Comparative Evaluation of Lipofectamine and Dendrimer for Transfection of Short RNA Into Human T47D and MCF-10A Cell Lines

Purpose: Non-viral transfection approaches are extensively used in cancer therapy. The future of cancer therapy lies on targeted and efficient drug/gene delivery. The aim of this study was to determine the transfection yields of two commercially available transfection reagents (i.e. Lipofectamine 2000, as a cationic lipid and PAMAM G5, as a cationic dendrimer) in two breast cell lines: cancerous cells (T47D) and non-cancerous ones (MCF-10A). Methods: We investigated the efficiencies of Lipofectamine 2000 and PAMAM G5 for transfection/delivery of a labeled short RNA into T47D and MCF-10A. In addition to microscopic assessments, the cellular uptakes of the complexes (fluorescein tagged-scrambled RNA with Lipofectamine or PAMAM dendrimer) were quantified by flow cytometry. Furthermore, the safety of the mentioned reagents was assessed by measuring cell necrosis through the cellular PI uptake. Results: Our results showed significantly better efficiencies of Lipofectamine compared to PAMAM dendrimer for short RNA transfection in both cell types. On the other hand, MCF-10A resisted more than T47D to the toxicity of higher concentrations of the transfection reagents. Conclusion: Altogether, our research demonstrated a route for comprehensive epigenetic modification of cancer cells and depicted an approach to efficient drug delivery, which eventually improves both short RNA-based biopharmaceutical industry and non-viral strategies in epigenetic therapy

Oxazolium Iodide Modified Perovskites for Solar Cell Fabrication

Perovskites solar cells are gaining interest due to their attractive solar-to-electricity conversion efficiencies; however, they suffer from certain problems, such as suboptimal ion migration and stability issues. We report here on the inclusion of a phenyloxazolium salt (2-phenyl-3-methyloxazolium iodide) in perovskite solar cells based on methyl ammonium lead triiodide (MAPbI(3)). The fabricated solar cells not only displayed improved photovoltaic properties, but importantly the oxazolium cations can protect the perovskite layers from UV exposure as they down-convert electromagnetic irradiation; that is, the photons in the UV are absorbed and re-emitted at a different wavelength. The loading of 2-phenyl-3-methyloxazolium iodide in the perovskite precursor solution was optimized, the resulting perovskite films characterized, and the solar cells fabricated from them evaluated for their performance. Overall, this simple approach serves to optimize the performance parameters of perovskites films for solar cell applications

Principal Descriptors of Ionic Liquid Co-catalysts for the Electrochemical Reduction of CO2

Electrochemical reduction of carbon dioxide (CO2RR) is promoted by ionic liquid (IL) co-catalysts, and several mechanisms have been proposed to explain their role. Due to the complexity of the CO2RR and the limited number of active IL co-catalysts, a consensus on the precise role of ILs has not been reached, and it is not possible to improve their activity in a rational way. Herein, we describe guanidinium (Gua) ILs that act as co-catalysts for the CO2RR when employed in non-aqueous electrolytes. The peripheral substituents of the Gua cation were systematically modified allowing the IL co-catalytic properties to be fine-tuned, and on the basis of the observed substitution effects, charge delocalization and availability were shown to be the critical descriptors determining co-catalytic activity. These descriptors can be used to rationalize activity trends for other classes of IL co-catalysts

Introduction of a Bifunctional Cation Affords Perovskite Solar Cells Stable at Temperatures Exceeding 80 degrees C

Perovskite solar cells (PSCs) with high efficiencies have been reported in recent years. Consequently, the main obstacle that hinders their commercialization is their poor thermal stability. Here, we describe the introduction of an A-site cation (2-choloroethylammonium) that affords an ABX(3) perovskite, which is stable at high temperatures (>80 degrees C) while achieving efficiencies > 19% in methylammonium lead iodide (MAPI)-based PSCs

Auto-passivation of crystal defects in hybrid imidazolium/methylammonium lead iodide films by fumigation with methylamine affords high efficiency perovskite solar cells

Hybrid perovskite solar cells have attracted tremendous interest in the photovoltaic community. Despite their high defect tolerance, reducing the trap density by material engineering and surface modification is still critical to further boost performance. Here, methylammonium lead(II) iodide perovskite has been doped with imidazolium iodide in high concentrations (10-30 mol%) to boost solar cell performance, by passivating defects. Fumigation with methylamine results in the deprotonation of the embedded imidazolium cations, generating imidazole and methylammonium cations. The resulting (neutral) imidazole is extruded from the 3-D perovskite crystal and distributes around the crystal leading to auto-passivation of crystal defects. The structure of the imidazolium-PbI3 salt intermediate (i.e. formed in the absence of the methylammonium cation) has been determined and the resulting perovskite film characterized. Employed in solar cells, a power conversion efficiency (PCE) up to 20.14% is demonstrated

A PEDOT:PSS‐Based Composite Hydrogel as a Versatile Electrode for Wearable Microneedle Sensing Platforms

Abstract Advances in biomarker detection have acclaimed a new era of biosensors that enable continuous monitoring of health status, device miniaturization, and wearability. This transition toward integrated, wearable biosensors has necessitated the co‐development of novel materials that can adequately support the operation of these devices. In this study, a novel type of electrode is presented that is suitable for use in wearable electrochemical biosensors. The electrode is constructed using a biocompatible composite hydrogel and takes the form of a hydrogel microneedle (HMN) patch. It is specifically designed for analyzing interstitial fluid. The HMN electrode is a combination of poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), a highly conductive polymer, and graphene oxide, incorporated into a crosslinked hydrogel network of methacrylated hyaluronic acid. To ensure the successful penetration of the skin, the fabrication process is carefully optimized to create sharp needles. To assess the performance of the HMN electrode, electrochemical tests are conducted using an ex vivo porcine skin model. Additionally, HMN electrode's suitability is demonstrated as the working electrode of a wearable electrochemical biosensor for in vivo measurement using a rat model. The findings highlight the advancement of the HMN electrode array as an alternative to solid microneedles, representing the next generation of polymeric electrodes

Supramolecular tuning of supported metal phthalocyanine catalysts for hydrogen peroxide electrosynthesis

Two-electron oxygen reduction offers a route to H2O2 that is potentially cost-effective and less energy-intensive than the industrial anthraquinone process. However, the catalytic performance of the highest performing prior heterogeneous electrocatalysts to H2O2 has lain well below the >300 mA cm−2 needed for capital efficiency. Herein, guided by computation, we present a supramolecular approach that utilizes oxygen functional groups in a carbon nanotube substrate that—when coupled with a cobalt phthalocyanine catalyst—improve cobalt phthalocyanine adsorption, preventing agglomeration; and that further generate an electron-deficient Co centre whose interaction with the key H2O2 intermediate is tuned towards optimality. The catalysts exhibit an overpotential of 280 mV at 300 mA cm−2 with turnover frequencies over 50 s−1 in a neutral medium, an order of magnitude higher activity compared with the highest performing prior H2O2 electrocatalysts. This performance is sustained for over 100 h of operation. [Figure not available: see fulltext.].N

Single-site decorated copper enables energy- and carbon-efficient CO2 methanation in acidic conditions

Abstract Renewable CH4 produced from electrocatalytic CO2 reduction is viewed as a sustainable and versatile energy carrier, compatible with existing infrastructure. However, conventional alkaline and neutral CO2-to-CH4 systems suffer CO2 loss to carbonates, and recovering the lost CO2 requires input energy exceeding the heating value of the produced CH4. Here we pursue CH4-selective electrocatalysis in acidic conditions via a coordination method, stabilizing free Cu ions by bonding Cu with multidentate donor sites. We find that hexadentate donor sites in ethylenediaminetetraacetic acid enable the chelation of Cu ions, regulating Cu cluster size and forming Cu-N/O single sites that achieve high CH4 selectivity in acidic conditions. We report a CH4 Faradaic efficiency of 71% (at 100 mA cm−2) with <3% loss in total input CO2 that results in an overall energy intensity (254 GJ/tonne CH4), half that of existing electroproduction routes