Electroporation figured prominently as an effective nonviral gene delivery approach for its balance on the transfection efficiency and cell viability, no restrictions of probe or cell type, and operation simplicity. The commercial electroporation systems have been widely adopted in the past two decades while still carry drawbacks associated with the high applied electric voltage, unsatisfied delivery efficiency, and/or low cell viability. By adding highly conductive gold nanoparticles (AuNPs) in electroporation solution, we demonstrated enhanced electroporation performance (i.e. better DNA delivery efficiency and higher cell viability) on mammalian cells from two different aspects: the free, naked AuNPs reduce the resistance of the electroporation solution so that the local pulse strength on cells was enhanced; targeting AuNPs (e.g., Tf-AuNPs) were brought to the cell membrane to work as virtual microelectrodes to porate cells with limited area from many different sites. The enhancement was confirmed with leukemia cells in both a commercial batch electroporation system and a home-made flow-through system using pWizGFP plasmid DNA probes. Such enhancement depends on the size, concentration, and the mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increased 2-3 folds at minimum sacrifice of cell viability. This new delivery concept, the combination of nanoparticles and electroporation technologies, may stimulate various in vitro and in vivo biomedical applications which rely on the efficient delivery of nucleic acids, anticancer drugs, or other therapeutic materials.

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Aptamer‐capped, drug‐loaded metal‐organic framework nanoparticles (NOMFs) are synthesized by a click chemistry method by Itamar Willner and co‐workers in article number https://doi.org/10.1002/adfm.201702102. The NOMFs are unlocked by ATP, which is overexpressed in cancer cells, leading to high cytotoxic efficacy and targeted drug release to MDA‐MB‐231 breast cancer cells.

In this article, an affordable split‐and‐recombine polymer static micromixer and its fabrication process are described. The structure of the micromixer was designed to take advantage of the process capabilities of both ultraprecision micromachining and microinjection molding. This arrangement allows a considerably short machining time, high productivity, and flexibility as compared with many of the previous fabrication processes used in manufacturing of micromixers, for example, the cleanroom process. Moreover, in recent years, microinjection molding has become a cost effective mass production method for polymeric components with micro and nano scale features. Specifically, in this study four dominating processing parameters in microinjection molding, including melt temperature, injection velocity, packing pressure, and packing time were selected as variables to investigate their effects on replication quality. Both experimental and numerical results showed that the packing pressure and packing time played an important role on replication, followed by melt temperature while the injection velocity seemed to have no influence on replication. Finally, experiments using two colored water solutions were conducted to evaluate the device performance, and the mixing result demonstrated the successful fabrication and performance of the injection molded polymer micromixer. POLYM. ENG. SCI., 50:1594–1604, 2010. © 2010 Society of Plastics Engineers