TPAOH assisted size-tunable Gd2O3@mSi core-shell nanostructures for multifunctional biomedical applications.

We report a facile and large-scale synthesis of size-tunable and nontoxic mesoporous silica-coated Gd2O3:Eu3+ (Gd@mSi) core-shell nanostructures using a TPAOH assisted modified UHP technique. The role of TPAOH in controlling the particle size was evaluated. The potentiality of these Gd@mSi core-shell nanoparticles before and after folic acid conjugation was established by in vitro fluorescence microscopy of the U2OS cell lines for cancer imaging and therapy.

Preparation of Eu3+ ions activated Ca2La8(SiO4)6O2 oxyapatite nanophosphors through two-step surfactant-free method and their optical and electrical properties.

Eu3+ ions activated Ca2La8(SiO4)6O2 (CLSO):Eu3+ nanophosphor samples were synthesized by a mixed solvothermal and hydrothermal method. The samples were carefully studied using various characterization techniques. The XRD patterns of CLSO:Eu3+ and CLSO confirmed that the samples were crystallized in hexagonal phase with a space group of P63/m (176). The morphology of the nanoparticles was studied by varying the reaction parameters such as growth, temperature and time. The photoluminescence (PL) excitation and PL emission spectra exhibited the typical Eu3+ bands in the wavelength range of 200-550 nm and 400-750 nm, respectively. The intensity of the [Formula: see text] electric dipole (ED) transition peak was strong in the PL emission spectrum which imparts the red color when observed under ultraviolet light. The ED transition peak intensity increased when the sample was calcined at an elevated temperature of 700 °C, indicating improved asymmetry ratio and good chromaticity coordinates. The electrical properties of the prepared materials were studied by spin-coating the powder dispersed solutions on the silica substrate. The output current values were also measured for the CLSO nanoparticles prepared under different growth conditions. These results showed the advantages of CLSO nanoparticles for their application in optics and feasibility in nanoelectronic and energy harvesting devices.

Multifunctional nanoparticles: recent progress in cancer therapeutics.

Although much progress has been made in treating cancers, cancer death rates in and around the United States are still high. Current treatments are either ineffective against some cancers or detrimental to patients, which decreases their quality of life. The use of nanotechnology in cancer therapy can potentially increase patient survival, reduce side effects, and reduce mortality rates because nanoparticles (NPs) have the potential to target only tumors and bypass healthy cells. NPs possess many features, including size, shape, charge, and composition, which allow them to carry chemotherapeutics to cancer cells. NPs can also be used in radiotherapy as radiosensitizers and in imaging as contrast agents. Many studies have performed in vitro and/or in vivo experiments on these particles in human and animal cell lines. This review discusses recent studies on different NPs and their potential use in cancer therapy.

Pechini synthesis of lanthanide (Eu3+/Tb3+or Dy3+) ions activated BaGd2O4 nanostructured phosphors: an approach for tunable emissions.

Trivalent lanthanide (Eu(3+), Tb(3+) and Dy(3+)) ions activated tunable color emitting BaGd2O4 (BG) phosphors were synthesized by a facile Pechini-type sol-gel process. The X-ray diffraction pattern confirmed the orthorhombic phase after annealing at 1300 °C for 5 h. Morphological studies were performed based on the analysis of transmission electron microscopy images, which showed needle type nanorods. The BG phosphor exhibited good photoluminescence (PL) properties in the respective regions when doped with Eu(3+), Tb(3+) and Dy(3+) ions. The Eu(3+) co-activated BG:Tb(3+) phosphor yielded tunable emissions including tri-band established white light emission based on the co-activator concentration and excitation wavelength. The energy transfer from Tb(3+) to Eu(3+) ions was controlled by selecting a suitable excitation wavelength and the decay measurements were carried out for analyzing the energy transfer efficiency. The cathodoluminescence properties of these phosphors were almost similar to PL properties when doped with individual Eu(3+), Tb(3+), and Dy(3+) ions, but were different when co-doped with Eu(3+)/Tb(3+) or Eu(3+)/Dy(3+) ions. In the case of Eu(3+)/Tb(3+) doped samples, the energy transfer process occurred unlike the PL channel. The calculated Commission International de l'Eclairage chromaticity coordinates of individual ion doped BG phosphors confirmed red, green, and white emissions and for co-doped samples they showed tunable emission.

Cross-relaxation induced tunable emissions from the Tm(3+)/Er(3+)/Eu(3+) ions activated BaGd2O4 nanoneedles.

Tm(3+), Er(3+), Tm(3+)/Er(3+), Tm(3+)/Er(3+)/Eu(3+) single, double and triple activator ion/ions doped nanocrystalline BaGd2O4 (BG) phosphors were prepared by a Pechini type sol-gel process. After annealing at 1300 °C, X-ray diffraction patterns confirmed their orthorhombic structure. Field-emission transmission electron microscope images of the BG sample indicated a nanoneedle-type morphology. Photoluminescence (PL) and cathodoluminescence (CL) measurements were utilized to establish the emission properties of rare-earth ions doped nanocrystalline BG host lattice. Under near-ultraviolet (NUV) excitations, BG:Tm(3+) and BG:Er(3+) exhibited their characteristic emissions in the blue and green regions, respectively, while BG:Tm(3+)/Er(3+) and BG:Tm(3+)/Er(3+)/Eu(3+) showed cyan and white light emissions, respectively, when doped with appropriate amounts of activator ions. In the PL, the cross-relaxation process is dominant rather than the energy transfer process. Due to the different mechanism from PL, the CL spectra showed different emission features of BG:Tm(3+)/Er(3+)/Eu(3+) phosphor. The CL spectra of BG:Tm(3+) and BG:Er(3+) established the high purity blue and green emissions, respectively. From the PL and CL investigations, the white-light emission was realized from the single-phase BG:Tm(3+)/Er(3+)/Eu(3+) phosphor under NUV and low voltage electron beam excitations.

Novel orange and reddish-orange color emitting BaGd2O4:Sm3+ nanophosphors by solvothermal reaction for LED and FED applications.

BaGd2O4 (BG):Sm(3+) nanophosphors were synthesized by a solvothermal reaction method. The powder X-ray diffraction pattern confirmed their orthorhombic structure, and the morphological studies were carried out by taking the scanning and transmission electron microscopy images. The photoluminescence (PL) emission and PL excitation (PLE) spectra were investigated as a function of Sm(3+) ion concentration. The PLE spectra revealed both Gd(3+) and Sm(3+) excitation bands in the shorter and longer wavelength regions, indicating that the efficient energy transfer occurred from the Gd(3+) to Sm(3+) ions in the BG host lattice. The PL spectra exhibited an intense orange emission due to ((4)G5/2→(6)H7/2) transition along with two other moderate intense emission peaks due to the ((4)G5/2→(6)H5/2) and ((4)G5/2→(6)H9/2) transitions. Based on the emission performance related to ((4)G5/2→(6)H7/2) transition, the Sm(3+) ion concentration was optimized to be at 1 mol%. The low-voltage cathodoluminescent (CL) measurements were also performed for BG:1 mol% Sm(3+) nanophosphors as a function of accelerating voltage and filament current. From the CL spectra, the reddish-orange emission was observed. The Commission International De I-Eclairage chromaticity coordinates of BG:Sm(3+) nanophosphors were found to be very close to the chromaticity coordinates of Nichia Corporation developed amber light-emitting diodes.

Imaging and curcumin delivery in pancreatic cancer cell lines using PEGylated α-Gd2(MoO4)3 mesoporous particles.

Mesoporous particles are emerging as multifunctional biomaterials for imaging and drug delivery in several disease models, including cancer. We developed PEGylated α-Gd2(MoO4)3 marigold flower-like mesoporous particles for the purpose of drug delivery and, more specifically, evaluated their ability to deliver curcumin. The obtained mesoporous particles significantly conjugated the curcumin particles on their surfaces by inducing the formation of curcumin nanoparticles. In vitro studies of the PEGylated mesoporous particles filled with curcumin demonstrated that these particles could considerably facilitate the continuous and sustained release of curcumin into the cytoplasm and nucleus. As a result, the intracellular release of curcumin can inhibit proliferation in two human pancreatic cancer cell lines: MIA PaCa-2 and PANC-1. Additionally, the particles showed the increased inhibition of pIKKα, pIKKα/ß and NF-κB-DNA binding activity as compared to pure curcumin. The curcumin conjugated mesoporous particles are concentrated in the cytoplasm and nucleus of the treated cancer cell lines. Consequently, these mesoporous particles are an effective method for drug delivery that can cross the biological barriers of the body targeting the cellular nucleoplasm.