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1.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38474008

RESUMEN

Organic ammonium and phosphonium salts exert excellent antimicrobial effects by interacting lethally with bacterial membranes. Particularly, quaternary ammonium lipids have demonstrated efficiency both as gene vectors and antibacterial agents. Here, aiming at finding new antibacterial devices belonging to both classes, we prepared a water-soluble quaternary ammonium lipid (6) and a phosphonium salt (1) by designing a synthetic path where 1 would be an intermediate to achieve 6. All synthesized compounds were characterized by Fourier-transform infrared spectroscopy and Nuclear Magnetic Resonance. Additionally, potentiometric titrations of NH3+ groups 1 and 6 were performed to further confirm their structure by determining their experimental molecular weight. The antibacterial activities of 1 and 6 were assessed first against a selection of multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species, observing remarkable antibacterial activity of both compounds against Gram-positive isolates of Enterococcus and Staphylococcus genus. Further investigations on a wider variety of strains of these species confirmed the remarkable antibacterial effects of 1 and 6 (MICs = 4-16 and 4-64 µg/mL, respectively), while 24 h-time-killing experiments carried out with 1 on different S. aureus isolates evidenced a bacteriostatic behavior. Moreover, both compounds 1 and 6, at the lower MIC concentration, did not show significant cytotoxic effects when exposed to HepG2 human hepatic cell lines, paving the way for their potential clinical application.


Asunto(s)
Compuestos de Amonio , Humanos , Compuestos de Amonio/farmacología , Staphylococcus aureus , Compuestos de Amonio Cuaternario/química , Antibacterianos/farmacología , Bacterias Grampositivas , Bacterias , Cloruro de Sodio/farmacología , Cloruro de Sodio Dietético/farmacología , Lípidos/farmacología , Pruebas de Sensibilidad Microbiana
2.
Int J Nanomedicine ; 10: 2673-83, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25878500

RESUMEN

Nonviral gene and small interfering RNA (siRNA) delivery formulations are extensively used for biological and therapeutic research in cell culture experiments, but less so in in vivo and clinical research. Difficulties with formulating the nanoparticles for uniformity and stability at concentrations required for in vivo and clinical use are limiting their progression in these areas. Here, we report a simple but effective method of formulating monodisperse nanocomplexes from a ternary formulation of lipids, targeting peptides, and nucleic acids at a low starting concentration of 0.2 mg/mL of DNA, and we then increase their concentration up to 4.5 mg/mL by reverse dialysis against a concentrated polymer solution at room temperature. The nanocomplexes did not aggregate and they had maintained their biophysical properties, but, importantly, they also mediated DNA transfection and siRNA silencing in cultured cells. Moreover, concentrated anionic nanocomplexes administered by convection-enhanced delivery in the striatum showed efficient silencing of the ß-secretase gene BACE1. This method of preparing nanocomplexes could probably be used to concentrate other nonviral formulations and may enable more widespread use of nanoparticles in vivo.


Asunto(s)
ADN , Lípidos , Nanopartículas/química , Péptidos , ARN Interferente Pequeño , Transfección/métodos , Animales , Línea Celular Tumoral , ADN/química , ADN/aislamiento & purificación , Humanos , Lípidos/química , Lípidos/aislamiento & purificación , Ratones , Péptidos/química , Péptidos/aislamiento & purificación , ARN Interferente Pequeño/química , ARN Interferente Pequeño/aislamiento & purificación
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