Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1832588 (PSS)
 2,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this paper the easy and reliable preparation of precise micropatterns on PDMS surfaces is described and the growth of HEK 293 cells on those patterns during culture over several days is examined. The first patterning approach described is based on soft-lithography and polyelectrolyte multilayer deposition. Two different soft-lithographic techniques are employed for creating surface patterns of PAH, PSS, untreated and oxidized PDMS. The growth behavior of HEK 293 cells is investigated on all the dual combinations of the four surfaces, and decreasing preference of the cells for the surfaces in the order PAH (-NH2)>ox-PDMS (-OH)>>PSS (-SO3-)>PDMS (-CH3) is revealed. As the second patterning approach a method is introduced, which allows the deposition of gel droplets in a microarray format utilizing differences in the surface wettability. This concept is new and expected to be very useful for various applications. Finally, a speculative explanation for the different cell spreading behavior is provided considering the interplay between individual cell-surface interactions and a permanent cell tractional force.
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PMID:Micropatterned surfaces of PDMS as growth templates for HEK 293 cells. 1750 89

Conventional alginate/poly-L-ornithine (AP) membranes used to immunoisolate foreign tissue transplants fail in long-term transplantations of immortal cell lines. We have developed a novel layer-by-layer (LbL) membrane using polystyrene sulfonate and polyallylamine hydrochloride (PSS/PAH) on top of the coherent AP membrane. Assembly of the LbL membrane was followed by electrophoresis, and the surface morphologies and structure were characterized and examined by cryo-scanning electron microscope and transmission electron microscopy. Unlike the standard AP membrane, the LbL membrane withstood the internal pressure generated by continuous cell proliferation of microencapsulated HEK-293 and Min-6 cells. The new membrane did not affect insulin secretion or diffusion by Min-6 cells.
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PMID:Assembly of multilayer PSS/PAH membrane on coherent alginate/PLO microcapsule for long-term graft transplantation. 1828 25

Polyelectrolyte films of anionic poly(sodium 4-styrenesulphonate) (PSS) and cationic poly (allylamine hydrochloride) (PAH) were constructed using layer-by-layer assembly. The authors examined the cytocompatibility of these films for future use in nanobiotechnology applications. Cell lines HEK-293 and 3T3-L1 were cultured on these films and the initial attachment, adhesion, proliferation and cytotoxicity of the cells were measured using a propidium iodide assay. The morphology and spread of the cells were measured by phase-contrast microscopy. The actin cytoskeleton was observed using fluorescent microscopy. Neither the PAH-terminated nor the PSS-terminated polyelectrolyte films were cytotoxic. The PAH-terminated polyelectrolyte films improved the initial attachment and subsequent adhesion of the cells, in addition to enhancing the production of extracellular matrix and the modelling of the actin filaments. The PSS-terminated film enhanced the proliferation of the cells compared to the PAH-terminated film. That was despite the cell cycle, the spreading or the cytotoxicity of both cell types being similar for either the PSS-terminated surfaces or the PAH-terminated surfaces. Cell behaviour can be modulated by the final surface charge of the polyelectrolyte film and the results are useful in guiding the choice of substrates and/or coatings for potential biomedical applications (e.g. implants) as well as cell biology research.
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PMID:Terminating polyelectrolyte in multilayer films influences growth and morphology of adhering cells. 2072 74

Transmembrane proteins represent a major target for modulating cell activity, both in terms of therapeutics drugs and for pathogen interactions. Work on screening such therapeutics or identifying toxins has been severely limited by the lack of available methods that would give high content information on functionality (ideally multimodal) and that are suitable for high-throughput. Here, we have demonstrated a platform that is capable of multimodal (optical and electronic) screening of ligand gated ion-channel activity in human-derived membranes. The TREK-1 ion-channel was expressed within supported lipid bilayers, formed via vesicle fusion of blebs obtained from the HEK cell line overexpressing TREK-1. The resulting reconstituted native membranes were confirmed via fluorescence recovery after photobleaching to form mobile bilayers on top of films of the polymeric electroactive transducer poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS). PEDOT:PSS electrodes were then used for quantitative electrochemical impedance spectroscopy measurements of ligand-mediated TREK-1 interactions with two compounds, spadin and arachidonic acid, known to suppress and activate TREK-1 channels, respectively. PEDOT:PSS-based organic electrochemical transistors were then used for combined optical and electronic measurements of TREK-1 functionality. The technology demonstrated here is highly promising for future high-throughput screening of transmembrane protein modulators owing to the robust nature of the membrane integrated device and the highly quantitative electrical signals obtained. This is in contrast with live-cell-based electrophysiology assays (e.g., patch clamp) which compare poorly in terms of cost, usability, and compatibility with optical transduction.
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PMID:Optical and Electronic Ion Channel Monitoring from Native Human Membranes. 3246 90