Polydopamine-Coated Self-Assembled Lipid Nanoparticles for Highly Effective Chemo–Photothermal Combination Therapy

Chemo–photothermal combination therapy is an emerging clinical treatment method, which shows favorable application prospects in clinical practice. However, various drug delivery systems have certain disadvantages, and it is urgent to overcome the existing disadvantages and combine the advantages of different delivery systems. In this study, we have designed and synthesized a novel core–shell polymer-coated lipid-core nanoparticle drug delivery system for chemo–photothermal therapy. The designed drug delivery system is based on electrostatic self-assembled polylysine-lecithin (PLL-LC) lipid nanoparticles to encapsulate antitumor or anti-inflammatory drugs and then coated with polydopamine (PDA) shell for chemo–photothermal combination therapy. The self-polymerized PDA coated on the surface of nanomicelles under weak alkaline conditions can form a responsive drug delivery system. As expected, the prepared core–shell nanoparticles showed good photothermal properties and good potential for thermal ablation of tumor cells. Moreover, the release of chemotherapeutic drugs under the modification of polydopamine has the corresponding pH and NIR stimulation. In vitro drug release and cell experiments demonstrated that our designed nanoparticles could achieve pH- and NIR-stimulation-responsive drug release and exhibit enhanced tumor cytotoxicity under laser irradiation. Taken together, our study demonstrates that designed nanoparticles can be used for pH/NIR-responsive sustained release and chemo–photothermal synergistic treatment.