Yuming Xie,Zicheng Yang,Mengjue Cao,Yi Feng,Jianfeng Yao
So far, direct utilization of zeolitic imidazolate frameworks (ZIFs) as the electrode materials for high-performance supercapacitors (SCs) is challenging owing to their poor electrochemical performance. However, for the first time, the electrochemical activities of ZIFs are found to be dimensional dependent in this study, and can be greatly boosted by reducing the dimension from three-dimension (3D) or two-dimension (2D) to one-dimension (1D). The unique 1D architecture endows 1D ZIF with improved conductivity as well as a high surface-to-volume ratio to facilitate the accessibility of electrolyte ions. Additionally, 1D ZIF is highly defective with abundant linker-missing defects, leading to the favorable exposure of cobalt ions as the redox active sites responsible for pseudocapacitance. Benefiting from these structural and textural merits, 1D ZIF exhibits a much higher charge storage capacity, rate capability and cycling stability than 2D and 3D ZIF. When assembled with activated carbon (AC), the asymmetric supercapacitor device (1D ZIF//AC) can deliver an impressive energy density of 76 Wh kg −1 at a power density of 800 W kg −1 , superior to many other ZIFs, ZIF-based composites, ZIF-derived carbon, and even some advanced metal compounds reported in literature.
To achieve a successful delivery of siRNA by carriers in vivo, the degradation of polymers in response to tiny intracellular changes should be seriously considered. In addition, the balance between degradation and stability of polymers is another key point for high performance of carriers. In this study, imine and disulfide linkages, which are sensitive to pH changes and redox environment, respectively, were constructed as the main backbone of polymers to deliver siRNA at the intracellular and animal level. Comparisons were made between performances of these two different polymers. Both of the polymers synthesized here have good ability to condense siRNA. However, polyplexes formed by the imine backbone-based polymer (TPSP) showed a larger particle size and a higher zeta potential than that of the disulfide backbone-based polymer (DTDPS). Although both TPSP and DTDPS could deliver the target siRNA into 7721 cells, polyplexes formed by TPSP showed a higher silence efficiency in vitro and accomplished more accumulation in tumors. In conclusion, we believe TPSP is superior to be used for siRNA delivery and promises a potential for widespread use.
危险品化学品经营许可证（带存储）