A historical overview of the activation and porosity of MOFs including strategies to design and preserve permanent porosity in MOFs.

Solar electricity is an unlimited source of sustainable fuels, yet the efficiency of solar cells is limited. The efficiency of perovskite solar cells improved from 3.9% to reach 25.5% in just a few years. Perovskite solar cells are actually viewed as promising by comparison with dye-sensitized solar cells, organic solar cells, and the traditional solar cells made of silicon, GaAs, copper indium gallium selenide (CIGS), and CdTe. Here, we review bare and doped metal oxide electron transport layers in the perovskite solar cells. Charge transfer layers have been found essential to control the performance of perovskite solar cells by tuning carrier extraction, transportation, and recombination. Both electron and hole transport layers should be used for charge separation and transport. TiO 2 and 2,2′,7,7′-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene are considered as the best electron and hole transport layers. Metal oxide materials, either bare or doped with different metals, are stable, cheap, and effective.

We describe a novel antibiotic delivery system based on magnetic nanoparticles (NPs) conjugated to a cell-penetrating peptide (CPP).

To further improve the efficiencies of the established drugs, various treatment strategies, such as preparation of protein-drug conjugates and the design of nanoscale drug-carriers, are used to increase the efficacy of therapeutic agents. [6-8] Several effective nanocarrier systems were designed to deliver anti-cancer cytotoxic agents to tumor cells with high selectivity and efficacy while minimizing negative side effects. [9,10] Drug nano-carriers provide multiple advantages, such as convenient uptake and internalization, reduced drug interactions, optimized lifetime, and widened therapeutic windows. [11] In this regard, the synthetic design and applications of different types of iron oxide nanoparticles (Fe 3 O 4 NPs) have received significant attention since these NPs can be magnetically directed inside target tissues and their surface can be easily functionalized with diverse polymers and organic compounds. [12-16] Previously, we have reported several magnetic systems in micro-and nanoscale for diverse functional applications. [17-24] To further expand upon this work, we utilized one of the most commonly employed polymers, polyvinyl alcohol (PVA), to encapsulate magnetic Fe 3 O 4 NPs by virtue of its extended hydrogen bonding and to provide a selective release medium for DXL. [25] Drug molecules, such as DXL, can be incorporated into a PVA gel when polymer chains are in a shrunk state at low temperatures, and subsequently released in a target tissue upon a PVA transition into a swollen gel at 37 °C. [26] PVA features several important advantages. First is the ability to form a gel owing to multiple hydrogen bonding by OH groups. A versatile breast cancer-targeting nanocomposite therapeutic combining docetaxel (DXL), polyvinyl alcohol (PVA) network for controlled release, and silica-protected magnetic iron oxide nanoparticles (Fe 3 O 4 NPs) for targeted delivery and gold nanoparticles (AuNPs) for plasmonic photothermal therapy (PPTT) is presented in this work. First, the designed nanocomposite is magnetically directed for cancer-targeted therapy confirmed by computerized tomography (CT) scans. Second, 10% DXL by mass is loaded into PVA, a pH and temperature responsive gel, for controlled release. Third, PPTT is confirmed with Au/Fe 3 O 4 /PVA-10%DXL using a prototype circulation system and then for tumor treatment in vivo; Au/Fe 3 O 4 /PVA-10%DXL is conveniently directed and the entrapped DXL is selectively released (≈96%) via the interaction of green and near-infrared (NIR) light with the localized surface plasmon resonance of AuNPs. A 75% cell death is reported from in vitro studies with DXL doses as low as 20 µg mL −1 of Au/Fe 3 O 4 /PVA-10%DXL, and a 70% tumor growth inhibition is demonstrated by in vivo experiments with the biosafety studies confirming minimal side effects to other organs. Overall, the developed Au/Fe 3 O 4 /PVA-10%DXL has a strong potential to simultaneously enhance CT imaging contrast together with the targeted delivery of DXL.

No abstract