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Biology subjects

Ersoy, F.

Publications and source records attributed to Ersoy, F..

5 recordsLinked to original sources

A scalable mesh microelectrode array platform for longitudinal electrophysiology in neural spheroids

Electrophysiological interfacing remains difficult in three-dimensional in vitro models, when using planar microelectrode arrays or optical methods. This challenge limits experimental progress using such models, despite their promise of better physiological relevance than monolayer cell culture. Mesh MEAs which can integrate conformally on or even within tissue offer a possible solution but are not yet widely accessible. Here, we present a mesh MEA device, designed as a simple, manufacturable platform for spheroid electrophysiology. In neural spheroids, the device enabled longitudinal electrophysiological recordings and pharmacological modulation of spontaneous electrical activity. On native polyimide meshes, spheroids maintained their shape while cells enveloped the mesh, embedding electrodes to a depth of 100 {micro}m after 2 weeks. In contrast, laminin biofunctionalization of the mesh promoted outgrowth and migration of cells. This device and associated methods should be adaptable to organoids, ex vivo tissue, or bioengineered in vitro models.

neuroscience↗

Electrophysiological profiling of hiPSC-derived neurospheres using a novel NeuroMPS with integrated electrodes

Despite advances in microphysiological systems, in vitro platforms for neuronal models remain limited by insufficient electrophysiological resolution, poor structural compatibility with 3D tissue architecture, and an inability to capture functional network dynamics alongside morphological and metabolic readouts. Here, we develop a neuromicrophysiological system (NeuroMPS) that pairs human iPSC-derived neurospheres, comprising neurons and glial cells, with tailored microelectrode arrays (MEAs) for non-invasive, high-resolution monitoring of neuronal network dynamics and functional maturation in vitro. The NeuroMPS combines a custom MEA with capped electrodes optimized for neurite-level signal detection and a glass microwell module that provides structural confinement and optical compatibility for imaging. Importantly, this configuration enables stable, longitudinal electrophysiological recordings from 3D neural constructs while supporting multimodal analyses. Following exposure to pharmacological modulators (PTX, TTX, bicuculline, CNQX, and 4-AP) and the neurotoxin rotenone, NeuroMPS detects alterations in network activity within minutes, even at the lowest concentrations tested, whereas morphological and metabolic changes emerge only at higher doses and later time points. This work provides a physiologically relevant, scalable, non-invasive platform that integrates high-sensitivity electrophysiological readouts with morphological and metabolic profiling to enable early prediction of compound-induced effects in human iPSC-derived 3D neural networks, with applications in neuropharmacology, neurotoxicology, and disease modeling.

bioengineering↗

Cancer-mediated Axonal Guidance of Sensory Neurons in a Microelectrode-based Innervation MPS

Despite recent advances in the field of microphysiological systems (MPS), availability of models capable of mimicking the interactions between the nervous system and innervated tissues is still limited. This represents a significant challenge in identifying the underlying processes of various pathological conditions, including neuropathic, cardiovascular and metabolic disorders. In this study, we introduce a compartmentalized 3D coculture system that enables physiologically relevant tissue innervation while recording neuronal excitability. By integrating custom microelectrode arrays into tailored glass chips microfabricated via selective laser-etching, we developed an entirely novel class of innervation MPSs (INV-MPS). This INV-MPS allows for manipulation, visualization, and electrophysiological analysis of individual axons innervating complex 3D tissues. Here, we focused on sensory innervation of 3D tumor tissue as a model case study since cancer-induced pain represents a major unmet medical need. The system was compared with existing nociception models and successfully replicated axonal chemoattraction mediated by nerve growth factor (NGF). Remarkably, in the absence of NGF, 3D cancer spheroids cocultured in the adjacent compartment induced sensory neurons to consistently cross the separating barrier and establish fine innervation. Moreover, we observed that crossing sensory fibers could be chemically excited by distal application of known pain-inducing agonists only when cocultured with cancer cells. To our knowledge, this is the first system showcasing morphological and electrophysiological analysis of 3D-innervated tumor tissue in vitro, paving the way for a plethora of studies into innervation-related diseases and improving our understanding of underlying pathophysiology. Significance StatementMPSs integrating innervated tissues are crucial as alternatives to animal models and to enhance the translation of non-clinical research to humans, as nerve fibers play a pivotal role in many organs. To address this need, we developed the INV-MPS, enabling parallelized electro-physiological recording from 3D cocultures of peripheral neurons with complex tissues. We demonstrate the ability of cancer spheroids to direct axonal growth and modulate excitability of nociceptive fibers in a 3D setting. We anticipate that this model will be applicable for closely monitoring innervation in various tissues, including somatic and visceral organs. The INV-MPS, hence, has tremendous potential for human-relevant drug discovery, creating opportunities for more ethical and clinically translatable approaches to study innervation in disease.

neuroscience↗

A multimodal 3D neuro-microphysiological system with neurite-trapping microelectrodes

Three-dimensional cell technologies as pre-clinical models are emerging tools for mimicking the structural and functional complexity of the nervous system. The accurate exploration of phenotypes in engineered 3D neuronal cultures, however, demands morphological, molecular and especially functional measurements. Particularly crucial is measurement of electrical activity of individual neurons with millisecond resolution. Current techniques rely on customized electrophysiological recording set-ups, characterized by limited throughput and poor integration with other readout modalities. Here we describe a novel approach, using multiwell glass microfluidic microelectrode arrays, allowing non-invasive electrical recording from engineered 3D neural tissues. We demonstrate parallelized studies with reference compounds, calcium imaging and optogenetic stimulation. Additionally, we show how microplate compatibility allows automated handling and high-content analysis of human induced pluripotent stem cell-derived neurons. This microphysiological platform opens up new avenues for high-throughput studies on the functional, morphological and molecular details of neurological diseases and their potential treatment by therapeutic compounds.

neuroscience↗

A synthetic RNA-based biosensor for fructose-1,6-bisphosphate that reports glycolytic flux

Metabolic heterogeneity, the occurrence of different metabolic phenotypes among cells, represents a key challenge in health and biotechnology. To unravel its molecular basis, tools probing metabolism of single cells are needed. While RNA devices harbor huge potential for the development of such tools, until today, it is challenging to create in vivo-functional sensors for any given metabolite. Here, we developed from scratch an RNA-based sensor for fructose-1,6-bisphosphate (FBP), a doubly phosphorylated intermediate of glycolysis. Starting from in vitro selection of an RNA aptamer and its structural analyses, we developed libraries of RNA-based regulatory devices with this aptamer and the hammerhead ribozyme as an actuator. Through FACS-seq-based high-throughput screening in yeast, we identified in vivo-functional FBP-sensing devices that generate fluorescent readout dependent on intracellular FBP concentration. As FBP reports the flux through glycolysis, the developed RNA device can be used to sense the glycolytic rate in single cells, offering unprecedented possibilities to investigate the causes of metabolic heterogeneity.

synthetic biology↗