Thermo- and pH-responsive copolymer poly(t-butyl acrylate)-b-poly{[2-(dimethylamino) ethyl methacrylate]-co-[poly(ethylene glycol) methyl ether methacrylate]}: Preparation, characterization, and their applications as organic dye adsorbents and drug delivery systems

Temperature and pH double-response poly(t-butyl acrylate)- b -poly{[2-(dimethylamino) ethyl methacrylate]- co -[poly(ethylene glycol) methyl ether methacrylate]} (PtBA -b- P(DMAEMA- co -PEGMEMA)) were successfully prepared by RAFT polymerization and could be self-assembled into micelles . 1 H NMR, UV-vis absorbance and DLS measurements were used to characterize their structures and self-assembly behaviors. At the same time, the adsorption of organic dyes and the control of drug release were also introduced. The results showed that the critical micelle concentration of PtBA- b -P(DMAEMA- co -PEGMEMA) was 2.55 mg/L. As the value of pH increased from 2 to 11, their particle size decreased from 178 nm to 130 nm. PtBA- b -P(DMAEMA- co -PEGMEMA) was also temperature responsive, with the hydrophobic block grows, the temperature of the particle mutation would increase. Therefore, PtBA- b -P (DMAEMA- co -PEGMEMA) could control the transfer and release of organic dyes such as methyl red and dithizone through their pH-sensitive properties, and the process had good reversibility. Meanwhile, PtBA- b -P(DMAEMA- co -PEGMEMA) micelles could also deliver some specific hydrophobic anticancer drug , such as camptothecin (CPT). In conclusion, the copolymers synthesized in this work have potential applications in the fields of environmental protection and drug delivery.