Development of Organ-on-a-Chip System with Continuous Flow in Simulated Microgravity.

Organ-on-a-chip (OOC) is an innovative microfluidic device mimicking the structure and functionality of real tissue. OOCs typically involve cell culture with microfluidics to emulate the biological forces of different organ tissues and disease states, providing a next-generation experimental platform. When combined with simulated microgravity conditions, such as those produced by random positioning machines, they offer unique insights into disease processes. Microgravity has been shown to affect cellular behaviors, like proliferation and viability, though its influence on cell physiology is not fully explored. The primary objective of this study was to develop an OOC model with continuous flow under simulated microgravity. Cells cultured in static (non-continuous-flow) conditions exhibited clear growth reduction under microgravity conditions, showing more pronounced difference compared to continuous-flow conditions using an OOC setup. Although our results show that A549 cell viability under continuous flow decreased in microgravity compared to normogravity, this study demonstrates the successful development of a system capable of providing continuous flow in organ-on-a-chip (OOC) models within a random positioning machine.

Single Step Isolation of Extracellular Vesicles from Large-Volume Samples with a Bifurcated A4F Microfluidic Device.

Extracellular vesicles (EVs) hold immense potential for various biomedical applications, including diagnostics, drug delivery, and regenerative medicine. Nevertheless, the current methodologies for isolating EVs present significant challenges, such as complexity, time consumption, and the need for bulky equipment, which hinders their clinical translation. To address these limitations, we aimed to develop an innovative microfluidic system based on cyclic olefin copolymer-off-stoichiometry thiol-ene (COC-OSTE) for the efficient isolation of EVs from large-volume samples in a continuous manner. By utilizing size and buoyancy-based separation, the technology used in this study achieved a significantly narrower size distribution compared to existing approaches from urine and cell media samples, enabling the targeting of specific EV size fractions in future applications. Our innovative COC-OSTE microfluidic device design, utilizing bifurcated asymmetric flow field-flow fractionation technology, offers a straightforward and continuous EV isolation approach for large-volume samples. Furthermore, the potential for mass manufacturing of this microfluidic device offers scalability and consistency, making it feasible to integrate EV isolation into routine clinical diagnostics and industrial processes, where high consistency and throughput are essential requirements.

Bifurcated Asymmetric Field Flow Fractionation of Nanoparticles in PDMS-Free Microfluidic Devices for Applications in Label-Free Extracellular Vesicle Separation.

Extracellular vesicles are small membrane-bound structures that are released by cells and play important roles in intercellular communication garnering significant attention in scientific society recently due to their potential as diagnostic and therapeutic tools. However, separating EVs from large-volume samples remains a challenge due to their small size and low concentration. In this manuscript, we presented a novel method for separating polystyrene beads as control and extracellular vesicles from large sample volumes using bifurcated asymmetric field flow fractionation in PDMS-free microfluidic devices. Separation characteristics were evaluated using the control system of polystyrene bead mix, which offers up to 3.7X enrichment of EV-sized beads. Furthermore, in the EV-sample from bioreactor culture media, we observed a notable population distribution shift of extracellular vesicles. Herein presented novel PDMS-free microfluidic device fabrication protocol resulted in devices with reduced EV-loss compared to size-exclusion columns. This method represented an improvement over the current state of the art in terms of EV separation from large sample volumes through the use of novel field flow fractionation design.