Antibacterial and bactericidal activity of nitric oxide-releasing natural zeolite

Abstract

The zeolitic tuff from Gördes (Western Anatolia) was used as adsorbent for nitric oxide (NO) storage and release purposes. The NO loading of the zeolite was performed under 20 mL min − 1 NO flow at 30°C and then the zeolite was purged with inert gas in order to remove the species that were reversibly adsorbed and in the gas phase (desorption). The total and reversible adsorption capacities of the zeolite were determined from the adsorption and desorption breakthrough curves, respectively. The NO-loaded zeolite exhibited antibacterial and bactericidal activities against Gram-negative (Escherichia coli) and Gram-positive bacteria (Bacillus subtilis) under physiological conditions. From the NO release kinetics, the diffusion coefficient of NO in the zeolite particle was determined.

Cr(VI) sorption by using clinoptilolite and bacteria loaded clinoptilolite rich mineral

“…Water and exchangeable cations such as magnesium, sodium, calcium and potassium also exist in its structure. It has high potential for separation, purification, adsorption and ion exchange depending on the type of exchangeable cations and their specific positions within the framework structure [4][5][6][7][8][9][10][11][12]. Additionally, high selective cation exchange capacity makes clinoptilolite rich mineral useful in waste water treatment especially in the removal of ammonium and heavy metals such as copper, cadmium, iron, lead, nickel, silver and zinc [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Adsorption of NO in clinoptilolite-rich zeolitic mineral by concentration pulse chromatography method

“…Preparation and characterization of the zeolitic material (NZ) have been reported in our previous study [66]. Briefly, NZ contains predominantly clinoptilolite (67 wt %) as well as quartz, feldspars and biotite as mineral impurities.…”

“…The micropore volume was determined from CO 2 adsorption isotherms (obtained at 30 C using a volumetric adsorption equipment ASAP 2000, Micromeritics) by the application of the Dubinin-Astakhov model. The average adsorbent crystal radius was determined from the scanning electron micrographs given in our previous study [66].…”

“…The NO storage and release properties of this material have been previously examined by our group. In that study total, reversible and irreversible NO adsorption capacities of the material have been determined and it was shown that NZ can store and release NO thereby exhibits antibacterial/ bactericidal activity [66].…”

Kinetic and equilibrium studies of adsorption of β-glucuronidase by clinoptilolite-rich minerals

“…Recently the incorporation of organic molecules onto clinoptilolite and synthetic zeolites has attracted growing interest because their frameworks are suitable for the encapsulation and/or adsorption of different molecules. They are used for protein adsorption, separation or enzyme immobilization and have been suggested as drug support systems, antibacterial agent release matrices or bacteria loading supports [3][4][5][6][7][8][9]. Clinoptilolite and its modified forms were used to protect animals from feed-originating toxins by adsorbing toxic compounds in the gastrointestinal tract and preventing their passage into the circulatory system [10][11][12][13][14].…”