123349-44-0Relevant academic research and scientific papers
Influence of the Spatial Distribution of Cationic Functional Groups at Nanoparticle Surfaces on Bacterial Viability and Membrane Interactions
Cahill, Meghan S.,Davis, Larissa S.,Feng, Z. Vivian,Frand, Seth D.,Hamers, Robert J.,Haynes, Christy L.,Hudson-Smith, Natalie V.,Zhang, Yongqian
, p. 10814 - 10823 (2020)
While positively charged nanomaterials induce cytotoxicity in many organisms, much less is known about how the spatial distribution and presentation of molecular surface charge impact nanoparticle-biological interactions. We systematically functionalized diamond nanoparticle surfaces with five different cationic surface molecules having different molecular structures and conformations, including four small ligands and one polymer, and we then probed the molecular-level interaction between these nanoparticles and bacterial cells. Shewanella oneidensis MR-1 was used as a model bacterial cell system to investigate how the molecular length and conformation of cationic surface charges influence their interactions with the Gram-negative bacterial membranes. Nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) demonstrate the covalent modification of the nanoparticle surface with the desired cationic organic monolayers. Surprisingly, bacterial growth-based viability (GBV) and membrane damage assays both show only minimal biological impact by the NPs functionalized with short cationic ligands within the concentration range tested, yet NPs covalently linked to a cationic polymer induce strong cytotoxicity, including reduced cellular viability and significant membrane damage at the same concentration of cationic groups. Transmission electron microscopy (TEM) images of these NP-exposed bacterial cells show that NPs functionalized with cationic polymers induce significant membrane distortion and the production of outer membrane vesicle-like features, while NPs bearing short cationic ligands only exhibit weak membrane association. Our results demonstrate that the spatial distribution of molecular charge plays a key role in controlling the interaction of cationic nanoparticles with bacterial cell membranes and the subsequent biological impact. Nanoparticles functionalized with ligands having different lengths and conformations can have large differences in interactions even while having nearly identical zeta potentials. While the zeta potential is a convenient and commonly used measure of nanoparticle charge, it does not capture essential differences in molecular-level nanoparticle properties that control their biological impact.
Hybrid nanoreceptors for high sensitivity detection of small molecules by NMR chemosensing
De Biasi, Federico,Rosa-Gastaldo, Daniele,Mancin, Fabrizio,Rastrelli, Federico
supporting information, p. 3002 - 3005 (2021/03/29)
“Nanoparticle-assisted NMR chemosensing” combines magnetization transfer NMR techniques with the recognition abilities of gold nanoparticles (AuNPs) to isolate the NMR spectrum of relevant organic species in mixtures. The efficiency of the magnetization transfer is crucial to set the detection limit of the technique. To this aim, a second generation of nanoreceptors obtained by the self-organization of 2 nm AuNPs onto the surface of bigger silica nanoparticles shows better magnetization transfer performances, allowing the detection of analytes in water down to 10 μM concentration using standard instrumentation.
Preparation and antimicrobial behaviour of quaternary ammonium thiol derivatives able to be grafted on metal surfaces
Thebault, Pascal,Taffin de Givenchy, Elisabeth,Levy, Richard,Vandenberghe, Yves,Guittard, Frederic,Geribaldi, Serge
experimental part, p. 717 - 724 (2009/09/05)
New thiol derivatives containing a quaternary ammonium group bearing variable hydrocarbon chains via an amide connector or not between the sulphur and nitrogen atoms were synthesised with the future aim to be grafted on metal surfaces for obtaining contact-active auto-bactericidal surfaces. Their biostatic and bactericidal activities were evaluated against four microbial strains (Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus niger and Candida albicans). The presence of the thiol and amide functions in these surfactants was discussed in relation with the antimicrobial activity along with the influence of the length of alkyl chains in order to determine which molecular parameters are 'critical' for biological activity, and consequently what molecules must be chosen for grafting on metal surface.
