Introduction: In recent years, the use of natural compounds to fight cancer has received attention due to the few side effects and promising effects.
Recently, many natural treatment methods against cancer have proven that magnetic bacteria can be successful in magnetosome-based methods.
The treatment of cancerous tumors is very difficult because the metabolism and oxygen levels of the cells in the outer and inner parts of the tumor are completely different, and this makes the treatment difficult.
Researchers at McGill University and Polytechnic University in Canada used magnetic bacteria to solve this problem. These bacteria are easily guided by a weakened magnetic field and reach the tumor site and deliver medicine.
Another advantage of these bacteria is that they tend to migrate to places without oxygen, and the core of the tumor is exactly where the concentration of oxygen is low.
Also, the magnetic field required for the movement of bacterial nano-robots is very weak and does not harm the body.
Researchers at McGill University and Polytechnic University in Canada used magnetic bacteria to solve this problem. These bacteria are easily guided by a weakened magnetic field and reach the tumor site and deliver medicine.
Another advantage of these bacteria is that they tend to migrate to places without oxygen, and the core of the tumor is exactly where the concentration of oxygen is low.
Also, the magnetic field required for the movement of bacterial nano-robots is very weak and does not harm the body.
Methods: The standard strain of Magnetospirillium Griffis Waldens type MSR-1 with special code (DSM6361) was purchased from Detschesammlung von microorganismen und zellkulturen, Germany. This strain was grown in the special culture medium of DSMZ, Germany. To prepare the material culture medium, according to the standard method, DSMZ Medium 380 (Germany) of Magnetospirillum bacteria was used. A solution of mineral elements and a solution of vitamins in a volume of one liter and a solution of ferric quinate in a volume of 100 milliliters were prepared. For each liter of mother solution, 10 milliliters of vitamin solution, 5 millimolar solution of mineral elements, 2 millimolar solution of ferric quinate, 0.68 grams of KH2PO4, 0.37 grams of succinic acid, L(+)-Tartaric
Na-thioglycolate, 0.05 gram Na, 0.37 gram acid
Resazurin gram and 0.12 NaNO3 acetate, 0.05 gram
0.5 mg was used. Before mixing these compounds, the pH of the solution containing mineral elements was raised to 6.5 by adding KOH or potassium hydroxide and deoxygenated with the help of N2 gas. Ferric quinate solution and mineral elements were autoclaved for 15 minutes with a pressure of 15 pas at a temperature of 121 degrees Celsius.
After autoclaving, when the temperature of the solution reached 45 degrees Celsius, the filtered vitamin solution was added to it. The vitamin solution contains Pyridoxine-Thiamine-, Riboflavin, Nicotinic acid, HClHCl·2H2O, Folic acid. Other materials were obtained from Merck, Germany. With a sterile needle, some of the MSR-1 bacteria inside the medium was removed and injected into the bacterial culture medium, and then placed in an anaerobic jar and connected to the anoxomat device for charging, and for 1 week to 10 days for the growth of the bacteria in the incubator. After 1 week to 01 days when the bacteria grew on the liquid medium, it was removed from the liquid medium and cultured on DSMZ solid culture medium in a linear culture and in an anaerobic and aerobic jar at 82 Celsius degree was kept for 1 week to 01 days. In order to identify the bacteria from the warm staining and evaluate the movement of the bacteria under the microscope, it was done using a magnetic magnet. For this purpose, some of the grown bacteria was removed with a syringe and placed on a glass slide, and distilled water was poured on it, and the movement of the bacteria was observed and recorded under a light microscope by placing a magnet from the north and south poles.
In order to closely examine the bacteria and observe the iron nanoparticles inside, photography was done with a Zeiss EM900 electron microscope. To observe the sample using an electron microscope, a few drops of the thickened culture medium containing bacteria were removed and poured onto the grid (copper grid). After drying, the WFI (injection water) was placed in a special chamber and was observed and photographed by an electron microscope (Ziemens 300kv) in the laboratory of Khaja Nasir Tusi Air and Space College (41). To separate and
The purification of magnetosomes was done using a physical method, where the bacterial wall was broken using a French press (Thermo company, Germany) and the cell extract was obtained. This device causes cell lysis by direct pressure. The way it works is that by centrifuging the culture medium at 7000 revolutions per minute, it separates the bacteria from the medium. At the end, the sediment obtained is removed from the outlet of the device. About 100 grams (based on bacterial OD calculations) of Magnetospirillium griffis waldens cells extracted in 50 ml of 50 mM HEPES and 4 mM EDTA by passing three times through the French press (2000IB/IN2) to break the bacterial cell wall. Kurd (all the mentioned buffers that were used for magnetosome extraction contain phenylmethylsulfonyl fluoride as a protein inhibitor).
Healthy cells and cell debris were separated by a centrifuge at 10,000 rpm. The supernatant liquid was passed through the magnetic separation column (the column was placed between two magnets, which produces a strong magnetic field and is a magnetic iron absorber). First, the magnetic particles were extracted with 50 ml of 10 mM HEPES and 200 mM NaCl.
(pH=4.7) then it was washed with 100 ml of 10 mM HEPES. Then the column was cleaned of magnetic particles and the magnetic particles were removed from the column with 10 mM HEPES buffer by flushing or by pressure and kept in the refrigerator.
For molecular identification, DNA extraction was performed using a kit (Azma-Iran) according to the instructions of the kit.
For more precise identification and for amplification, specific primers MT12166 of magnetospirillium griffis were used. Polymerase chain reaction was performed using a thermocycler (Bio Rad-USA). All reaction components were purchased from Yekta Azam Equipment Company.
The reaction mixture includes: 52 microliters of Master Mix (includes PCR buffer with a concentration of 100 times, magnesium chloride, dNTP, Taq DNA polymerase enzyme), 3 microliters of DNA, 2 microliters of primers (5)
Results: After preparing the BM-PEI-siRNA nanocomposites and determining the amount of light scattering and measuring the potential, which were respectively +96.1, 3.77-49.5, they were selected to enter the cell.
Laser scanning microscope observations showed that these composites become a quenching effect in the vicinity of the nucleus and this composite prevents the growth of Helia cells, which depends on the dose and amount of the composites.
Using orange-ethidium bromide staining, it was shown that these nanocomposites cause cell wall apoptosis.
According to a research conducted in 2018 by Fatemeh Hashminejad et al. on the cytocidal effect of the magnetosome of the bacterium Magneto-Spirillium Griffith-Waldnerber on the breast cancer cell line:
It has been shown that magnetic nanoparticles synthesized by magnetic bacteria can be more effective in treating cancer by hyperthermia method than chemically synthesized nanoparticles.
Chemically synthesized nanoparticles are very small and less than 20 nanometers in size.
Conclusion: After preparing the BM-PEI-siRNA nanocomposites and determining the amount of light scattering and measuring the potential, which were respectively +96.1, 3.77-49.5, they were selected to enter the cell.
Laser scanning microscope observations showed that these composites become a quenching effect in the vicinity of the nucleus and this composite prevents the growth of Helia cells, which depends on the dose and amount of the composites.
Using orange-ethidium bromide staining, it was shown that these nanocomposites cause cell wall apoptosis.
According to a research conducted in 2018 by Fatemeh Hashminejad et al. on the cytocidal effect of the magnetosome of the bacterium Magneto-Spirillium Griffith-Waldnerber on the breast cancer cell line:
It has been shown that magnetic nanoparticles synthesized by magnetic bacteria can be more effective in treating cancer by hyperthermia method than chemically synthesized nanoparticles.
Chemically synthesized nanoparticles are very small and less than 20 nanometers in size.
According to the above report, it can be said that the size of the structure of magnetic nanoparticles has a great effect on their effectiveness in dealing with cancer.
The results of various researches show that magnetic nanoparticles enhance the performance of anticancer drugs such as doxorubicin and cisplatin in killing cancer cells through enhancing the production of reactive oxygen species or other unknown mechanisms.
In other words, magnetic nanoparticles increase the cytotoxicity of anticancer drugs and play an important role in drug delivery to tumor cells.
Keywords: Magnetic bacteria - treatment of cancer-cancer