Ultrasmall FeCo-graphitic carbon shell nanocrystals （FeCo/GC） are promising multifunctional materials capable of highly efficient drug delivery in vitro and magnetic resonance imaging in vivo. In this work, we demon...Ultrasmall FeCo-graphitic carbon shell nanocrystals （FeCo/GC） are promising multifunctional materials capable of highly efficient drug delivery in vitro and magnetic resonance imaging in vivo. In this work, we demonstrate the use of FeCo/GC for highly effective cancer therapy through combined drug delivery, tumor-selective near-infrared photothermal therapy, and cancer imaging of a 4T1 syngeneic breast cancer model. The graphitic carbon shell of the ~4 nm FeCo/GC readily loads doxorubicin （DOX） via π-π stacking and absorbs near-infrared light giving photothermal heating. When used for cancer treatment, intravenously administrated FeCo/GC-DOX led to complete tumor regression in 45% of mice when combined with 20 min of near-infrared laser irradiation selectively heating the tumor to 43-45 ℃. In addition, the use of FeCo/GC-DOX results in reduced systemic toxicity compared with free DOX and appears to be safe in mice monitored for over 1 yr. FeCo/GC-DOX is shown to be a highly integrated nanoparticle system for synergistic cancer therapy leading to tumor regression of a highly aggressive tumor model.展开更多
Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, t...Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, the obtained functional magnetic microspheres as heterogeneous catalysts showed superior performance in catalyzing the epoxidation of styrene with extraordinary high conversion （89.5%） and selectivity （90.8%） towards styrene oxide. It is believed that the construction process of these fascinating materials features many implications for creating other functional nanocomposites.展开更多
Strain engineering is a powerful tool to tailor the physical properties of materials coherently stacked in an epitaxial heterostructure. Such an approach, applied to the mature field of planar heteroepitaxy, has yield...Strain engineering is a powerful tool to tailor the physical properties of materials coherently stacked in an epitaxial heterostructure. Such an approach, applied to the mature field of planar heteroepitaxy, has yielded a variety of new phenomena and devices. Recently, heteroepitaxial vertically aligned nanocomposites have emerged as alternatives to planar structures. Owing to the peculiar geometry of such nanoarchitectures, efficient strain control can be achieved, opening the way to novel functionalities. In this paper, we report a very large tensile axial strain in epitaxial transition metal nanowires embedded in an oxide matrix. We show that axial strains in excess of 1.5% can be sustained over a large thickness （a few hundred nanometers） in epitaxial nanowires having ultrasmall diameters （-3-6 nm）. The axial strain depends on the diameter of the nanowires, reflecting its epitaxial nature and the balance of interface and elastic energies. Furthermore, it is experimentally shown that such strain is metastable, in agreement with the calculations performed in the framework of the Frenkel-Kontorova model. The diameter dependence and metastability provide effective ways to control the strain, an appealing feature for the design of functional nanoarchitectures.展开更多
文摘Ultrasmall FeCo-graphitic carbon shell nanocrystals （FeCo/GC） are promising multifunctional materials capable of highly efficient drug delivery in vitro and magnetic resonance imaging in vivo. In this work, we demonstrate the use of FeCo/GC for highly effective cancer therapy through combined drug delivery, tumor-selective near-infrared photothermal therapy, and cancer imaging of a 4T1 syngeneic breast cancer model. The graphitic carbon shell of the ~4 nm FeCo/GC readily loads doxorubicin （DOX） via π-π stacking and absorbs near-infrared light giving photothermal heating. When used for cancer treatment, intravenously administrated FeCo/GC-DOX led to complete tumor regression in 45% of mice when combined with 20 min of near-infrared laser irradiation selectively heating the tumor to 43-45 ℃. In addition, the use of FeCo/GC-DOX results in reduced systemic toxicity compared with free DOX and appears to be safe in mice monitored for over 1 yr. FeCo/GC-DOX is shown to be a highly integrated nanoparticle system for synergistic cancer therapy leading to tumor regression of a highly aggressive tumor model.
文摘Magnetic yolk-shell structured anatase-based microspheres were fabricated through successive and facile sol-gel coating on magnetite particles, followed by annealing treatments. Upon loading with gold nanoparticles, the obtained functional magnetic microspheres as heterogeneous catalysts showed superior performance in catalyzing the epoxidation of styrene with extraordinary high conversion （89.5%） and selectivity （90.8%） towards styrene oxide. It is believed that the construction process of these fascinating materials features many implications for creating other functional nanocomposites.
文摘Strain engineering is a powerful tool to tailor the physical properties of materials coherently stacked in an epitaxial heterostructure. Such an approach, applied to the mature field of planar heteroepitaxy, has yielded a variety of new phenomena and devices. Recently, heteroepitaxial vertically aligned nanocomposites have emerged as alternatives to planar structures. Owing to the peculiar geometry of such nanoarchitectures, efficient strain control can be achieved, opening the way to novel functionalities. In this paper, we report a very large tensile axial strain in epitaxial transition metal nanowires embedded in an oxide matrix. We show that axial strains in excess of 1.5% can be sustained over a large thickness （a few hundred nanometers） in epitaxial nanowires having ultrasmall diameters （-3-6 nm）. The axial strain depends on the diameter of the nanowires, reflecting its epitaxial nature and the balance of interface and elastic energies. Furthermore, it is experimentally shown that such strain is metastable, in agreement with the calculations performed in the framework of the Frenkel-Kontorova model. The diameter dependence and metastability provide effective ways to control the strain, an appealing feature for the design of functional nanoarchitectures.
