فهرست مطالب h. yaghoubi

In recent years, carbon nanotubes have attracted the attention of many researchers because of their unique properties. In the present study, carbon nanotubes were coated using PEI. Then, their ability to gene delivery to E. coli cells was examined.

Nanotube- PEI nanoparticles were synthesized by the reaction between amine groups of PEI and carboxyl groups of nanotubes. In order to prepare the appropriate DNA vector for delivering to E. coli cells, the Gus A gene was transferred from pBI121 to PUC18 vector (pUC-Gus). Nanotube-PEI/DNA complexes were prepared by combining different mass ratios of nanotube-PEI (0.5, 1, and 2 w/w%) with the fixed amount of DNA. To the transformation of E. coli, the appropriate amount of nanotube-PEI/DNA complexes was added to E. coli cells under stirring at 37°C for 7h. The transformation efficiency of E. coli was determined by colony counting on LB agar supplemented with Ampicillin. Moreover, Gus staining assay was used to confirm the function of the plasmid. Determination of cytotoxicity of nanotube-PEI was performed using MTT assay at 6, 24, and 72 hours intervals at different concentrations of nanotube-PEI (10, 100, and 500μg/ml).

The nanotube-PEI was synthesized successfully. Nanotube- PEI nanoparticles have a great ability to protect DNA from enzymatic digestion. The percentage of E. coli cells viability was decreased by increasing both the concentration of nanotube-PEI nanoparticles and also the duration of incubation. The results of the agarose gel electrophoresis of plasmid extracted from E. coli and digested using EcoRI enzyme showed that the pUC-Gus plasmid has been successfully transfected by nanotube-PEI nanoparticles to E. coli bacterial cells.

Cationic carbon nanotubes have a high ability to gene transfer to E. coli.

Silver nanoparticles have antibacterial and anticancer activity. But the organic solvents used to produce these nanoparticles are toxic and can have devastating environmental effects. Therefore, there is a strong desire to use healthy methods for the synthesis of silver nanoparticles. Therefore, this study was performed to synthesize silver nanoparticles biologically from aqueous extract of Truffle and to study their biological effects on cancer cells.

In this experimental study, to synthesize silver nanoparticles from aqueous extract of Truffle, 10 ml of fungus extract was added to 90 ml of 1 ml silver nitrate solution and incubated for 72 hours at room temperature. The physicochemical properties of the nanoparticles synthesized by XRD, FESEM and TEM were analyzed. Effects of Extract and Synthesized Nanoparticles were studied by MTT at concentrations of 0.025, 0.25, 0.25, 0.5 and 1 mg / ml on MCF-7 Cancer Cells at 72, 48, and 24 hours.

The size of the nanoparticles was between 19 and 35 nm and their shape was mainly spherical. In cytotoxicity assay using MTT assay IC50 calculated for silver nanoparticles and extract in MCF-7 cells showed that silver nanoparticles had more cytotoxic effects than extract. The calculated IC50 for extracts and nanoparticles at 24, 48 and 72 hours were 0.73, 0.8, and 0.64 mg / ml, respectively, and for the nanoparticles were 0.6, 0.5, and 0.48, respectively (p <0.05).

The silver nanoparticles produced by bio-synthesis method have a higher cytotoxicity than the truffle fungus (Tuber spp.) extract.