- [Show abstract] [Hide abstract] ABSTRACT: In the work, a novel multifunctional silica-based nanoplatform (Pd@Ag@SiO22(RITC)-R8) for bioimaging and photothermal therapy (PTT) of cancer cells has been developed. The Pd@Ag nanosheets encapsulated inside silica can act as effective near-infrared (NIR) absorbers for cancer photothermal therapy. Fluorescent dye, rhodamine B isothiocyanate (RITC), was covalently doped into the silica network to provide the capacity for optical imaging. After amine modification, the Pd@Ag@SiO2(RITC)–NH2 can be further conjugated with octaarginine (R8, a cell penetrating peptide) for enhancing the uptake of nanoparticles by cells. Confocal fluorescent images and flow cytometry analysis revealed that R8-conjugated nanoparticles (Pd@Ag@SiO2(RITC)-R8) were taken up by cells more efficiently. Correspondingly, the optical imaging and photothermal therapeutic efficiency of Pd@Ag@SiO2(RITC)-R8 upon cancer cells were also raised due to their higher cellular uptake when compared with that of Pd@Ag@SiO2(RITC)–NH2. Our results indicate that these multifunctional Pd@Ag@SiO2(RITC)-R8 may have great potential for applications in imaging-guided cancer photothermal therapy.
- [Show abstract] [Hide abstract] ABSTRACT: In this work, we prepared chlorin e6 (Ce6)-functionalized Pd nanosheets (Pd-PEI-Ce6) for the photodynamic and photothermal combined therapy that use a single laser. In order to fabricate the Pd-PEI-Ce6 nanocomposite, photosensitizer Ce6 were chemically conjugated to polyethyleneimine (PEI) and the formed Ce6-PEI conjugates were then anchored onto Pd nanosheets by electrostatic and coordination interaction. The prepared Pd-PEI-Ce6 nanocomposite were about 4.5 nm in size, exhibited broad and strong absorption from 450 nm to 800 nm, good singlet oxygen generation capacity and photothermal conversion efficiency, and excellent biocompability. Signiﬁcantly greater cell killing was observed when HeLa cells incubated with Pd-PEI-Ce6 were irradiated with the 660 nm laser, attributable to both Pd nanosheets-mediated photothermal ablation and the photodynamic destruction effect of photosensitizer Ce6. The double phototherapy effect was also confirmed in vivo. It was found that the Pd-PEI-Ce6 treated tumor-bearing mice displayed the enhanced therapeutic efficiency compared to that of Pd-PEI, or Ce6-treated mice. Our work highlights the promise of using Pd nanosheets for potential multi-mode cancer therapies.
- [Show abstract] [Hide abstract] ABSTRACT: The preparation, characterization and application of NaYF4:Yb3+, Tm3+–NaYF4:Yb3+, Er3+ core–shell upconversion nanocrystals (UCNPs) with multiple emission peaks (e.g. 539, 654 and 802 nm) have been demonstrated in this work. The monodisperse nanocrystals were prepared via a modified thermal decomposition synthesis. The resulting UCNPs were 31 nm in diameter with the lanthanide ions Tm3+ and Er3+ doped in the core and the shell, respectively. Under the laser diode excitation at 980 nm, these core–shell nanocrystals give strong upconversion emissions from the visible to near-infrared (NIR) region. By coating a PEG–phospholipid (PP) layer on the surface of the nanocrystals, the as-prepared UCNPs were favorably endowed with good water solubility for the potential biological applications. Here, a photosensitizer drug of Chlorin e6 (Ce6), which has maximum absorption that overlaps with the red emission of UCNPs, was loaded on these PP-coated UCNPs (UCNP@PP) by physical adsorption. The activity of the Ce6-loaded UCNP@PP (UCNP@PP–Ce6) in photodynamic therapy of cancer cells in vitro has been fully investigated in this work. Our results indicated that these multifunctional UCNP@PP–Ce6 nanoparticles have efficient NIR-to-NIR upconversion luminescence and photodynamic therapy capabilities, which could be potentially employed as a theranostic platform for cancer treatment.
- [Show abstract] [Hide abstract] ABSTRACT: In this work, we have demonstrated that mesoporous silica-coated Pd@Ag nanoparticles (Pd@Ag@mSiO2) can be used as an excellent nanoplatform for photodynamic therapy (PDT) drug delivery. Photosensitizer molecules, Chlorin e6 (Ce6), are covalently linked to the mesoporous shell and the prepared Pd@Ag@mSiO2–Ce6 nanoparticles exhibit excellent water solubility, good stability against leaching and high efficiency in photo-generating cytotoxic singlet oxygen. More importantly, the photothermal effect of Pd@Ag nanoplates under the irradiation of a NIR laser can enhance the uptake of Pd@Ag@mSiO2–Ce6 nanoparticles by cells, further increasing the PDT efficiency toward cancer cells. The photothermally enhanced PDT effects were demonstrated both in vitro and in vivo. When the Pd@Ag@mSiO2–Ce6 nanoparticles were injected intratumorally into the S180 tumor-bearing mice, the tumors were completely destroyed without recurrence of tumors upon irradiation with both 808 nm and 660 nm lasers, while the irradiation with 808 nm or 660 nm alone did not. These results indicate that the Pd@Ag@mSiO2 nanoparticles may be a valuable new tool for application in cancer phototherapy.
- [Show abstract] [Hide abstract] ABSTRACT: Lanthanide-doped upconversion nanoparticles (UCNPs) have attracted considerable attention for their application in biomedicine. Here, silica-coated NaGdF(4):Yb,Er/NaGdF(4) nanoparticles with a tetrasubstituted carboxy aluminum phthalocyanine (AlC(4)Pc) photosensitizer covalently incorporated inside the silica shells were prepared and applied in the photodynamic therapy (PDT) and magnetic resonance imaging (MRI) of cancer cells. These UCNP@SiO(2)(AlC(4)Pc) nanoparticles were uniform in size, stable against photosensitizer leaching, and highly efficient in photogenerating cytotoxic singlet oxygen under near-infrared (NIR) light. In vitro studies indicated that these nanoparticles could effectively kill cancer cells upon NIR irradiation. Moreover, the nanoparticles also demonstrated good MR contrast, both in aqueous solution and inside cells. This is the first time that NaGdF(4):Yb,Er/NaGdF(4) upconversion-nanocrystal-based multifunctional nanomaterials have been synthesized and applied in PDT. Our results show that these multifunctional nanoparticles are very promising for applications in versatile imaging diagnosis and as a therapy tool in biomedical engineering.
- [Show abstract] [Hide abstract] ABSTRACT: A synthetic method to prepare novel multifunctional core-shell-structured mesoporous silicananoparticles for simultaneous magnetic resonance (MR) and fluorescence imaging, cell targeting and photosensitization treatment has been developed. Superparamagnetic magnetite nanoparticles and fluorescent dyes are co-encapsulated inside nonporous silicananoparticles as the core to provide dual-imaging capabilities (MR and optical). The photosensitizer molecules, tetra-substituted carboxyl aluminum phthalocyanine (AlC4Pc), are covalently linked to the mesoporous silica shell and exhibit excellent photo-oxidation efficiency. The surface modification of the core-shell silicananoparticles with folic acid enhances the delivery of photosensitizers to the targeting cancer cells that overexpress the folatereceptor, and thereby decreases their toxicity to the surrounding normal tissues. These unique advantages make the prepared multifunctional core-shell silicananoparticles promising for cancer diagnosis and therapy.
Amoy, Fujian, China
- Department of Chemistry