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Polymeric micelles are frequently used to transport and deliver drugs throughout the body because they protect against degradation. Research on functional polymeric micelles for biomedical applications has generally shown that micelles have beneficial properties, such as specific functionality, enhanced specific tumor targeting, and stabilized nanostructures. The particular aim of this study was to synthesize and characterize multifunctional polymeric micelles for use in controlled drug delivery systems and biomedical imaging. In this study, a theranostic agent, doxorubicin/superparamagnetic iron oxide (SPIO)-encapsulated Pluronic F127 (F127) micelles, was developed for dual chemotherapy/magnetic resonance imaging (MRI) purposes, and the structure and composition of the micellar SPIO were characterized by transmission electron microscopy and magnetic measurements. Our results revealed that the micellar SPIO with a diameter of around 100 nm led to a significant advantage in terms of T2 relaxation as compared with a commercial SPIO contrast agent (Resovist (R)) without cell toxicity. After doxorubicin encapsulation, a dose-dependent darkening of MR images was observed and HeLa cells were killed by this theranostic micelle. These findings demonstrate that F127 micelles containing chemotherapeutic agents and SPIO could be used as a multifunctional nanocarrier for cancer treatment and imaging. (c) 2010 American Institute of Physics. [doi:10.1063/1.3357344

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The growth kinetics of amorphous interlayers (a interlayers) formed by solid-state diffusion in ultrahigh vacuum deposited polycrystalline Ti thin films on germanium and epitaxial Si1−xGex (x=0.3, 0.4 and 0.7) alloys grown on (001) Si and (111) Ge has been investigated by transmission electron microscopy and Auger electron spectroscopy. The growth of a interlayers in all systems was found to follow a linear growth behavior initially. The activation energies for the linear growth of a interlayers were found to decrease with the Ge content and are 1.0±0.2, 0.95±0.2, 0.85±0.2, and 0.7±0.2 eV for Ti/Si0.7Ge0.3, Ti/Si0.6Ge0.4, Ti/Si0.3Ge0.7, and Ti/Ge systems, respectively. The maximum thickness of a interlayer was found to increase with the Ge content with x⩽0.4. On the other hand, the formation temperature of crystalline phase was observed to decrease with the Ge content. Essential factors for the formation and growth of a interlayer are discussed. The results are compared with the Ti/Si system.

The phase formation and the morphological stability of ε1-Cu3Ge and ε1-Cu3(Si1−xGex) in Cu/epitaxial-Ge(e-Ge)/(111)Ge, Cu/(001)Ge, Cu/e-Ge/(111)Si, and Cu/(001)Si–Ge alloys have been investigated by transmission electron microscopy in conjunction with the energy dispersive spectrometry as well as by sheet resistance measurement. Epitaxial Cu and epitaxial ζ-Cu5Ge were found to form in as-deposited Cu/e-Ge/(111)Ge and Cu/e-Ge/(111)Si. On the other hand, textured Cu was found to form in the other systems. Polycrystalline ε1-Cu3Ge and ε1-Cu3(Si1−xGex) were the only phases formed in 150–500 °C annealed Cu/Ge and (Cu/e–Ge/Si and Cu/Si–Ge alloys) systems, respectively. They were found to agglomerate at 550 °C. The room-temperature oxidation of substrate in the presence of Cu3(Si1−xGex) was found only in the Cu/Si0.7Ge0.3 system. From the sheet resistance measurement, ε1-Cu3Ge has the lowest resistivity of 7 μΩ cm after 400 °C annealing. The electrical resistivity was found to decrease with the Ge content.