In Vitro Antimicrobial Studies of Mesoporous Silica Nanoparticles Comprising Anionic Ciprofloxacin Ionic Liquids and Organic Salts.
Luís FilipeTelma de SousaDário SilvaMiguel M SantosManuela Ribeiro CarrottPatrícia PoetaLuís Cobra BrancoSandra GagoPublished in: Pharmaceutics (2023)
The combination of active pharmaceutical ingredients in the form of ionic liquids or organic salts (API-OSILs) with mesoporous silica nanoparticles (MSNs) as drug carriers can provide a useful tool in enhancing the capabilities of current antibiotics, especially against resistant strains of bacteria. In this publication, the preparation of a set of three nanomaterials based on the modification of a MSN surface with cholinium ([MSN-Chol][Cip]), 1-methylimidazolium ([MSN-1-MiM][Cip]) and 3-picolinium ([MSN-3-Pic][Cip]) ionic liquids coupled with anionic ciprofloxacin have been reported. All ionic liquids and functionalized nanomaterials were prepared through sustainable protocols, using microwave-assisted heating as an alternative to conventional methods. All materials were characterized through FTIR, solution 1 H NMR, elemental analysis, XRD and N 2 adsorption at 77 K. The prepared materials showed no in vitro cytotoxicity in fibroblasts viability assays. The minimum inhibitory concentration (MIC) for all materials was tested against Gram-negative K. pneumoniae and Gram-positive Enterococcus spp., both with resistant and sensitive strains. All sets of nanomaterials containing the anionic antibiotic outperformed free ciprofloxacin against resistant and sensitive forms of K. pneumoniae , with the prominent case of [MSN-Chol][Cip] suggesting a tenfold decrease in the MIC against sensitive strains. Against resistant K. pneumoniae , a five-fold decrease in the MIC was observed for all sets of nanomaterials compared with neutral ciprofloxacin. Against Enterococcus spp., only [MSN-1-MiM][Cip] was able to demonstrate a slight improvement over the free antibiotic.