<i>In-Situ</i> Crafting of ZnFe₂O₄ Nanoparticles Impregnated within Continuous Carbon Network as Advanced Anode Materials

The ability to create a synergistic effect of nanostructure engineering and its hybridization with conductive carbonaceous material is highly desirable for attaining high-performance lithium ion batteries (LIBs). Herein, we judiciously crafted ZnFe₂O₄/carbon nanocomposites composed of ZnFe₂O₄ nanoparticles with an average size of 16 ± 5 nm encapsulated within the continuous carbon network as anode materials for LIBs. Such intriguing nanocomposites were yielded <i>in situ via</i> the pyrolysis-induced carbonization of polystyrene@poly­(acrylic acid) (PS@PAA) core@shell nanospheres in conjunction with the formation of ZnFe₂O₄ nanoparticles through the thermal decomposition of ZnFe₂O₄ precursors incorporated within the PS@PAA nanospheres. By systematically varying the ZnFe₂O₄ content in the ZnFe₂O₄/carbon nanocomposites, the nanocomposite containing 79.3 wt % ZnFe₂O₄ was found to exhibit an excellent rate performance with high capacities of 1238, 1198, 1136, 1052, 926, and 521 mAh g^–1 at specific currents of 100, 200, 500, 1000, 2000, and 5000 mA g^–1, respectively. Moreover, cycling performance of the ZnFe₂O₄/carbon nanocomposite with 79.3 wt % ZnFe₂O₄ at specific currents of 200 mA g^–1 delivered an outstanding prolonged cycling stability for several hundred cycles

Gadolinium Oxide Nanoparticles and Aptamer-Functionalized Silver Nanoclusters-Based Multimodal Molecular Imaging Nanoprobe for Optical/Magnetic Resonance Cancer Cell Imaging

Multimodal molecular imaging has attracted more and more interest from researchers due to its combination of the strengths of each imaging modality. The development of specific and multifunctional molecular imaging probes is the key for this method. In this study, we fabricated an optical/magnetic resonance (MR) dual-modality molecular imaging nanoprobe, polyethylene glycol-coated ultrasmall gadolinium oxide (PEG-Gd₂O₃)/aptamer-Ag nanoclusters (NCs), for tracking cancer cells. To achieve this aim, PEG-Gd₂O₃ nanoparticles (NPs) as magnetic resonance imaging (MRI) contrast agent and aptamer functionalized silver nanoclusters (aptamer-Ag NCs) as fluorescence reporter were first synthesized by a one-pot approach, respectively. They were then conjugated by the covalent coupling reaction between the carboxyl group on the surface of PEG-Gd₂O₃ NPs and amino group modified on the 5′-end of AS1411 aptamer. With a suitable ratio, the fluorescence intensity of aptamer-Ag NCs and MR signal of PEG-Gd₂O₃ nanoparticles could both be enhanced after the formation of PEG-Gd₂O₃/aptamer-Ag NCs nanoprobe, which favored their application for multimodal molecular imaging. With this nanoprobe, MCF-7 tumor cells could be specifically tracked by both fluorescence imaging and magnetic resonance imaging <i>in vitro.</i

T2-weighted (A) and T2map MR images (B) of NIH-3T3, HLF-1 and HUVEC cells treated with G250-mAb-SPIO nanoprobe, BSA-blocked SPIO nanoparticles, or cell culture medium.

<p>T2-weighted (A) and T2map MR images (B) of NIH-3T3, HLF-1 and HUVEC cells treated with G250-mAb-SPIO nanoprobe, BSA-blocked SPIO nanoparticles, or cell culture medium.</p

Characterization of SPIO nanoparticles.

<p>(A) TEM image of SPIO nanoparticles. (B) Distribution of SPIO nanoparticle size. (C) T2-weighted MR image of SPIO nanoparticles with different concentrations at 3.0 T. With increasing SPIO concentration, the MR image became darker.</p

FT-IR spectra of mAb G250-SPIO nanoprobes (green line), SPIO nanoparticles (black line), and mAb G250 (red line).

<p>FT-IR spectra of mAb G250-SPIO nanoprobes (green line), SPIO nanoparticles (black line), and mAb G250 (red line).</p

UV-vis absorption spectra of mAb G250-SPIO nanoprobes (blue line), SPIO nanoparticles (red line), and mAb G250 (black line).

<p>The emergence of absorption peak of mAb G250 in the mAb G250-SPIO nanoprobe indicates the successful fabrication of specific MR imaging nanoprobe.</p

Cell viability of 786-0 renal carcinoma cells (A) and normal human umbilical vein endothelial cells (B) after exposure to various concentrations of SPIO nanoparticles, as determined by a CCK-8 assay.

<p>Cell viability of 786-0 renal carcinoma cells (A) and normal human umbilical vein endothelial cells (B) after exposure to various concentrations of SPIO nanoparticles, as determined by a CCK-8 assay.</p

T2-weighted and T2map MR images of 786

<p>-<b>0 renal carcinoma cells treated with mAb G250-SPIO nanoprobe, IgG-SPIO nanoprobe, SPIO nanoparticles, or culture medium.</b></p

MRI stability test of BSA-blocked SPIO nanoparticles in cell culture medium for various hours. (1) BSA-blocked SPIO nanoparticles were dispersed in PBS for 1 h.

<p>(2)–(4) BSA-blocked SPIO nanoparticles were dispersed in cell culture medium for 1 h, 5 h, and 24 h. (5) pure 30% gelatin solution.</p

T2 relaxation time of NIH-3T3 cells, HLF-1 cells and HUVEC cells treated with G250-mAb-SPIO nanoprobe, BSA-blocked SPIO nanoparticles or culture medium.

<p>T2 relaxation time of NIH-3T3 cells, HLF-1 cells and HUVEC cells treated with G250-mAb-SPIO nanoprobe, BSA-blocked SPIO nanoparticles or culture medium.</p