Construction and evaluation of a long-circulating thermosensitive liposomal black phosphorus quantum dot delivery system for osteosarcoma therapy

Bone malignant tumors are diseases that endanger human lives and compromise patients' quality of life. Tumors are conventionally treated via chemotherapy; however, nonspecific damage to healthy cells and inefficient targeting of tumor sites often occur, necessitating the development of an innovative treatment paradigm. In this study, a long-circulating thermosensitive liposome encapsulating DOX-loaded BPQDs was constructed to release drugs via pH/NIR response for photothermal-chemotherapy synergistic treatment of osteosarcoma. Initially, BPQDs were synthesized through liquid-phase exfoliation coupled with a solvothermal reaction. Subsequently, DOX was immobilized onto the BPQD surface via electrostatic interactions to ensure efficient chemotherapeutic drug loading. Ultimately, the high-performance Lip-BPQDs-DOX drug delivery system was fabricated by encapsulating BPQDs-DOX within long-circulating thermosensitive liposomes using a thin-film dispersion-extrusion method. The drug delivery system demonstrates a transition in size from large to small, superior photothermal conversion efficiency, pH/NIR-responsive drug release, favorable ex vivo and in vivo biocompatibility, and liposome-mediated, photothermal-chemotherapeutic synergistic anti-tumor effects. These characteristics offer valuable insights for designing multifunctional nanotherapeutic systems for related tumors like osteosarcoma.