Nano-Ag inhibiting action potential independent glutamatergic synaptic transmission but increasing excitability in rat CA1 pyramidal neurons

The aim of this study was to investigate the actions of silver nanoparticles (nano-Ag) on glutamatergic synaptic transmission and excitability in hippocampal CA1 pyramidal neurons with whole cell patch technique. The amplitude of miniature excitatory postsynaptic currents (mEPSCs) was inhibited by silver nano-particles (nano-Ag) (10(-5) g/ml and 10(-4) g/ml), but the amplitude and frequency of spontaneous excitatory postsynaptic currents (sEPSCs) were increased by nano-Ag treatment (10(-5) g/ml and 10(-4) g/ml). Furthermore, nano-Ag (10(-5) g/ml and 10(-4) g/ml) increased the spontaneous network activity. These results provide further insights into the underlying mechanisms responsible for the effects of nano-Ag on central nervous system (CNS).Peer reviewedFinal Accepted Versio

Measurement and multilayer model of cooling of gold nanoparticles: Transient thermoreflectance experiments and multilayer analytical modeling

We derive an analytical model of diffusive thermal transport in multilayer structures of spherical symmetry and apply it to transient thermoreflectance measurements of gold nanoparticles embedded in a polymer matrix. This multilayer approach significantly improves the quantitative measurement of material thermal properties, in comparison with single-layer methods. The model adapts the typical planar transfer matrix model to a spherical geometry, and we apply it to transient thermoreflectance (TTR) experiments on gold nanoparticles embedded in a polymer matrix, to published TTR data for aqueous platinum nanoparticles, and also to example systems of aqueous gold and platinum nanoparticles. We measure a thermal boundary conductance value of 410MW/m2K role= presentation style= display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e410MW/m2K410MW/m2K at the nanoparticle gold/polymer interface. The sensitivity of the TTR signal to system thermal properties is predicted as a function of the particle/matrix thermal boundary resistance (TBR), and we discuss the differentiation of TBR and capping layer effects on a TTR signal

A review of nanoparticle functionality and toxicity on the central nervous system

Original article can be found at : http://rsif.royalsocietypublishing.org/ Copyright The Royal Society [Full text of this article is not available in the UHRA]Although nanoparticles have tremendous potential for a host of applications, their adverse effects on living cells have raised serious concerns recently for their use in the healthcare and consumer sectors. As regards the central nervous system (CNS), research data on nanoparticle interaction with neurons has provided evidence of both negative and positive effects. Maximal application dosage of nanoparticles in materials to provide applications such as antibacterial and antiviral functions is approximately 0.1-1.0 wt%. This concentration can be converted into a liquid phase release rate (leaching rate) depending upon the host or base materials used. For example, nanoparticulate silver (Ag) or copper oxide (CuO)-filled epoxy resin demonstrates much reduced release of the metal ions (Ag+ or Cu2+) into their surrounding environment unless they are mechanically removed or aggravated. Subsequent to leaching effects and entry into living systems, nanoparticles can also cross through many other barriers, such as skin and the blood-brain barrier (BBB), and may also reach bodily organs. In such cases, their concentration or dosage in body fluids is considered to be well below the maximum drug toxicity test limit (10(-5) g ml(-1)) as determined in artificial cerebrospinal solution. As this is a rapidly evolving area and the use of such materials will continue to mature, so will their exposure to members of society. Hence, neurologists have equal interests in nanoparticle effects (positive functionality and negative toxicity) on human neuronal cells within the CNS, where the current research in this field will be highlighted and reviewed.Peer reviewe