Nana Li,Xuanyuan Wen,Jing Liu,Baoju Wang,Qiuqiang Zhan,Sailing He
UCNP-based drug delivery systems commonly rely on stimuli-sensitive auxiliaries, lacking a straightforward manipulation strategy. Here we designed Yb3+-enhanced upconversion/mesoporous silica nanocomposites (UCNP@SiO2) for consecutive cell imaging, photothermal drug delivery and cancer therapy. Core UCNPs (NaYbF4: 2% Er3+) were synthesized and coated with mesoporous silica, whose high-efficiency photothermal properties were verified in vitro. Then doxorubicin hydrochloride (DOX) was loaded on the UCNP@SiO2 and successfully triggered to release by a 975 nm laser of 150 mW or 300 mW. Before the therapy, we used a much lower laser power of 15 mW (which would cause little DOX release) for UCNP-probed fluorescence imaging of Hela cells and affirmed a favorable cell uptake of nanocomposites. Subsequently, cell viability assay and PI stain have demonstrated that the 300 mW laser could manipulate drug delivery of UCNP@SiO2-DOX and cause a severe loss of cell viability. The Yb3+-enhanced UCNP@SiO2 shows a great potential in simultaneous biomedical imaging and photothermal-triggered on-site drug delivery for chemotherapy of cancer.
Junping Zhang,Fuyao Liu,Tao Li,Xiuxia He,Zhenxin Wang
Taking advantage of the unique optical properties of upconversion nanoparticles (NP) and the feasibly modified nature of SiO2, NaYF4:Yb3+, Er3+@SiO2 core@shell (UCNP@SiO2) NPs with excellent morphology have been synthesized to investigate the surface charge effect on the interactions of NPs with cells. The cellular uptake behaviors, cytotoxicities and intracellular metal ion release of the as-prepared NPs have been investigated in two cell lines (HeLa and HepG-2) by fluorescence microscopy, MTT assay and inductively coupled plasma mass spectrometry (ICP-MS), respectively. It is found that the UCNP@SiO2 NPs with positive surface charge have much higher cell internalization ability and cytotoxicity than those with negative surface charge. The experimental results also demonstrate that the cytotoxicity of UCNP@SiO2 NP is closely related to the increase of intracellular reactive oxygen species (ROS) and metal ion release of internalized NPs.
危险品化学品经营许可证（带存储）