Silver ciprofloxacin (CIPAG): a successful combination of chemically modified antibiotic in inorganic-organic hybrid.

The new silver(I) ionic, water soluble, compound {[Ag(CIPH)2]NO3∙0.75MeOH∙1.2H2O} (CIPAG) was obtained by reacting silver(I) nitrate with the antibiotic ciprofloxacin (CIPH). The complex was characterized by m.p., mid-FT-IR, 1H-NMR, UV-Vis spectroscopic techniques. The crystal structures of both CIPAG and the hexahydrated neutral free drug {[CIPH]∙6(H2O)} (2) were characterized by X-ray crystallography. Two neutral ligands are datively bonded to the metal ion through the piperidinic nitrogen atoms forming a cationic {[Ag(CIPH)2]+} counter part which is neutralized by a nitrate group. The antibacterial effect of CIPAG and the commercially available hydrochloric salt of the antibiotic ({[CIPH 2+ ]∙Cl - } (3)) were tested against the bacterial species Pseudomonas aeruginosa (PAO1), Staphylococcus epidermidis (St. epidermidis) and Staphylococcus aureus (St. aureus) by the mean of minimum inhibitory concentration, minimum bactericidal concentration and their inhibitory zone (IZ). The influence of CIPAG and 3 against the formation of biofilm of PAO1 or St. aureus was also evaluated by mean of biofilm elimination concentration. The IZ caused by CIPAG which has been loaded in poly-hydroxyethylmethacrylate, is determined. The genotoxicity of CIPAG and 3 is tested in vitro against normal human corneal epithelial cells (HCET cells), by the presence of micronucleus in HCET cells and in vivo by mean of Allium cepa test.

pHEMA@AGMNA-1: A novel material for the development of antibacterial contact lens.

The Metal Organic Framework (MOF) of formula {[Ag6(µ3-HMNA)4(µ3-MNA)2]2-·[(Et3NH)+]2·(DMSO)2·(H2O)} (AGMNA), a known efficient antimicrobial compound which contains the anti-metabolite, 2-thio-nicotinic acid (H2MNA), was incorporated in polymer hydrogels using, hydroxyethyl-methacrylate (HEMA). The material pHEMA@AGMNA-1 was characterized by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Thermogravimetric Differential Thermal Analysis (TG-DTA), Differential Scanning Calorimetry (DTG/DSC), attenuated total reflection spectroscopy (FT-IR-ATR) and Ultrasonic Imaging. The antimicrobial capacity of pHEMA@AGMNA-1 was evaluated against the Gram negative bacterial strain Pseudomonas aeruginosa and the Gram positive ones of the genus of Staphylococcus epidermidis and Staphylococcus aureus, which are the etiology of the microbial keratitis. The % bacterial viability of P. aeruginosa, S. epidermidis and S. aureus upon their incubation with pHEMA@AGMNA-1 discs is significantly low (0.4 ± 0.1%, 1.5 ± 0.4% and 7.7 ± 0.5% respectively). The inhibition zones (IZ) caused by pHEMA@AGMNA-1 discs against P. aeruginosa, S. epidermidis and S. aureus are 14.0 ± 1.1, 11.3 ± 1.3 and 11.8 ± 1.8 mm respectively. Furthermore, pHEMA@AGMNA-1 exhibits low toxicity. Thus, pHEMA@AGMNA-1 might be an efficient candidate for the development of antimicrobial active contact lenses.