Dual-ResponsiveDual-Drug-Loaded Bioinspired PolydopamineNanospheres as an Efficient Therapeutic Nanoplatform against Drug-ResistantCancer Cells

Multidrug resistance evoked by overusing pharmaceuticals of poor water solubility has posed a serious threat to public health, which urges the development of safe and efficacious therapeutic formulations. In this study, biomimetic nanospherical polydopamine (PDA) formed under mild conditions was modified using methoxypolyethylene glycol amine (m-PEG-NH2) to produce a polydopamine-based drug delivery platform. As characterized by various physicochemical methods, the PEGylated PDA with a uniform size distribution showed superior biocompatibility and efficient load capability for two hydrophobic anticancer drugs of paclitaxel and phytochemical curcumin, which exhibited synergistic cytotoxicity and a pH/ROS-responsive release behavior. Significantly, an enhanced effect of the encapsulated paclitaxel and curcumin was identified toward the drug-resistant A549/TAX cancer cells, which was correlated with the improved cellular internalization of hyperbranched PDA composites and distinctive cell cycle arrest of loaded drugs. The dual-drug-loaded spherical PDA nanocomposites hold enormous potential to tackle drug resistance from a chemotherapy perspective.