Stimuli-responsive CuS@PMS nanosystem boosts O2-independent antitumor activities of meshes

Reactive oxygen species (ROS) mediated tumor therapeutic strategies have been extensively studied. However, its effectiveness in eliminating tumor cells is inevitably restricted by the hypoxia or the insufficient hydrogen peroxide (H₂O₂) content. To fundamentally address these challenges, an O₂-independent and stimuli-responsive nanosystem (named CuS@PMS) is ingeniously constructed by loading peroxymonosulfate (PMS: HSO₅⁻) into hollow mesoporous copper sulfide (CuS) to mediate the generation of sulfate radicals (SO₄⁻). The CuS@PMS was then introduced into polycaprolactone (PCL) to prepare into breast meshes by selective laser sintering. Specifically, the released Cu²⁺ ions combining with the photothermal property of CuS synergistically activate PMS, ensuring the cascade amplification of SO₄⁻. Unlike conventional ROS, the production of SO₄⁻ independent on the content of O₂ and H₂O₂ in the tumor microenvironment, characterizing a longer half-life and faster reaction rate, thereby possessing more advantages in antitumor. The results showed that the SO₄⁻ yield of PCL/CuS@PMS group significantly higher than that of PCL/PMS group, especially under near-infrared (NIR) light. Moreover, the antitumor efficiency of PCL/CuS@PMS + NIR group was 43 % higher than that of PCL/PMS group in an O₂-independent manner. The study provided a more efficient, highly adaptable and versatile approach for tumor treatment.