Smart Vesicle Kit for In Situ Monitoring of Intracellular Telomerase Activity Using a Telomerase-Responsive Probe

A smart vesicle kit was designed for in situ imaging and detection of cytoplasmic telomerase activity. The vesicle kit contained a telomerase primer (TSP) and a Cy5-tagged molecular beacon (MB) functionalized gold nanoparticle probe, which were encapsulated in liposome for intracellular delivery. After the vesicle kit was transfected into cytoplasm, the released TSP could be extended in the presence of telomerase to produce a telomeric repeated sequence at the 3′ end, which was just complementary with the loop of MB assembled on probe surface. Thus, the MB was opened upon hybridization to switch the fluorescent state from “off” to “on”. The fluorescence signal depended on telomerase activity, leading to a novel strategy for in situ imaging and quantitative detection of the cytoplasmic telomerase activity. The cytoplasmic telomerase activity was estimated to be 3.2 × 10^–11, 2.4 × 10^–11, and 8.6 × 10^–13 IU in each HeLa, BEL tumor and QSG normal cell, respectively, demonstrating the capability of this approach to distinguish tumor from normal cells. The proposed method could be employed for dynamic monitoring of the cytoplasmic telomerase activity in response to a telomerase-based drug, suggesting the potential application in discovery and screening of telomerase-targeted anticancer drugs

In Situ Growth of Core–Sheath Heterostructural SiC Nanowire Arrays on Carbon Fibers and Enhanced Electromagnetic Wave Absorption Performance

Large-scale core–sheath heterostructural SiC nanowires were facilely grown on the surface of carbon fibers using a one-step chemical vapor infiltration process. The as-synthesized SiC nanowires consist of single crystalline SiC cores with a diameter of ∼30 nm and polycrystalline SiC sheaths with an average thickness of ∼60 nm. The formation mechanisms of core–sheath heterostructural SiC nanowires (SiC_nws) were discussed in detail. The SiC_nws-CF shows strong electromagnetic (EM) wave absorption performance with a maximum reflection loss value of −45.98 dB at 4.4 GHz. Moreover, being coated with conductive polymer polypyrrole (PPy) by a simple chemical polymerization method, the SiC_nws-CF/PPy nanocomposites exhibited superior EM absorption abilities with maximum RL value of −50.19 dB at 14.2 GHz and the effective bandwidth of 6.2 GHz. The SiC_nws-CF/PPy nanocomposites in this study are very promising as absorber materials with strong electromagnetic wave absorption performance