Plastic substrates made of polystyrene (PS) and Zeonor 1060R were treated with oxygen plasma to introduce polar groups (e.g., carbonyl and carboxylic acid) at the surface that render these materials hydrophilic and promote patterned adhesion of HeLa cells. Resultant surfaces were characterized using contact angle goniometry, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) to monitor changes in wettability, nanoscale topography, and chemical composition. Biocompatibility of the plastic surfaces was verified through fluorescence microscopy using three fluorophores, Alexa Fluor 488 conjugated to Annexin V, Hoechst 33258, and propidium iodide, indicating cells that undergo apoptosis and necrosis, respectively. The best cell growth was observed on PS treated at 5 W/sccm, for which the viability of adhering HeLa cells exceeded 90%. Patterning was accomplished using an elastomeric microcapillary system ( μCS) made of poly(dimethylsiloxane) (PDMS) that consisted of a set of parallel channels to align cells in linear fashion. Densely populated bands were obtained on substrates of both plastic materials when the culture medium contained >2 Â 10 5 cells/mL.

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Controlled payload release is one of the key elements in the creation of a reliable drug delivery system. We report the discovery of a drug delivery vessel able to transport chemotherapeutic agents to target cancer cells and selectively trigger their release using the electrochemical activity of a ferrocene-modified phospholipid. Supported by in vitro assays, the competitive advantages of this discovery are (i) the simple one step scalability of the synthetic process, (ii) the stable encapsulation of toxic drugs (doxorubicin) during transport, and (iii) the selective redox triggering of the liposomes to harness their cytotoxic payload at the cancer site. Specifically, the redox-modified giant unilamellar vesicle and liposomes were characterized using advanced methods such as scanning electrochemical microscopy (SECM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and fluorescent imaging.

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The trade-off between energy density and power capabilities is a challenge for Li-ion battery design as it highly depends on the complex porous structures that holds the liquid electrolyte. Specifically, mass-transport limitations lead to large concentration gradients in the solution-phase and subsequently to crippling overpotentials. The direct study of these solution-phase concentration profiles in Li-ion battery positive electrodes has been elusive, in part because they are shielded by an opaque and paramagnetic matrix. Herein we present a new methodology employing synchrotron hard X-ray fluorescence to observe the concentration gradient formation within Li-ion battery electrodes in operando. This methodology is substantiated with data collected on a model LiFePO 4 /Li cell using a 1 M LiAsF 6 in 1:1 ethylene carbonate/dimethyl carbonate (EC/DMC) electrolyte under galvanostatic and intermittent charge profiles. As such, the technique holds great promise for optimization of new composite electrodes and for numerical model validation.

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With the current climate crisis having no end in sight, communities worldwide are depending on new battery technology to store energy from intermittent sources of energy such as wind and solar. Li-ion batteries (LIBs) have presented themselves as a worthy candidate for the task given their high capacity for charge as well as their durability in terms of cycle life. LIB models have been developed extensively for the purpose of understanding current behaviour and predicting future performance. A limiting factor in LIBs is the rate at which they can be (dis)charged which can be extensively hindered by the formation of a concentration gradient of Li+ within the positive and negative electrodes. Although the models that exist can predict what these gradients should be within the electrodes, there has, as of yet, been no experimental data representing the concentration gradient formation within the electrode pores. Using X-ray fluorescence (XRF) in conjunction with a synchrotron light source allows the spatially resolved observation of the Li+ concentration profile. This work can validate the predictive power of established P2D models in order to improve their accuracy in addition to serving as a screening technique for new composite positive electrodes. Figure 1

Lead and Arsenic are two of the most toxic common water contaminants. We report on a new type of portable and sustainable device designed for arsenic and lead removal from...