WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Shape and Surface Modification Dependent Cellular Interactions of Gold Nanoparticles in a 3D Blood-Brain Supported Neurospheroid Model
    (Churchill Livingstone, 2025) Tomak, Aysel; Saglam-Metiner, Pelin; Coban, Reyhan; Oksel-Karakus, Ceyda; Yesil-Celiktas, Ozlem
    Recent investigations have begun to explore the cellular interactions of nanoparticles (NPs) in three-dimensional (3D) neuro-spheroid models of the blood-brain barrier (BBB), offering novel insights into NP transport across the barrier and their potential neurotoxic effects. Building on these findings, we investigated the effects of particle shape and surface modification on the transport dynamics and cellular interactions of gold NPs (AuNPs) using a multicellular 3D spheroid model of the BBB. AuNPs with two different morphologies, spherical and rod-like, were synthesized, modified with polyethylene glycol (PEG) and characterized in detail using Ultraviolet-Visible (UV-Vis) Spectroscopy, Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) techniques. A 3D neuro-spheroid model consisting of mouse brain endothelial cells (bEnd.3), motor neuron-like hybrid cells (NSC-34) and glial cells (C6) was employed to evaluate the BBB transport characteristics and cytotoxicity of bare and PEG-coated spherical and rod-shaped AuNPs. Our results indicated that 3D neurospheroid models can serve as orchestral platforms for studying cellular behaviour of NPs. PEGylation of NPs substantially reduced cytotoxic effects compared to bare particles. While spherical AuNPs showed limited translocation through the endothelial barrier, those that entered the spheroid were found to be distributed deeper within the interior. In contrast, rod-shaped particles exhibited a greater capacity to cross the BBB but tended to accumulate near the periphery without deeper penetration. These findings underscore the critical role of shape and surface chemistry in nanoparticle-mediated BBB transport and support the utility of 3D neuro-spheroid models in predicting nanoparticle behavior in brain tissue.
  • Article
    Citation - WoS: 32
    Citation - Scopus: 31
    Wien Effect in Interfacial Water Dissociation Through Proton-Permeable Graphene Electrodes
    (Nature Research, 2022) Cai, Junhao; Griffin, Eoin; Guarochico-Moreira, Victor H.; Barry, D.; Xin, B.; Yağmurcukardeş, Mehmet; Zhang, Sheng; Geim, Andre K.; Peeters, François M.; Lozada-Hidalgo, Marcelo
    Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 107 V m−1, sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H2O ⇆ H+ + OH−) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 108 V m−1. The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager’s theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport.
  • Conference Object
    Citation - Scopus: 1
    Range Identification for Nonlinear Parameterizable Paracatadioptric Systems
    (Institute of Electrical and Electronics Engineers Inc., 2009) Nath, Nitendra; Dawson, Darren M.; Tatlıcıoğlu, Enver
    In this paper, a new range identification technique for a calibrated paracatadioptric system mounted on a moving platform is developed to recover the range information and the three-dimensional (3D) Euclidean coordinates of a static object feature. The position of the moving platform is assumed to be measurable. To identify the unknown range, first a function of the projected pixel coordinates is related to the unknown 3D Euclidean coordinates of an object feature. This function is nonlinearly parameterized (i.e., the unknown parameters appear nonlinearly in the parameterized model). An adaptive estimator based on a min-max algorithm is then designed to estimate the unknown 3D Euclidean coordinates of an object feature relative to a fixed reference frame which facilitates the identification of range. A Lyapunov-type stability analysis is used to show that the developed estimator provides an estimation of the unknown parameters within a desired precision.