Chemicals involving solvents, Coenzyme Q0 (2,3-Dimethoxy-5-methyl-p-benzo- quinone), ammonia solution (25%), (3-Mercaptopropyl) and trimethoxysilane were acquired from sigma (Switzerland) Company. Iron (II) chloride and Iron (III) chloride and tetraethyl ortho silicate were purchased from Merck (Germany) Company. All the chemicals were used without further purification.
Equipment
1HNMR spectrum was recorded on a Bruker 400 MHz. IR spectra were recorded on a Perkin-Elmer FT-IR-1710 spectrophotometer with the samples in KBr pellets. The plates of biological samples were read using Elisa reader (Ratio-China) at 570 nm. Biological results were calculated statistically using SPSS 17 and Microsoft Excel and presented as mean ± SD in triplicate experiment. Differences in the results were determined at significant difference of 0.05 (P≤ 0.05). FESEM was recorded on a Hitachi S4160 instrument (Tokyo, Japan). TGA were determined using Perkin-Elmer Pyris Diamond and Pyris 6 TGA Consumables, respectively under a nitrogen atmosphere at a heating rate of 10 ˚C min-1.
Synthesis of conjugated 3-(trimethoxysilyl) propane-1-thiol to 2,3,5-trimethoxycyclohexa-2,5-diene-1,4-dione (Q0) (Silanized Q0):
For the synthesis of the silanized Q0, firstly, 0.024 g Na was dissolved in 10 cc methanol and then 3-(trimethoxysilyl)propane-1-thiol (0.2 cc, 1.06 mmol) was added to the methoxide/methanol solution, and after 30 min Q0 (0.194 gr, 1.06 mmol) was added to the prepared mixture. Color of the solution was changed from light to dark brown. The reaction stayed at the same condition overnight under N2 atmosphere. Then, methanol was evaporated under reduced pressure and crude brown solid was washed at first with methanol to remove sodium methoxide and then with acetone for removal of excess raw materials to reach the pure silanized Q0 (0.3 gr).
IR (as KBr pellet): 683 cm-1 (C-S bond), 1112 cm-1 (broad peak related to C-O and Si-O bonds), 1250 cm-1 (C-C bond), 1331 cm-1 (CH3 groups), 1460 cm-1 (CH2 group), 1645 cm-1 (C = C bond), 1693 and 1750 cm-1 (C = O bond), 2930 cm-1 (C-H).
1HNMR: 0.91 ppm (t, CH2), 1.05 ppm (Q, CH2), 1.24 ppm (t, CH2), 1.65 ppm (s, Si-OMe), 3.17 ppm (s, -OMe), 3.56 ppm (s, -OMe), 3.75 ppm (d, C-H), 3.95 ppm (d, C-H).
Preparation of Fe3O4-SiO2 (Silicated Fe3O4)
For preparation of the silicated nanomagnetic particles, 2 gr Fe
3O
4 (
22) was dispersed on 50 cc distilled water and sonicated for 15 min. Then, 1 cc TEOS solved in 9 cc distilled water, added to the aqueous mixture of the Fe
3O
4. 3 gr glycerol and also some drops of glacial acetic acid were added to the mixture to reach the pH 4.5. To reach the temperature up to 90 ºC, agitation of the mixture was continued for 2 h. Then, silicated nanomagnetic particles were removed by magnet and washed three times with water and acetone respectively to remove any non-supported material and reagents. The nanoparticles were dried in vacuum at 50 ºC overnight (2.8 gr).
IR (as KBr pellet): 550-600 cm-1 (Fe-O-Fe bond), 1050-1100 cm-1 (broad peak related to Si-O bonds), 3400-3500 cm-1 (O-H bonds)
Preparation of the immobilized Q0 onto the silicated Fe3O4 (Fe3O4-SiO2-Q0)
0.6 g of the silicated Fe3O4 was added to the 25 cc H2O and sonicated for 15 min. Then 0.3 gr (0.79 mmol) silanized Q0 that had been solved in 2 cc DMSO was added to the mixture. 1.5 cc glycerol and some drops of acetic acid were added to the above mixture to reach to the pH 4.5. After that, the mixture stirred for 2 h at 90 ºC. Then, by using magnet, the synthesized particles were collected and washed with DMSO, water, and acetone. At the end, wet powder was dried in vacuum oven at 40 ºC overnight (0.8 gr).
IR (as KBr pellet): about 630 cm-1 (Fe-O-Fe bond), 1038 cm-1 (broad peak related to C-O and Si-O bonds), 1425 cm-1 (CH2 group), 1632 cm-1 (C = C bond), 1745 cm-1 (C = O bond), 2925 cm-1 (C-H bond), 3421 cm-1 (O-H bond).
Cell culture
The cell culture and primary human Fibroblasts isolation were performed according to the previous published article (
28). Briefly, The HeLa (The human cervix cancer cell line), Saos (Sarcoma osteogenic cells), and MCF-7 (human breast adenocarcinoma cell line) were obtained from national cell bank of Iran (NCBI, Pasteur Institute of Iran). In 5% CO
2 at 37 °C with 95% humidity of air, the cell lines were cultured in RPMI-1640 (Sigma-Aldrich, Germany) and fortified with 10% fetal bovine serum FBS (Gibco/Invitrogen), and 1% penicillin and streptomycin (Sigma-Aldrich, USA). After washing with PBS, the culture medium was changed each two days. This process was completed with 10 mL of fresh culture medium for 2-5 passage.
MTT Assay
The HeLa, MCF-7, and Saos cell lines were cultured in 96-well plates (104 cells/well). Afterwards, 200 μL culture medium containing 10% (μg/mL) FBS was added to each wells. Under standard protocol, the culture medium was removed and the cells were treated with fresh ones containing different concentration of nanoparticles. After being in an incubator for 24, 48, and 72 h, 200 μL of the culture medium was removed and 50 μL of MTT (5mg/mL) solution was added to the wells. After appropriate time, the previous MTT solution was replaced with 200 μL of MTT solvent (acidic isopropanol) for solubilization of the formazan crystals. Subsequently, the mean absorbance of the plate was measured using elisa reader at 570 nm.