Construction of a MoS2@mSiO2 nanocarrier as a near-infrared/pH dual-responsive platform to control the drug release for anti-tumor

Designing new-type nanosystems to realize the combination of multiple treatment is an efficient routine to enhance the anti-tumor efficacy in clinic. In this study, molybdenum disulfide (MoS 2 ) was selected as a photothermal agent, and mesoporous silica (mSiO 2 ) was coated on the surface of MoS 2 using the solvothermal and template removal methods. The chemotherapeutic drug doxorubicin hydrochloride (DOX) as a model drug was then loaded into the above MoS 2 @mSiO 2 nanocarrier to prepare the tumor-targeting MoS 2 @mSiO 2 -DOX nanosystem. XRD, UV–Vis, FTIR, SEM, TEM, and DLS results jointly confirmed that the MoS 2 @mSiO 2 -DOX nanosystem with a particle size of approximately 370 nm was successfully synthesized. The XPS and BET analysis identified that the outer layer of MoS 2 @mSiO 2 nanocarrier was SiO 2 , which has a large surface area of 99.41 m 2 /g with an average pore size of 3.5 nm coated on the MoS 2 . The in-vitro cytotoxicity and photothermal performance of the MoS 2 @mSiO 2 nanodrug delivery system was tested, and the results show that MoS 2 @mSiO 2 has a low toxicity to normal human liver cells (HL-7702), and which also exhibits a good photothermal stability with a photothermal conversion efficiency of 28.8%. With the aid of the large specific surface area of mSiO 2 and the opposite zeta potential, a high amount of DOX was loaded on MoS 2 @mSiO 2 nanocarrier, and the measured loading efficiency of DOX can reach up to 48.87%. The 48 h-drug release rate of MoS 2 @mSiO 2 -DOX reaches 35.65% under the conditions of near infrared (NIR) laser irradiation at pH=5.0, which is nearly 5 times higher than that of 6.26% under the normal physiological environment (pH=7.4 without NIR laser irradiation), indicating that the MoS 2 @mSiO 2 -DOX nanosystem possesses obvious pH and NIR laser responsive release characteristics. The MoS 2 @mSiO 2 nanocarrier has good cytocompatibility, outstanding photothermal conversion and drug loading properties, and after DOX adsorption, the system exhibits excellent pH and laser responsive drug controlled release performance, which is expected to be widely used in the field of combining the photothermal-chemotherapy to synergistically resist tumor.