One-pot preparation of pH- and redox-responsive polymeric microgel as an efficient carrier for improved breast cancer therapy

Nano -drug carriers responsive to external stimuli have attracted greater scientific attention for the treatment of cancer. In this study, biodegradable DPA-DSDMA-PEG microgels were prepared as a drug delivery system via emulsion polymerization while using Doxorubicin (DOX) as the model drug. In this system, Bis(2methacryloyloxyethyl) Disulfide (DSDMA) served as redox responsive cross -linker, 2-(Diisopropylamino) ethyl methacrylate (DPA) acted as monomers, and Poly (ethylene glycol) methyl ether methacrylate (PEG) was used as hydrophilic shells. The inclusion of PEG imparts excellent stability and good anti -fouling properties to the prepared microgel. Moreover, the microgels displayed dual pH/redox responsiveness, attributed to the pH sensitivity of DPA and the presence of disulfide bonds of DSDMA. Similarly, MTT assays showed that the DPADSDMA-PEG microgels displayed low cytotoxicity, even at concentrations of up to 100 mu g/mL. Further, DOX@DPA-DSDMA-PEG inhibited the proliferation of 4T1 cells. In vivo studies showed that DOX@DPA-DSDMAPEG microgels significantly enhanced the suppression of tumor growth. This work offers a promising strategy to design and develop dual -responsive and biocompatible nanomaterials for the treatment of cancer.