Research Project: Kalp Hücre Uyarımı için Yakın Kızılötesine Duyarlı, Kuantum Nokta Tabanlı ve Hidrojel Entegre Edilmiş Kapasitif Optoelektronik Biyoa rayüzler
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Contributors
Funders
ID
TB.00705
Authors
Nizamoğlu, Sedat
Faculty Member
Publications
Capacitive and efficient near-infrared stimulation of neurons via an ultrathin AgBiS2 nanocrystal layer
(American Chemical Society, 2024) Balamur, Rıdvan; Hasanreisoğlu, Murat; Kaleli, Humeyra Nur; Karatüm, Onuralp; Nizamoğlu, Sedat; Önal, Asım; Pehlivan, Çiğdem; Şahin, Afsun; Oh, Jae Taek; Wang, Yongjie; Konstantatos, Gerasimos; Department of Electrical and Electronics Engineering; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; KUTTAM (Koç University Research Center for Translational Medicine); School of Medicine; Yes; College of Engineering; GRADUATE SCHOOL OF HEALTH SCIENCES; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Research Center; SCHOOL OF MEDICINE
Colloidal nanocrystals (NCs) exhibit significant potential for photovoltaic bioelectronic interfaces because of their solution processability, tunable energy levels, and inorganic nature, lending them chemical stability. Silver bismuth sulfide (AgBiS2) NCs, free from toxic heavy-metal elements (e.g., Cd, Hg, and Pb), particularly offer an exceptional absorption coefficient exceeding 10(5) cm(-1) in the near-infrared (NIR), surpassing many of their inorganic counterparts. Here, we integrated an ultrathin (24 nm) AgBiS2 NC layer into a water-stable photovoltaic bioelectronic device architecture that showed a high capacitive photocurrent of 2.3 mAcm(-2) in artificial cerebrospinal fluid (aCSF) and ionic charges over 10 mu Ccm(-2) at a low NIR intensity of 0.5 mWmm(-2). The device without encapsulation showed a halftime of 12.5 years under passive accelerated aging test and did not show any toxicity on neurons. Furthermore, patch-clamp electrophysiology on primary hippocampal neurons under whole-cell configuration revealed that the device elicited neuron firing at intensity levels more than an order of magnitude below the established ocular safety limits. These findings point to the potential of AgBiS2 NCs for photovoltaic retinal prostheses.
Optical neuromodulation at all scales: from nanomaterials to wireless optoelectronics and integrated systems
(Royal Society of Chemistry (RSC), 2023) Karatüm, Onuralp; Nizamoğlu, Sedat; Önal, Asım; Gwak, Min-Jun; Hyun, Junghun; Koirala, Gyan Raj; Kim, Tae-Il; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Yes; College of Engineering; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
Light-based neuromodulation systems offer exceptional spatiotemporal resolution combined with the elimination of physical tether to communicate with neurons. Currently, optical neuromodulation systems ranging from the nano to the centimeter scale enable neural activity control from the single cell to the organ level in retina, heart, spinal cord, and brain, facilitating a wide range of experiments in intact and freely moving animals in different contexts, such as during social interactions and behavioral tasks. Nanotransducers (e.g., metallic nanoparticles, silicon nanowires, and polymeric nanoparticles) and microfabricated photodiodes convert light to electrical, thermal, and mechanical stimuli that can allow remote and non-contact stimulation of neurons. Moreover, integrated devices composed of nano and microscale optoelectronic components comprise fully implantable and wirelessly powered smart optoelectronic systems that exhibit multimodal and closed-loop operation. In this review, we first discuss the material platforms, stimulation mechanisms, and applications of passive systems, i.e., nanotransducers and microphotodiodes. Then, we review the use of organic and inorganic light-emitting diodes for optogenetics and implantable wireless optoelectronic systems that enable closed-loop optogenetic neuromodulation through the use of light-emitting diodes, wireless power transfer circuits, and feedback loops. Exploration of materials and mechanisms together with the presented applications from both research and clinical perspectives in this review provides a comprehensive understanding of the optical neuromodulation field with its advantages and challenges to build superior systems in the future.
MNO2 nanoflower integrated optoelectronic biointerfaces for photostimulation of neurons
(Wiley, 2023) Kaleli, Humeyra Nur; Önal, Asım; Nizamoğlu, Sedat; Balamur, Rıdvan; Kaya, Lokman; Hasanreisoğlu, Murat; Karatüm, Onuralp; Vanalakar, Sharadrao Anandrao; KUTTAM (Koç University Research Center for Translational Medicine); Department of Electrical and Electronics Engineering; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; School of Medicine; Yes; College of Engineering; GRADUATE SCHOOL OF HEALTH SCIENCES; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING; Research Center; SCHOOL OF MEDICINE
Optoelectronic biointerfaces have gained significant interest for wireless and electrical control of neurons. Three-dimentional (3D) pseudocapacitive nanomaterials with large surface areas and interconnected porous structures have great potential for optoelectronic biointerfaces that can fulfill the requirement of high electrode-electrolyte capacitance to effectively transduce light into stimulating ionic currents. In this study, the integration of 3D manganese dioxide (MnO2) nanoflowers into flexible optoelectronic biointerfaces for safe and efficient photostimulation of neurons is demonstrated. MnO2 nanoflowers are grown via chemical bath deposition on the return electrode, which has a MnO2 seed layer deposited via cyclic voltammetry. They facilitate a high interfacial capacitance (larger than 10 mF cm(-2)) and photogenerated charge density (over 20 & mu;C cm(-2)) under low light intensity (1 mW mm(-2)). MnO2 nanoflowers induce safe capacitive currents with reversible Faradaic reactions and do not cause any toxicity on hippocampal neurons in vitro, making them a promising material for biointerfacing with electrogenic cells. Patch-clamp electrophysiology is recorded in the whole-cell configuration of hippocampal neurons, and the optoelectronic biointerfaces trigger repetitive and rapid firing of action potentials in response to light pulse trains. This study points out the potential of electrochemically-deposited 3D pseudocapacitive nanomaterials as a robust building block for optoelectronic control of neurons.
