Synthesis of a novel ternary ZIF-8/GO/MgFe2O4 nanocomposite and its application in drug delivery.

In recent year, metal-organic frameworks (MOFs) have been displayed to be a category of promising drug delivery systems because of their crystalline structure, the potential of further functionality, and high porosity. In this research, graphene oxide was synthesized from pure graphite via hummer method and then MgFe2O4 nanoparticles was incorporated into the synthesized ZIF-8 metal-organic frameworks which followed with loading on the surfaces of graphene oxide. In continue, tetracycline as an antibiotic drug was loaded on the surfaces and the cavities of the prepared nanocomposite. The outcomes of this research revealed that 90% of the tetracycline was loaded on the synthesized ZIF-8/GO/MgFe2O4 nanostructure. Next, drug release was done at pH: 5 and pH: 7.4 within 3 days, resulting about 88% and 92% release of the tetracycline, respectively. With using different spectroscopic methods like X-ray crystallography (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX/Mapping), Fourier transform infrared (FTIR), thermalgravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET), the structure of synthesized materials was confirmed. Furthermore, the antibiotic activity of tetracycline trapped into the ZIF-8/GO/MgFe2O4 was evaluated by agar-well diffusion method on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, which showed good antibacterial results.

Application of RSM for optimization of glutamic acid production by Corynebacterium glutamicum in bath culture.

Glutamate plays an important role in different cellular processes. Its new applications in various industries have led to an increase in the production of it while fermentation is a very important economically method. In this study, the production of glutamate by the wild type of Corynebacterium glutamicum PTCC(Persian Type Culture Collection) 1532 was optimized using RSM. Central Composite Design (CCD) was developed by Design-Expert software version 12.0.3.0 (dx-12, State-Ease Inc.) to evaluate the effect of four important variables in five levels on glutamate production. TLC was employed to evaluate glutamate in medium qualitatively and then quantitative estimation was done by HPLC. Normal probability analysis demonstrated that data has a normal distribution. The results of ANOVA analysis showed that the urea concentration both alone and with temperature is the most effective variable in the fermentation process. Based on the quadratic model obtained in CCD, temperature 30 °C; glucose 9 g.dL-1; biotin 9 µg.L-1 and urea concentration of 0.3 g.dL-1 were found optimum conditions with a predicted glutamate production of 19.84 mg.mL-1 with desirable level 1. Therefore RSM can be an effective method to optimize glutamate production and the findings of this study are a guideline for the other amino acids fermentation by C. glutamicum.

Synthesis, identification and application of the novel metal-organic framework Fe3O4@PAA@ZIF-8 for the drug delivery of ciprofloxacin and investigation of antibacterial activity.

Today, metal-organic frameworks (MOFs) for the release of drugs have been studied extensively. In this research, we have investigated the novel magnetic framework including Fe3O4@PAA@ZIF-8 for the delivery of ciprofloxacin (CIP) antibiotic. Moreover, the antibacterial activity of Fe3O4@PAA@ZIF-8 and Fe3O4@PAA@ZIF-8@CIP screened against Staphylococcus aureus ( S. aureus) and Escherichia coli ( E. coli) bacteria. The structure of the nano carrier, as well as the encapsulation of the drug in the framework was confirmed by the Fourier-transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Energy-dispersive X-ray spectroscopy (EDX), X-ray crystallography (XRD), Scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) analysis. The results of this study showed that 93% of the CIP was loaded on the synthesized framework. Drug release was done at pH: 7.4 and pH: 5 within 2 d, resulting about 73% release of the drug.