Incubator-independent perfusion system integrated with microfluidic device for continuous electrophysiology and microscopy readouts

Abstract

Advances in primary and stem cell derived neuronal cell culture techniques and abundance of available neuronal cell types have enabled in vitro neuroscience as a substantial approach to model in vivo neuronal networks. Survival of the cultured neurons is inevitably dependent on the cell culture incubators to provide stable temperature and humidity and to supply required CO2 levels for controlling the pH of culture medium. Therefore, imaging and electrophysiology recordings outside of the incubator are often limited to the short-term experimental sessions. This restricts our understanding of physiological events to the short snapshots of recorded data while the major part of temporal data is neglected. Multiple custom-made and commercially available platforms like integrated on-stage incubators have been designed to enable long-term microscopy. Nevertheless, long-term high-spatiotemporal electrophysiology recordings from developing neuronal networks needs to be addressed. In the present work an incubator-independent polydimethylsiloxane (PDMS)-based double-wall perfusion chamber was designed and integrated with multi-electrode arrays (MEAs) electrophysiology and compartmentalized microfluidic device to continuously record from engineered neuronal networks at sub-cellular resolution. Cell culture media underwent iterations of conditioning to the ambient CO2 and adjusting its pH to physiological ranges to retain a stable pH for weeks outside of the incubator. Double-wall perfusion chamber and an integrated air bubble trapper reduced media evaporation and osmolality drifts of the conditioned media for two weeks. Aligned microchannel-microfluidic device on MEA electrodes allowed neurite growth on top of the planar electrodes and amplified their extracellular activity. This enabled continuous sub-cellular resolution imaging and electrophysiology recordings from developing networks and their growing neurites. The on-chip versatile and self-contained system provides long-term, continuous and high spatiotemporal access to the network data and offers a robust in vitro platform with many potentials to be applied on advanced cell culture systems including organ-on-chip and organoid models.

Porous Structural Microfluidic Device for Biomedical Diagnosis: A Review

“…Synthetic polymers are ubiquitous materials used in a wide variety of applications because of their structural and mechanical properties [ 67 ]. The application of polymers as a discontinuous dielectric structure in wearable devices offers a wide range of applications in health monitoring and medical fields [ 27 , 68 , 69 , 70 ]. The rapid development of porous polymers in the last few years has been attributed to the continuous development of modern organic synthesis, advanced polymerization techniques and nanotechnology [ 71 ].…”

Guiding organs-on-chips towards applications: a balancing act between integration of advanced technologies and standardization

“…The on-chip quantification of cell dynamics and interactions is thus facilitated and could be instrumental for progressing the state of the art in disease modeling and drug development. Several imaging modalities have been successfully applied to microfluidic systems, ranging from standard brightfield and fluorescent imaging (Mencattini et al, 2022;Habibey, 2023), multiphoton imaging (Mazzarda et al, 2020;Lohasz et al, 2021), calcium signaling detection (Mazzarda et al, 2020), bioluminescence imaging (Araújo-Gomes et al, 2023), and photoacoustic (Jin et al, 2021) and light sheet microscopy (Fan et al, 2021). In addition, the miniaturization of imaging chambers and channels presents significant advantages: i) precise molecule manipulation, ii) control over the physicochemical properties of the microenvironment, iii) higher sample concentration (Miyake et al, 2008), and iv) increased signalto-noise ratio (Campos et al, 2011).…”

“…Microfluidic sensors can also be potential alternatives for standard enzyme-linked immunosorbent assays (ELISA) by increasing detection limits and circumventing the need for high sample volumes (Shin et al, 2017). Potential applications of such systems include, but are not limited to, the assessment of drug-induced kidney (Kann et al, 2023), cardiac (Shin et al, 2016;Tanumihardja et al, 2021), gut (Khalid et al, 2022) and liver (Busche et al, 2022) toxicity, screening oncology drug efficacy screenings (Dornhof et al, 2022), and electrophysiology measurements (Habibey, 2023).…”

Advances in Microfluidics Techniques for Rapid Detection of Pesticide Residues in Food

“…Microfluidic devices [109,110] offer a viable solution to achieve the detection o bamate and overcome the issues associated with complex procedures and transpor Interestingly, microfluidics widely utilize unitary and multiple signal readouts [111 Microfluidic devices [109,110] offer a viable solution to achieve the detection of carbamate and overcome the issues associated with complex procedures and transportation. Interestingly, microfluidics widely utilize unitary and multiple signal readouts [111][112][113][114][115]. For instance, based on colorimetry, M.D.…”