Reduction-sensitive flower-like magnetomicelles based on PCL-ss-PEG-ss-PCL triblock copolymer as anti-cancer drug delivery system

Introducing an intelligent pharmaceutical nanocarrier for targeted drug release and reducing the side effects of chemotherapy is the main goal of many researchers. In this area, we synthesized amphiphilic triblock copolymer PCL-ss-PEG-ss-PCL consisting of cystamine as a reduction sensitive linkage. The aqueous self-assembly of triblock copolymer in the presence of magnetic iron oxide nanoparticles (Fe3O4) and doxorubicin (DOX) led to the for-mation of reduction-sensitive flower like magnetomicelle containing DOX and Fe3O4. The innovative design based on intelligent flower like structure led to high drug loading content, reduce drug release in physiologic condition, fast degradation at targeted site and burst release of more content of drug at earlier time. The DOX loading content was about 19% and DOX-loaded magnetomicelles (D-LMM) showed more triggered release under redox conditions at pH = 5. The efficiency of D-LMM was compared with non-reduction sensitive control group (CD-LMM), free DOX and commercial product of liposomal DOX (LD) in vitro. The D-LMM showed sig-nificant improvement in cellular uptake and toxicity behavior on human breast adenocarcinoma MCF-7 cells in comparison to commercial LD and also displayed better results in the cytotoxicity and apoptosis/necrosis assays in comparison to CD-LMM.