Preparation and evaluation of near-infrared and pH dual-responsive mesoporous carbon nanospheres for controlled drug release

In this study, a multifunctional nanoplatform was developed. Mesoporous carbon nanospheres were prepared using silica microspheres as hard templates through a hard-template method. Low molecular weight polyethyleneimine and succinic anhydride were grafted onto the spheres through amidation reactions to obtain near-infrared and pH dual-responsive mesoporous carbon nanospheres for targeted controlled drug release and photothermal therapy. The successful preparation of the nanocomposites with a particle size of approximately 120 nm was confirmed by SEM and TEM. The in-vitro cytotoxicity and photothermal performance were evaluated, and the results showed that the carrier exhibited low toxicity, with a survival rate of 91.94 % for mouse macrophages (RAW264.7). Additionally, the carrier demonstrated excellent photothermal stability with a photothermal conversion efficiency of 39.05 % and a maximum temperature increase of 39.6 °C. Drug adsorption tests revealed that the carrier's maximum equilibrium adsorption capacity for curcumin was 133.3 mg L −1 . In-vitro drug release experiments showed that the release performance could be controlled by pH and near-infrared laser irradiation. Under conditions of pH = 6 and near-infrared light, the cumulative drug release rate was 15.1 %. The excellent targeting, curcumin loading, and release performance of the carrier offer new possibilities for integrating photothermal therapy with chemotherapy for synergistic tumor treatment.