Subject Number : S-16-NM-0113
Support Type : 共同研究
Proposal Title (English) : Development of MOF nanoparticles for drug delivery
Username (English) : Yufang Zhu
Affiliation (English) : University of Shanghai for Science and Technology, China

1. Summary
Mesoporous silica nanoparticles (MSNs) are widely considered to be efficient drug delivery nanocarriers. Graphene quantum dots (GQDs) are biocompatible, and can effectively convert NIR light energy into heat, potentially acting as a photothermal agent. In this work, the GQD−MSNs nanoparticles were prepared for synergistic chemo− photothermal therapy because MSNs function as a nanocarrier for controlled drug release and GQDs function as photothermal agents for photothermal therapy.

2. Experimental
In this work, we tested in vitro cytotoxicity, cell uptake of the GQD-MSNs nanoparticles using CCK-8 assay and CLSM observation. On the other hand, we also tested the therapeutic efficiency of the DOX-loaded GQD-MSNs nanoparticles by CCK-8 assay. The detailed experimental methods are described in the published papers.

Cell culture works were done at NIMS MMS PF.

3. Results and Discussion
To evaluate the biological safety of the GQD−MSNs, the 4T1 cells were used as a cellular system to investigate the cytotoxicity of GQD−MSNs in vitro, measured by a CCK-8 assay. The result showed that the cell viabilities were not significantly different between the concentrations from 0 to 200 μg/mL after incubation of 4T1 cells with the GQD−MSNs for 24 h.
Cell uptake of DOX−GQD−MSNs nanoparticles was carried out by incubation of 4T1 cells with DOX−GQD−MSNs for 4 and 8 h. Red fluorescence signal from the DOX molecules was observed in the nuclei, which we attribute to DOX release from the DOX−GQD−MSNs before and after endocytosis by 4T1 cells, suggesting that the 4T1 cells internalize DOX−GQD−MSNs.
To evaluate the synergistic effect of DOX−GQD−MSNs on therapeutic efficiency, the viability of the 4T1 cells after 8 h treatment by free DOX, GQD−MSNs, and DOX−GQD−MSNs, without and with 3 min NIR irradiation, was tested. When NIR irradiation was applied to 4T1 cells after incubation with DOX−GQD−MSNs, cell viability significantly decreased to 11%, and it is much lower than that of GQD−MSNs with NIR irradiation, suggesting that DOX−GQD−MSNs, as a multifunctional platform, can achieve synergistic therapeutic efficiency through chemo−photothermal therapy.

4. Others
We thank Prof. Nobutaka Hanagata for discussing the experimental data.

5. Publication/Presentation
(1) Xianxian Yao, Zhengfang Tian, Jiaxing Liu, Yufang Zhu*, Nobutaka Hanagata*, Mesoporous Silica Nanoparticles Capped with Graphene Quantum Dots for Potential Chemo−Photothermal Synergistic Cancer Therapy. Langmuir, 2017, 33, 591−599.

6. Patent
N/A