Drug-Loaded Microspheres on NIR-Responsive PLA/MXene Scaffolds: Controlled Release and Bone Tissue Regeneration.

The resection of bone tumors results in large bone defects with some residual tumor cells, and the treatment of this type of bone defect area often faces a dilemma, namely, the trade-off between bone repair and antitumor after the resection of bone tumors. In order to promote local bone repair, and at the same time inhibit tumor recurrence by continuous and controlled drug administration, we developed a multifunctional NIR-responsive scaffold, whose main components are polylactic acid and MXene, and loaded with PLGA/DOX microspheres, and we hope that the scaffold can take into account both antitumor and bone repair in the bidirectional modulation effect of NIR. The results showed that the scaffold with 1% MXene content had relatively good performance in photothermal therapy (PT) and other aspects, and it could be smoothly increased to 50 °C within 2 min under NIR illumination, and the drug release of microspheres was increased by 10% after illumination compared with that at body temperature. In vivo experiments in animals showed that this scaffold effectively limited the in situ recurrence of tumor cells and lung metastasis and was able to promote osteogenic differentiation under NIR irradiation. Therefore, this scaffold can not only control the release of antitumor drugs but also enhance the antitumor effect through the bidirectional modulation effect of PT and at the same time promote bone formation, which provides a good application solution for the integrated treatment of the bone defect area after bone tumor surgery.