CO2/pH-responsive particles with built-in fluorescence read-out

yesA novel fluorescent monomer was synthesized to probe the state of CO2-responsive cross-linked polymeric particles. The fluorescent emission of this aminobromomaleimide-bearing monomer, being sensitive to protic environments, can provide information on the core hydrophilicity of the particles and therefore indicates the swollen state and size of the particles. The particles’ core, synthesized from DEAEMA (N,N-diethylaminoethyl methacrylate), is responsive to CO2 through protonation of the tertiary amines of DEAEMA. The response is reversible and the fluorescence emission can be recovered by simply bubbling nitrogen into the particle solution. Alternate purges of CO2 and N2 into the particles’ solution allow several ON/OFF fluorescence emission cycles and simultaneous particle swelling/shrinking cycles.British Petroleum Company (BP), Engineering and Physical Sciences Research Council (EPSRC

Platinum Nanoparticle-Based Microreactors as Support for Neuroblastoma Cells

Excitotoxicity is a common phenomenon in several neurological diseases, associated with an impaired clearance of synaptically released glutamate, which leads to an overactivation of postsynaptic glutamate receptors. This will, in turn, start an intracellular cascade of neurotoxic events, which include exacerbated production of reactive oxygen species and ammonia toxicity. We report the assembly of microreactors equipped with platinum nanoparticles as artificial enzymes and polymer terminating layers including poly(dopamine). The biological response to these microreactors is assessed in human neuroblastoma cell culture. The microreactors' function to deplete hydrogen peroxide (H2O2) and ammonia is confirmed. While the proliferation of the cells depends on the number of microreactors present, no inherent toxicity is found. Furthermore, the microreactors are able to ameliorate the effects of excitotoxicity in cell culture by scavenging H2O2 and ammonia, thus having the potential to provide a therapeutic approach for several neurological diseases in which excitotoxicity is observed

Ion channels boost axonal injury in multiple sclerosis

In neuroinflammatory diseases such as multiple sclerosis, ion channels may fan the embers of neurodegeneration. A new study shows that the cation channel TRPM4 (transient receptor potential melastatin 4) crucially contributes to axonal loss in an animal model of multiple sclerosis (pages 1805-1811)

Redox active polymers with phenothiazine moieties for nanoscale patterning via conductive scanning force microscopy

Redox active polymers with phenothiazine moieties have been synthesized by Atomic Transfer Radical Polymerization (ATRP). These novel polymers reveal bistable behaviour upon application of a bias potential above the oxidation threshold value. Using conductive Scanning Force Microscopy, two distinguishable conductivity levels were induced on a nanoscale level. These levels were related to a high conducting "On" and a low conducting "Off" state. The "On" state is generated by the oxidation of the phenothiazine side chains to form stable phenothiazine radical cations. The formation and stability of the radical sites was examined by cyclic voltammetry, electron spin resonance and optical spectroscopy. Polymers with phenothiazine moieties show the ability to retain their redox state for several hours and can therefore be used for nonvolatile organic memory devices. Furthermore, thin films made from the phenothiazine containing polymers show high mechanical nanowear stability

TRPM4 inhibition promotes angiogenesis after ischemic stroke

10.1007/s00424-013-1347-4Pflugers Archiv European Journal of Physiology4663563-576PFLA