Micro-nanotechnology platforms for monitoring neural cell secretion and culturing neurospheroids
Date
2022-05
Authors
Yang, Renyuan
Major Professor
Advisor
Que, Long
Jiles, David
Sakaguchi, Donald
Fu, Houqiang
Song, Jiming
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Abstract
As the aging population becomes a growing global trend, more and more people are afflicted by neurodegenerative disorders (NDD). It has been found that transcranial magnetic stimulation (TMS) has therapeutic effect on the NDD. The TMS has been approved by the FDA for the clinical treatment for the depression. However, the molecular-level principle underlying the TMS effect is not clear so far. Glial cell derived neurotrophic factors (GDNF) is considered to play an important role in protecting and restoring dopaminergic neurons and motor neurons, and thus has great value to develop treatment on Parkinson’s disease. Detection of GDNF level becomes increasing important for studies on the GDNF. Recently, brain-on-a-chip platforms has drawn tremendous attention from the research community, due to its merits: low cost, high efficiency, high throughput, better mimicking in vivo environment, potential to replace animal models. The brain-on-a-chip platforms can provide an excellent in vitro model to study the neurogenesis, NDD pathology, drug screening and so on. Understanding the behaviors of neural cells and establishing in vitro brain models are critically important for exploring potential treatments.
My research work consists of two parts: (1) an optical thin-film biosensor has been developed to study the TMS effect on the secretion of GDNF from N27 cells. The sensor consists of nanopore thin film, prepared by E-beam evaporation, anodic oxidation and sputtering process. The porous surface is functionalized with GDNF antibodies. The detection principle is based on light interference as the thin-film biosensor acts like Fabry-Pérot interferometer. GDNF molecule binding on the sensor surface causes effective thickness or refractive index change, giving rise to interference pattern change. This type of nanosensor offers significantly improved limit of detection for GDNF and good specificity. We found that the TMS can promote GDNF secretion from N27 cells, which may constitute a plausible reason to explain the TMS therapeutic effect on the NDD. (2) A microfluidic platform has been developed to culture and analyze in vitro brain models on chip. COMSOL Multiphysics is used to simulate the working principle of the microfluidic device. The simulation result can help design the microfluidic chip, which is then fabricated by soft lithography and reflow process. The microchambers for cell culturing are 360 µm in diameter and 150-200 µm in depth. Rat adult hippocampal progenitor cells (AHPCs) are used as cell model. The cells are seeded into the chip and cultured for 12 days. The daily images of the cells on chip show that the cells can live, proliferate, form cell clusters and eventually develop into neurospheroids. Biomarkers are used to evaluate cell viability, proliferation and neural differentiation in the neurospheroids. The cell viability is found to be high in the chip, exhibiting a good device biocompatibility. The cells keep a constant proliferation rate throughout 12 days. The size of the neurospheroids keeps growing due to cell proliferation and aggregation. The differentiation results reveal that the AHPCs can differentiate into astrocytes, oligodendrocytes, immature and mature neurons. Besides, the microfluidic chip can support on-chip high-resolution confocal fluorescence imaging, a powerful tool for advanced cell analysis. So, our microfluidic platform allows on-chip study of cell viability, proliferation, and neuronal differentiation. Our work shows the feasibility to culture AHPC neurospheroid as a suitable in vitro brain model on chip.
Series Number
Journal Issue
Is Version Of
Versions
Series
Academic or Administrative Unit
Type
dissertation