Preparation Of R/MoS₂/Doxorubicin Targeted Nanodrug Delivery System And Antitumor Activity In Vitro

Objective:To prepare a biocompatible nanodrug loading system consisting of RGD/MoS₂/DOX that integrates targeted delivery,thermal therapy and chemotherapy,thereby improving the ability of killing cancer cells while reducing the toxic and side effects.Methods:MoS₂ nanosheets were initially synthesized and used as the substrate material.Targeted modification of MoS₂ with RGD and covalently coupling of a classical anticancer drug,DOX,led to the formation of the nanodrug loading system,RGD/MoS₂/DOX composite.In this way,targeted chemotherapy and thermal effect can be well combined to strengthen the anticancer function in vitro.The major experimental methods include:（1）MoS₂nanosheets were synthesized by hydrothermal method.Then lipoic acid functionalized polyethylene glycol carboxylic acid served to connect MoS₂ and RGD（Arg-Gly-Asp,a targeted recognition unit）by amide coupling reaction.SPDP,a linker was then chemically binding to the precedingly prepared composite material,forming the nanocarrier,MPRS.Further,thiolated DOX was tethered to the as-prepared nanocarrier,ultimately producing the nanodrug,MPRS-DOX;（2）The prepared nanomaterials were extensively characterized by many characterization methods.The photothermal effect,stability and biocompatibility of MPRS were investigated,and the drug loading,release performance and targeting efficacy of MPRS-DOX were evaluated.Finally,the antitumor effect of thermo-chemotherapy with MPRS-DOX nanodrug delivery system in vitro was researched.Results:（1）MoS₂ nanosheets were successfully prepared.（2）FT-IR,XPS and UV-vis analyses verified the formation of MPRS-DOX.The obtained nanodrug had a drug-loading quantity of 53.5%and the drug-loading efficiency reached 86.8%.Moreover,GSH-induced cleavage of the disulfide bond facilitated the release of DOX from the MPRS-DOX composite.In a p H 5.5buffer containing 10 m M GSH,DOX can be effectively released.（3）MPRS exhibited favorable photothermal conversion efficiency and stability.The photothermal properties were dependent on the concentration of nanocarrier and the intensity of near-infrared light power,which both showed a positive correlation.（4）Cytotoxicity results indicated that the cell survival rates were more than 80%when H9c2 cell,VSMC cells,Hela cells and MCF-7 cells were cultured in the MPRS nanocarrier for 48 h,suggesting that the prepared MPRS nanocarrier had good biocompatibility to the cells.Moreover,we found that Hela cells could endocytose more MPRS-DOX than H9c2 cells and MCF-7 cells,It shows that MPRS-DOX has good targeting property to Hela cells.（5）When exposed to the MPRS-DOX nanodrug for 48 h（with DOX concentration of 10μg/m L）,the survival rate of Hela cells was found to be 22.23±1.22%.By contrast,the survival rate of Hela cells dramatically decreased to 8.9±1.42%when in combination with NIR irritation,suggesting that MPRS-DOX had dual thermal and chemical effects for killing tumor cells.The cell apoptosis experiment and scratch test further confirmed the synergistic thermo-chemotherapy anti-tumor activities in vitro.Conclusion:The prepared MPRS-DOX nanodrug delivery system realized targeted chemotherapy and synergistic thermal therapy,thus offering a means for design of high-efficiency and low-toxicity antitumor nanodrug.