Synthesis Of The Macro PEG-RAFT Agent (CTA)

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Synthesis of PEG-RAFT agent
The synthesis of the macro PEG -RAFT agent, Chain Transfer Agent (CTA), was performed by esterification method. Briefly, RAFT agent (0.4 g, 1.5 mmol) and dihydroxyl PEG (2g, 0.5 mmol) were dissolved in 35 mL of DCM in a 250 mL round bottom flask equipped with a magnetic stirrer. Then, it was placed in an ice bath (0 ºC); Next, DCC (0.25 g, 1.2 mmol) and DMAP (0.015 g, 0.12 mmol) were added. After 30 min of stirring at 0 °C, the reaction temperature is elevated to room temperature. The reaction mixture stirred for 2 days. The precipitated dicyclohexylurea was separated by filtration. The mixture was concentrated by rotary evaporator and then, was precipitated into additional diethyl ether twice to remove the unreacted
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For synthesis of Poly [(PMA-PNIPAM)m-b-PEG-b-(PNIPAM- PMA)m] triblock triblock terpolymer, PEG-RAFT agent (0.45 g, 0.11 mmol), NIPAM (2.0 g, 17.7 mmol), methacrylic acid (1.5 g, 17.7 mmol) and AIBN (3.6 mg, 0.022 mmol) were dissolved in THF (4mL) in a 100 mL round bottom flask. After deoxygenation of the solution, the reaction flask temperature is raised to 70 °C and stirred for 24 h. After 24 h, the reaction flask was cooled to ambient temperature and was opened to air in order to stop the polymerization reaction. The reaction mixture was decanted into excess diethyl ether. The produce was purified twice by dissolution/ precipitation with dichloromethane/diethyl ether and then dried in a vacuum for 24 h. (2.34 g, 82%) (Scheme1 …show more content…
the lung cancer cell (A549) were treated with varying concentrations of the triblock triblock terpolymer, DOX-loaded magnetic nanocomposite, and free DOX then incubated for 24, 48 and 72 h. Control experiments were performed using PBS instead of triblock triblock terpolymer/ Fe3O4/ DOX or free DOX solutions. Then, the medium of all wells was removed carefully and 60 μl of MTT was added to each well and plate was incubated for 4 h in dark. After incubation, wells content were removed and 100μl pure DMSO and 25μl Sorensen's glycine buffer was added to wells to dissolve the formazan crystals. Immediately, the absorbance of each well was read at 570 nm by ELISA plate reader at a reference wavelength of 630nm (34). The half-maximal inhibitory concentration (IC50) was determined as the DOX concentration that resulted in a 50% reduction in cell viability and was calculated using the following

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