NIR-triggered release of DOX from sophorolipid-coated mesoporous carbon nanoparticles with the phase-change material 1-tetradecanol to treat MCF-7/ADR cells.

To prevent premature drug release from nanoparticles, it is vital to design and prepare controlled and site-specific drug release systems. We investigated a new controllable drug release mesoporous carbon nanoparticle (MCN)-based nano-system with the advantages of enhanced permeability and retention effect (EPR) to target tumors followed by the NIR-induced heat-triggered release of a chemotherapeutic drug to show anti-tumor effects. The pores of MCN with photo-thermal effects were filled with the chemotherapeutic agent doxorubicin (DOX) and the phase change material (PCM) 1-tetradecanol was used as a gatekeeper to trap DOX inside the pores of the mesoporous carbon nanoparticles and the release of DOX inside tumor cells was triggered using NIR irradiation. The surface of MCN was coated with natural sophorolipid (SLPD) to obtain nanoparticles (DOX-PCM@MCN-SLPD) with good biocompatibility, dispersibility and stability in aqueous solutions. The MCN-based nano-system had the ability to load 24% DOX trapped with the PCM before coating with SLPD. It was observed that the release of DOX was temperature-dependent above the melting point of PCM. Once DOXPCM@MCN-SLPD was delivered into MCF-7/ADR cells, the release of DOX was triggered by MCN-borne photo-thermal effects under NIR irradiation. The amount of DOX inside the tumor was visualized via confocal laser scanning microscopy, which showed a higher amount of DOX at a higher temperature compared to that at normal body temperature, further confirming the minimization of premature drug release at 37 °C.