UCNP-Bi2 Se3 Upconverting Nanohybrid for Upconversion Luminescence and CT Imaging and Photothermal Therapy.

Non-invasive theranostics that integrate the advantages of multimodality imaging and therapeutics have great potential in the field of biomedicine. Herein, a new nanohybrid based on Bi2 Se3 -conjugated upconversion nanoparticles (UCNPs) has been successfully developed through a simple in situ growth strategy. Under 808 nm near-infrared laser irradiation, the UCNPs can emit bright visible light, whereas the Bi2 Se3 nanomaterial exhibits efficient photothermal conversion capacity. Moreover, the as-synthesized UCNP-Bi2 Se3 nanohybrid exhibits efficient cell upconversion luminescence (UCL), reasonable CT imaging, and admirable cancer cell ablation capacity, further emphasizing the efficiency of this strategy for simultaneous UCL imaging and photothermal therapy. The designed theranostic strategy guided by dual-modal imaging endowed with real-time dynamic monitoring, remote controllability, and non-invasiveness makes the UCNP-Bi2 Se3 nanohybrid an ideal candidate for non-invasive multimodal imaging-guided photothermal therapy for the precise diagnosis and treatment of cancer.

One-pot synthesis of Ln3+-doped porous BiF3@PAA nanospheres for temperature sensing and pH-responsive drug delivery guided by CT imaging.

The design and synthesis of responsive inorganic nanocapsules have attracted intensive research interest in cancer treatment. The combination of non-invasive diagnosis and chemotherapy into a single theranostic nanoplatform is prospective in the biomedical field. In this work, a polyacrylic acid (PAA)-functionalized porous BiF3:Yb,Er nanocarrier was constructed via a straightforward one-pot solvothermal strategy. Compared with the undoped BiF3 sub-microspheres, the lanthanide ion (Ln3+) doping endowed the BiF3 material with a smaller size and increased BET specific surface area and pore volume, which make it suitable as a drug carrier. It was found that the synthesized nanomaterial could effectively relieve the side effects of doxorubicin (DOX) and exhibited pH-dependent DOX loading and release. Its satisfactory biocompatibility and efficient tumor inhibition were emphasized by a series of in vitro/in vivo experiments. In addition, the synthesized nanomaterial exhibited favorable CT contrast efficacy due to the excellent X-ray attenuation coefficient of Bi. Moreover, characteristic upconversion luminescence and temperature sensing in a wide temperature range were realized over the synthesized BiF3:Yb,Er sample. Therefore, carboxyl-functionalized BiF3:Yb,Er can be expected to be an ideal candidate in the fabrication of temperature sensing and multifunctional theranostic nanoplatforms.

Designing of UCNPs@Bi@SiO2 Hybrid Theranostic Nanoplatforms for Simultaneous Multimodal Imaging and Photothermal Therapy.

Herein, a novel multifunctional nanoplatform was designed toward multimodality imaging and photothermal therapy (PTT). It was found that Bi nanoparticles could grow in situ on the surface of NaYF4:20%Yb,2%Er@NaYF4:40%Yb@NaGdF4 core-shell nanoparticles (labeled as UCNPs). In this structure, UCNPs were mainly employed as an upconversion luminescence (UCL) imaging agent, whereas the Bi nanoparticles worked as an effective CT imaging and photothermal agent. Importantly, a dense SiO2 shell was employed to protect the Bi nanoparticles from oxidation, and it also endowed the nanoplatform with excellent hydrophilic ability. The effective UCL/CT imaging and PTT performances were emphasized by a series of in vivo experiments, which suggest that the integrated nanoplatform with imaging and therapy functions shows great promise in the biomedical field.

Facile Synthesis of Lanthanide (Ce, Eu, Tb, Ce/Tb, Yb/Er, Yb/Ho, and Yb/Tm)-Doped LnF3 and LnOF Porous Sub-Microspheres with Multicolor Emissions.

Monodisperse YF3 and YOF porous sub-microspheres were synthesized by using a novel sacrificing template method with amorphous Y(OH)CO3 ⋅x H2 O as the precursors and the template. It was found that the size and shape were well maintained, and the condensed precursor was transformed into uniform porous structures after fluoridation. By fine-tuning the feed of the fluorine source, the final product could be converted from YF3 to YOF. A possible growth mechanism is proposed for the uniform porous YF3 structure and the porous yolk-shell-like YOF structure. The luminescence properties showed that the as-synthesized YF3 :Ln3+ (Ln=Eu, Tb, Ce, Ce/Tb, Yb/Er, Yb/Ho, and Yb/Tm) products exhibited strong multicolor emissions, which included down-/upconversion and energy-transfer processes. Additionally, YOX (X=Cl and Br) could be obtained if a different halogen source was used during calcination. However, the spheres were almost completely destroyed. Our novel synthetic route can also be extended to other lanthanide fluorides (REF3 , RE=Gd, Lu), which may open a facile way to fabricate novel porous nanostructures.

Phase-Tunable Synthesis of Monodisperse YPO4:Ln3+ (Ln = Ce, Eu, Tb) Micro/Nanocrystals via Topotactic Transformation Route with Multicolor Luminescence Properties.

A novel aqueous-based and phase-selected synthetic strategy toward YPO4:Ln3+ (Ln = Ce, Eu, Tb) micro/nanocrystals was developed by selecting specific precursors whose structure topotactically matches with the target ones. It was found that layered yttrium hydroxide (LYH) induced the formation of hexagonal-phased h-YPO4·0.8H2O with the crystalline relationship of [001]LYH//[0001]h-YPO4·0.8H2O, while the amorphous Y(OH)CO3 favored the formation of tetragonal-phased t-YPO4. We also systematically investigated the influence of Na2CO3/NaH2PO4 feeding ratio on the evolutions of morphology and size of the h-YPO4·0.8H2O sample, and we also obtained a novel mesoporous nanostructure for t-YPO4 single crystalline with closed octahedron shape for the first time. Besides, the multicolor and phase-dependent luminescence properties of the as-obtained h-YPO4·0.8H2O and t-YPO4 micro/nanocrystals were also investigated in detail. Our work may provide some new guidance in synthesis of nanocrystals with target phase structure by rational selection of precursor with topotactic structural matching.

Nanoscale {LnIII(24)ZnII(6)} Triangular Metalloring with Magnetic Refrigerant, Slow Magnetic Relaxation, and Fluorescent Properties.

The self-assembly of Ln(ClO4)3 · 6H2O and Zn(OAc)2 · 2H2O with pyrazine-2-carboxylic acid (HL) results in the formation of three novel nanosized {LnIII(24)ZnII(6)} triangular metallorings, [Gd24Zn6L24(OAc)22(µ3-OH)30(H2O)14](ClO4)7(OAc) · 2CH3OH · 26H2O (1), [Tb24Zn6L24(OAc)22(µ3-OH)30(CH3O)2(CH3OH)2(H2O)10](ClO4)5(OH) · 6CH3OH · 12H2O (2), and (H3O)[Dy24Zn6L24(OAc)22(µ3-OH)30(H2O)14](ClO4)7(OAc)2 · 4CH3OH · 22H2O (3), having the largest nuclearity among any known Ln/Zn clusters. Magnetic and luminescent studies reveal the special prowess for each lanthanide complex. Magnetic studies reveal that 1 exhibits a significant cryogenic magnetocaloric effect with a maximum -ΔSm (isothermal magnetic entropy change) value of 30.0 J kg(-1) K(-1) at 2.5 K and 7 T and that a slow magnetization relaxation is observed for the dysprosium analogue. In addition, the solid-state photophysical properties of 2 display strong characteristic Tb(III) photoluminescent emission in the visible region, suggesting that Tb(III)-based luminescence is sensitized by the effective energy transfer from the ligand HL to the metal centers.

Employment of triketones to construct a dysprosium(III) single-molecule magnet.

The initial employment of a triketone ligand in 4f coordination chemistry afforded a series of dinuclear complexes. Magnetic studies revealed that an antiferromagnetic interaction exists in a digadolinium(III) compound, while a dysprosium(III) constructed complex exhibits single-molecule magnet (SMM) behaviour at low temperatures with an energy barrier of 86.8 K.