12 research outputs found
Fabrication platform for 3D microelectrode arrays based on support structures for interfacing with in vitro 3D neuronal networks
No full textA 3D-printed pillar-based microelectrode array for parallel recording of cortical spheroids
No full textDevelopment of the micropatterned 3D hydrogel-neuron model based on soft lithography for the study of 3D neural network chip using microelectrode array
No full text학위논문(석사) - 한국과학기술원 : 바이오및뇌공학과, 2021.2,[vii, 108 p. :]우리 뇌에는 다양한 구조적 연결도 패턴의 신경 회로가 존재하고 각 회로마다의 뇌의 기능에 중요한 역할을 하는 고유한 기능을 가지고 있다. 뇌의 기능을 이해하기 위해선 신경 회로의 연결도와 기능에 대한 연구가 필요하다. 체외 신경세포 모델은 한가지 접근법으로서, 신경세포의 패터닝을 통해 해당 모델이 가지고 있는 신경생리학적 특성에 대한 분석이 이루어지고 있다. 하지만 3차원 세포 모델의 중요성이 대두되고 있는 현재, 이러한 연구는 대부분 2차원 모델에 대해서 행해졌었다. 본 연구에서는 3차원 환경에 대한 구조적 연결도와 기능적 활성도를 분석할 수 있는 신경세포 실험 모델을 제작하였다. 세포외기질 기반의 하이드로겔을 이용해 신경세포의 3차원 모델을 구성시키고 MIMIC 기술을 이용해 미세패턴을 지닌 3차원 하이드로겔-신경세포 모델을 제작하였다. 해당 모델은 신경 신호 측정을 위해 미세전극칩 위에 제작되어 3차원 신경세포 모델의 전기 신호를 측정하였다. 미세패턴의 구조 유지를 위해 하이드로겔-신경세포 인터페이스를 조사하였다. 해당 미세패턴을 지닌 신경세포 모델을 이용해 3차원 모델에 대한 구조적 연결도와 기능적 활성도에 대한 관계를 연구하는데 사용될 것으로 기대한다.한국과학기술원 :바이오및뇌공학과
Construction of 3D neural network signal recording interface using cell clustering on microelectrode array for analysis of 3D network dynamics
No full textA 3D neuronal network read-out interface with high recording performance using a neuronal cluster patterning on a microelectrode array
No full textIn recent years, in vitro three-dimensional (3D) neuronal network models utilizing extracellular matrices have been advancing. To understand the network activity from these models, attempts have been made to measure activity in multiple regions simultaneously using a microelectrode array (MEA). Although there hve been many attempts to measure the activity of 3D networks using 2-dimensional (2D) MEAs, the physical coupling between the 3D network and the microelectrodes was not stable and needed to be improved. In this study, we proposed a neuronal cluster interface that improves the active channel ratio of commercial 2D MEAs, enabling reliable measurement of 3D network activity. To achieve this, neuronal clusters, which consist of a small number of neurons, were patterned on microelectrodes and used as mediators to transmit the signal between the 3D network and the microelectrodes. We confirmed that the patterned neuronal clusters enhanced the active channel ratio and SNR(signal-to-noise-ratio) about 3D network recording and stimulation for a month. Our interface was able to functionally connect with 3D networks and measure the 3D network activity without significant alternation of activity characteristics. Finally, we demonstrated that our interface can be used to analyze the differences in the dynamics of 3D and 2D networks and to construct the 3D clustered network. This method is expected to be useful for studying the functional activity of various 3D neuronal network models, offering broad applications for the use of these models.
CHARACTERIZATION OF THE WHOLE NEURAL NETWORK SIGNAL READOUT PLATFORM FROM A 3D NEURONAL NETWORK USING THE CELL PATTERNING ON A MICROELECTRODE ARRAY
No full textDevelopment of the Micro-Patterned 3D Neuronal-Hydrogel Model Using Soft-Lithography for Study a 3D Neural Network on a Microelectrode Array
No full textIn vitro patterned neuronal models have been studied as one of the strategies to investigate the relationship between structural connectivity and functional activity of neural network. Despite the importance of three-dimensional (3D) cell models, most of these studies have been performed on two-dimensional models. In this study, we present a technique to construct the micro-pattern to 3D neuronal-hydrogel model using a micromolding in capillaries (MIMIC) technique on microelectrode array (MEA). Our technique was suitable to prevent the deformation of micro-patterned collagen model against the neuronal contracted tension during the network formation. The relationship between the growth directions of glial cells and micro-pattern direction was investigated. Lastly, we confirmed that our 3D model had synchronized activity among neurons in 3D. This model is expected to be used as a tool to study the relationship between structural connectivity and functional activity in the 3D environment
Enhancement of Thermoplasmonic Neural Modulation Using a Gold Nanorod-Immobilized Polydopamine Film
No full textPhotothermal
neural activity inhibition has emerged as a minimally
invasive neuromodulation technology with submillimeter precision.
One of the techniques involves the utilization of plasmonic gold nanoparticles
(AuNPs) to modulate neural activity by photothermal effects (“thermoplasmonics”).
A surface modification technique is often required to integrate AuNPs
onto the neural interface. Here, polydopamine (pDA), a multifunctional
adhesive polymer with a wide light absorption spectrum, is introduced
both as a primer layer for the immobilization of gold nanorods (GNRs)
on the neural interface and as an additional photothermal agent by
absorbing near-infrared red (NIR) lights for more efficient photothermal
effects. First, the optical and photothermal properties of pDA as
well as the characteristics of GNRs attached onto the pDA film are
investigated for the optimized photothermal neural interface. Due
to the covalent bonding between GNR surfaces and pDA, GNRs immobilized
on pDA showed strong attachment onto the surface, yielding a more
stable photothermal platform. Lastly, when photothermal neural stimulation
was applied to the primary rat hippocampal neurons, the substrate
with GNRs immobilized on the pDA film allowed more laser power-efficient
photothermal neuromodulation as well as photothermal cell death. This
study suggests the feasibility of using pDA as a surface modification
material for developing a photothermal platform for the inhibition
of neural activities
Hybrid biofabrication of multilayered 3D neuronal networks with structural and functional interlayer connectivity
No full textIn vitro implementation of three-dimensional (3D) neuronal models that mimic the brain's structure, such as the modular organization, requires technologies that can precisely fabricate structural organization and functional connectivity. Conventional microextrusion bioprinting provides spatial control to impart structural features to neural tissue models but requires hydrogels of higher viscosity that compromise cellular activity and restrict neurite extension and network formation. In this study, we integrated a micromesh-based bioprinting platform with neuronal analysis techniques to fabricate and analyze the heterogeneous and multilayered modular neuronal constructs using fibrin with high printing resolution and cell viability. The platform was integrated with microelectrode arrays and calcium imaging to simultaneously measure neuronal activity at different layers within the modular organization. We found that each module layer exhibited spontaneous and synchronized activity with synapse formation via neurites connecting module layers. This functional connectivity was further validated by the propagation of electrical stimulation from the bottom layer to the top layer. This study provides a promising foundation for studying structure-function relationships in 3D neuronal networks and developing more physiologically relevant in vitro brain models.
Label-free monitoring of 3D cortical neuronal growth in vitro using optical diffraction tomography
No full textThe highly complex central nervous systems of mammals are often studied using three-dimensional (3D) in vitro primary neuronal cultures. A coupled confocal microscopy and immunofluorescence labeling are widely utilized for visualizing the 3D structures of neurons. However, this requires fixation of the neurons and is not suitable for monitoring an identical sample at multiple time points. Thus, we propose a label-free monitoring method for 3D neuronal growth based on refractive index tomograms obtained by optical diffraction tomography. The 3D morphology of the neurons was clearly visualized, and the developmental processes of neurite outgrowth in 3D spaces were analyzed for individual neurons.
