MgSiO₃ Fiber Membrane Scaffold with Triggered Drug Delivery for Osteosarcoma Synergetic Therapy and Bone Regeneration

In this research, a novel MgSiO₃ fiber membrane (MSFM) loaded with indocyanine green (ICG) and doxorubicin (DOX) was prepared. Because of MgSiO₃'s unique lamellar structure composed of a silicon-oxygen tetrahedron, magnesium ion (Mg²⁺) moves easily and can be further replaced with other cations. Therefore, because of the positively charged functional group of ICG, MSFM has a rather high drug loading for ICG. In addition, there is electrostatic attraction between DOX (a cationic drug) and ICG (an anionic drug). Hence, after loading ICG, more DOX can be adsorbed into MSFM because of electrostatic interaction. The ICG endows the MSFM outstanding photothermal therapy (PTT) performance, and DOX as a chemotherapeutic drug can restrain tumor growth. On the one hand, H⁺ exchanged with the positively charged DOX based on the MgSiO₃ special lamellar structure. On the other hand, the thermal effect could break the electrostatic interaction between ICG and DOX. Based on the above two points, both tumor acidic microenvironment and photothermal effect can trigger DOX release. What's more, in vitro and in vivo antiosteosarcoma therapy evaluations displayed a superior synergetic PTT-chemotherapy anticancer treatment and excellent biocompatibility of DOX&ICG-MSFM. Finally, the MSFM was proven to greatly promote cell proliferation, differentiation, and bone regeneration performance in vitro and in vivo. Therefore, MSFM provides a creative perspective in the design of multifunctional scaffolds and shows promising applications in controlled drug delivery, antitumor performance, and osteogenesis.