between synthetic NPs and neutral plasma membranes. The role played by the NP surface charge is still widely debated. We compare, via liposome leakage assays, the perturbation induced by the penetration of sub-6 nm anionic and cationic Au NPs into model neutral lipid membranes composed of the zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Our charged Au NPs are functionalized by a mixture of the apolar 1-octanethiol and a ω-charged thiol which is either the anionic 11-mercapto-1-undecanesulfonate or the cationic (11-mercaptoundecyl)-N,N,N-trimethylammonium. In both cases, the NP uptake in the bilayer is confirmed by quartz crystal microbalance investigations. Our leakage assays show that both negatively and positively charged Au NPs do not...
Atomic force microscopy (AFM) is a nano‐mechanical tool uniquely suited for biological studies at... more Atomic force microscopy (AFM) is a nano‐mechanical tool uniquely suited for biological studies at the molecular scale. AFM operation is based on mechanical interaction between the tip and the sample, a mechanism of contrast capable of measuring different information, including surface topography, mechanical, and electrical properties. However, the lack of specificity highlights the need to integrate AFM data with other techniques providing compositional hints. In particular, optical microscopes based on fluorescence as a mechanism of contrast can access the local distribution of specific molecular species. The coupling between AFM and super‐resolved fluorescence microscopy solves the resolution mismatch between AFM and conventional fluorescence optical microscopy. Recent advances showed that also the inherently label‐free imaging capabilities of the AFM are fundamental to complement the fluorescence images. In this review, we have presented a brief historical view on correlative mic...
Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological co... more 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, as well as by a finely tuned local lipid composition and ionic environment. SNARE proteins, for example, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release, and their action is assisted by other soluble proteins, membrane cholesterol, and calcium ions. Similar cooperative effects must be explored when considering synthetic approaches to achieve controlled and selective membrane fusion. Here 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 depends on, and can be finely tuned by, the liposome cholesterol content. Our results, obtained via a combination of experimental (Quartz-Crystal-Microbalance with Dissipatio...
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Papers by silvia dante