Polydopamine-Based Composite Nanoparticles with Redox-Labile Polymer Shells for Controlled Drug Release and Enhanced Chemo-Photothermal Therapy

Photothermal therapy (PTT) that utilizes phSUPPotothermal conversion agents (PTC) to ablate tumor under NIR light irradiation has attracted increasing attention due to its excellent therapeutic efficacy and improved target selectivity. Herein, a novel core-shell nanoparticle based on disulfide-crosslinked poly(methacrylic acid) (PMAA) layer coated polydopamine (PDA) particle has been successfully synthesized by precipitation polymerization. For these PDA@PMAA composite nanoparticles, PDA core exhibits high photothermal efficacy, meanwhile, the redox-labile PMAA shell serves as carriers to encapsulate anticancer drugs and selectively release them. Due to the characteristic of the disulfide bond, PMAA shell occurs at selective degradation as well as controlled drug release upon entering cancer cells. Moreover, the DOX-loaded PDA@PMAA nanoparticles demonstrated a synergistic effect, which shows a significantly improved inhibition effect against cancer cells by the combination of photothermal therapy and traditional chemotherapy with low drug dosage and short laser irradiation in an in vitro study.