Neuroactivity of detonation nanodiamonds: dose-dependent changes in transporter-mediated uptake and ambient level of excitatory/inhibitory neurotransmitters in brain nerve terminals.

Natalia Pozdnyakova,Artem Pastukhov,Tatiana Borisova,Arsenii Borysov,Maxim Galkin,Marina Dudarenko

doi:10.1186/s12951-016-0176-y

Abstract

BackgroundNanodiamonds are one of the most perspective nano-sized particles with superb physical and chemical properties, which are mainly composed of carbon sp3 structures in the core with sp2 and disorder/defect carbons on the surface. The research team recently demonstrated neuromodulatory properties of carbon nanodots with other than nanodiamonds hybridization types, i.e., sp2 hybridized graphene islands and diamond-like sp3 hybridized elements.ResultsIn this study, neuroactive properties of uncoated nanodiamonds produced by detonation synthesis were assessed basing on their effects on transporter-mediated uptake and the ambient level of excitatory and inhibitory neurotransmitters, glutamate and γ-aminobutyric acid (GABA), in isolated rat brain nerve terminals. It was shown that nanodiamonds in a dose-dependent manner attenuated the initial velocity of Na+-dependent transporter-mediated uptake and accumulation of l-[14C]glutamate and [3H]GABA by nerve terminals and increased the ambient level of these neurotransmitters. Also, nanodiamonds caused a weak reduction in acidification of synaptic vesicles and depolarization of the plasma membrane of nerve terminals.ConclusionsTherefore, despite different types of hybridization in nanodiamonds and carbon dots, they exhibit very similar effects on glutamate and GABA transport in nerve terminals and this common feature of both nanoparticles is presumably associated with their nanoscale size. Observed neuroactive properties of pure nanodiamonds can be used in neurotheranostics for simultaneous labeling/visualization of nerve terminals and modulation of key processes of glutamate- and GABAergic neurotransmission. In comparison with carbon dots, wider medical application involving hypo/hyperthermia, external magnetic fields, and radiolabel techniques can be perspective for nanodiamonds.

Highlights

Nanodiamonds are one of the most perspective nano-sized particles with superb physical and chemical properties, which are mainly composed of carbon sp3 structures in the core with sp2 and disorder/defect carbons on the surface
The present study focused on the estimation of the effects of pure uncoated NDs produced by detonation synthesis on the key characteristics of glutamatergic and GABAergic neurotransmission in isolated rat brain nerve terminals, thereby uncovering their possible neuroactive properties
They retain all characteristics of intact nerve terminals, that is, the ability to maintain membrane potential, accomplish uptake and transportermediated release of glutamate, exocytosis, endocytosis, etc

Summary

Introduction

Nanodiamonds are one of the most perspective nano-sized particles with superb physical and chemical properties, which are mainly composed of carbon sp structures in the core with sp and disorder/defect carbons on the surface. Nanodiamonds (NDs) are one of the most perspective nano-sized particles due to their unique physical and chemical properties, e.g., excellent mechanical and optical properties, high surface areas and tunable surface structures [4,5,6]. They are mainly composed of carbon sp structures in the core, with sp and disorder/defect carbons on the surface [6].

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