Dechao Niu

Facile Synthesis of Monodisperse Superparamagnetic Fe3O4 Core@hybrid@Au Shell Nanocomposite for Bimodal Imaging and Photothermal Therapy

A simple seed-mediated growth route is developed to fabricate monodisperse, uniform superparamagnetic Fe(3)O(4) core/gold shell structured nanocomposites with tunable sizes and optical properties, in which gold seed formation and attachment onto the core surface via S-Au covalent bonding proceeds almost simultaneously in the one-pot synthesis. The as-prepared nanocomposite is demonstrated to have a great potential for magnetic resonance imaging (MRI)-guided, focused photothermal tumor therapy under near-IR laser radiation.

Synthesis of core-shell structured dual-mesoporous silica spheres with tunable pore size and controllable shell thickness.

Core-shell structured dual-mesoporous silica spheres (DMSS) that possess smaller pores (2.0 nm) in the shell and larger tunable pores (12.8-18.5 nm) in the core have been successfully synthesized by utilizing an amphiphilic block copolymer (polystyrene-b-poly (acrylic acid), PS-b-PAA) and cetyl trimethyl ammonium bromide (CTAB) as cotemplates. The thickness of the shells and the larger pore size in the core could be easily tuned by changing the amounts of TEOS and the hydrophobic block (PS) length during synthesis, respectively. By encapsulating hydrophobic magnetite nanoparticles into the cores, superparamagnetic dual-mesoporous silica spheres were obtained. Drug storage and release testing results showed that the diffusing rate of the stored drug could be efficiently controlled by changing the shell thickness of DMSS.

Monodispersed and Ordered Large-Pore Mesoporous Silica Nanospheres with Tunable Pore Structure for Magnetic Functionalization and Gene Delivery

It can be larger: A facile self-assembly/solvothermal approach to synthesize monodispersed, large-pore (>12 nm) silica nanospheres (LPSNs) with ordered, accessible, and interconnected pore channels has been successfully developed by utilizing an amphiphilic block copolymer (polystyrene-b-poly (acrylic acid), PS-b-PAA) as pore template and cetyltrimethylammonium bromide (CTAB) as structure-stabilizing agent.

Facile Synthesis of Magnetite/Perfluorocarbon Co‐Loaded Organic/Inorganic Hybrid Vesicles for Dual‐Modality Ultrasound/Magnetic Resonance Imaging and Imaging‐Guided High‐Intensity Focused Ultrasound Ablation

Multifunctional organic/inorganic hybrid nanovesicles, fabricated by a facile self-assembly/sol-gel approach, display a unique morphology (figure) and satisfactory stability under physiological conditions. By co-encapsulation of superparamagnetic magnetite nanoparticles and a liquid perfluorocarbon, the nanovesicles can be used not only as a dual-modality ultrasound/magnetic resonance contrast agent for accurate cancer diagnosis and monitoring, but also as a therapeutic enhancement agent for effective high-intensity focused ultrasound (HIFU) ablation.

Dual-Enzyme-Loaded Multifunctional Hybrid Nanogel System for Pathological Responsive Ultrasound Imaging and T2-Weighted Magnetic Resonance Imaging

A dual-enzyme-loaded multifunctional hybrid nanogel probe (SPIO@GCS/acryl/biotin-CAT/SOD-gel, or SGC) has been developed for dual-modality pathological responsive ultrasound (US) imaging and enhanced T2-weighted magnetic resonance (MR) imaging. This probe is composed of functionalized superparamagnetic iron oxide particles, a dual enzyme species (catalase and superoxide dismutase), and a polysaccharide cationic polymer glycol chitosan gel. The dual-modality US/MR imaging capabilities of the hybrid nanogel for responsive US imaging and enhanced T2-weighted MR imaging have been evaluated both in vitro and in vivo. These results show that the hybrid nanogel SGC can exhibit efficient dual-enzyme biocatalysis with pathological species for responsive US imaging. SGC also demonstrates increased accumulation in acidic environments for enhanced T2-weighted MR imaging. Further research on these nanogel systems may lead to the development of more efficient US/MR contrast agents.

A Simple Route to Prepare Monodisperse Au NP-Decorated, Dye-doped, Superparamagnetic Nanocomposites for Optical, MR, and CT Trimodal Imaging

Monodisperse and uniform AuNP-decorated, dye-doped, superparamagnetic nanocomposites (Fe3 O4 @dye-hybrid@Au) are fabricated by using a simple method in which the Au NP formation and their attachment onto the core surface via S-Au covalent bonds proceeds almost simultaneously in a one-pot synthesis. The as-synthesized nanocomposites can simultaneously enhance the contrast effects for MR, CT, and cellular-sensitive optical imaging.

Manganese-Loaded Dual-Mesoporous Silica Spheres for Efficient T1- and T2-Weighted Dual Mode Magnetic Resonance Imaging

A novel class of manganese-based dual-mode contrast agents (DMCAs) based on the core-shell structured manganese-loaded dual-mesoporous silica spheres (Mn-DMSSs) for simultaneous T1- and T2-weighted magnetic resonance imaging (MRI) has been successfully reported. The in vitro MR tests demonstrate that the Mn-based DMCAs display an excellent simultaneous T1-weighted and T2-weighted MR imaging effect with a noticeably high T1 relaxivity (r1) of 10.1 mM(-1) s(-1) and a moderately high T2 relaxivity (r2) of 169.7 mM(-1) s(-1). The Mn-based DMCAs exhibit negligible cytotoxicity with >80% cell viability at a concentration of up to 200 μg/mL in human liver carcinoma (HepG2) and mouse macrophage (RAW264.7) cells after 24 h. Confocal laser scanning microscopy (CLSM) results show that the Mn-DMSSs were internalized via endocytosis and located in the cytoplasm but not in the nucleus. The in vivo experiment shows that the signals of rat liver increased by 29% under T1-weighted imaging mode and decreased by 28% under T2-weighted imaging mode in 5 min postinjection of Mn-DMSSs, which reveal that the novel Mn-loaded DMSSs can be used as both positive (T1-weighted) and negative (T2-weighted) MR contrast agents in further biomedical applications.

Morphology‐Tailoring of a Red AIEgen from Microsized Rods to Nanospheres for Tumor‐Targeted Bioimaging

Efficient morphology modulation of a red AIEgen from pristine microsized rods to nanospheres is achieved via encapsula ting QM-2 (quinolinemalononitrile-2) into hybrid micelles. This novel reagent shows great potential in tumor-targeted bioimaging because of its monodispersion in aqueous systems, the uniform diameter of ≈30 nm, enhanced fluorescence brightness with a large Stokes shift of 190 nm, and strongly increased biocompatibility and photostability.

One-step approach to synthesize hollow mesoporous silica spheres co-templated by an amphiphilic block copolymer and cationic surfactant

Hollow mesoporous silica spheres (HMSSs) with an average diameter of 180 nm and magnetic-functionalized HMSSs have been successfully fabricated via a one-step facile route using the amphiphilic block copolymer polystyrene-block-poly (acrylic acid) (PS215-b-PAA12) and the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) as co-templates.

Highly efficient and selective removal of trace lead from aqueous solutions by hollow mesoporous silica loaded with molecularly imprinted polymers

A novel type of adsorbent for the selective recognition and adsorption of trace Pb2+ from aqueous solutions has been successfully constructed simply by grafting molecularly imprinted polymers (MIPs) onto hollow mesoporous silica (HMS). Attractively, the HMS loaded with MIPs (H-MIPs) exhibits a fast adsorption kinetics, marked adsorption capacity of 40.52mg/g and extremely high selectivity toward Pb2+ over Cu2+, Zn2+, Co2+, Mn2+ and Ni2+, and the selectivity coefficients have been determined to be as high as 50. Moreover, such high adsorptive capability and selectivity were retained for at least 6 runs, indicating the stability and reusability of H-MIPs. Lead ion contaminants in real water samples were successfully concentrated and approximately 100% recovered using H-MIPs. Theoretical analysis shows that the adsorption process of H-MIPs follows the pseudo-second-order kinetic and Langmuir isotherm models. These demonstrate that H-MIPs are greatly potential for the rapid and highly efficient removal of trace Pb2+ ions in complicated matrices.