Hierarchical “Brick-and-Ball” silk fibroin microspheres for mechanically-reinforced cavity filling and photothermal–curcumin synergetic prevention of triple-negative breast cancer recurrence

Shape-complementary microspheres pack into irregular postoperative cavities and act as a local curcumin reservoir. • Hydrated microsphere beds retain integrity during compression, repeated loading and fluid flushing. • Nanosheet content and laser power tune mild heat-assisted curcumin release for local tumor-cell suppression. Postoperative recurrence of triple-negative breast cancer often starts from residual cells left in an irregular lumpectomy cavity, where a short-lived drug depot is easily washed away and a weak filler gives little structural support. We designed injectable SFMA/MXene/curcumin-loaded mesoporous silica nanoparticle (Cur@MSN) microspheres as a cavity-filling chemophotothermal depot rather than a membrane-like wound dressing. XPS confirmed silica-, curcumin- and MXene-associated signals, including Ti-O contributions in the composite. Mechanical tests showed that MXene/MSN reinforcement increased single-particle stiffness and improved hydrated packed-bed compression resistance, cyclic modulus retention and anti-flushing stability. Curcumin release continued for 14 days, and near-infrared irradiation increased the 32 h release from 68.97 ± 0.55% to 82.93 ± 0.45%. Normal 10A and NIH3T3 cells retained high viability, whereas 4 T1 cells showed concentration-dependent inhibition. In vivo thermal screening identified 2.0 mg/mL MXene with 0.50 W/cm 2 irradiation as a mild heating condition (∼43 °C). In a postoperative 4 T1 model, Cur/MXene microspheres with irradiation reduced bioluminescent tumor signals, supporting a locally retained, mechanically reinforced depot for recurrence-oriented therapy. Download: Download high-res image (135KB) Download: Download full-size image