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Eddington, D. T.

Publications and source records attributed to Eddington, D. T..

2 recordsLinked to original sources

Emulating clinical pressure waveforms in cellculture using an Arduino-controlled 3D-printed platform for 96-well plates

High blood pressure is the primary risk factor for heart disease, the leading cause of death globally. Despite this, current methods to replicate physiological pressures in-vitro remain limited in sophistication and throughput. Single-chamber exposure systems allow for only one pressure condition to be studied at a time and the application of dynamic pressure waveforms is currently limited to simple sine, triangular, or square waves. Here, we introduce a high-throughput hydrostatic pressure exposure system for 96-well plates. The platform can deliver a fully-customizable pressure waveform to each column of the plate, for a total of 12 simultaneous conditions. Using clinical waveform data, we are able to replicate real patients blood pressures as well as other medically-relevant pressures within the body and have assembled a small patient-derived waveform library of some key physiological locations. As a proof of concept, human umbilical vein endothelial cells (HUVECs) survived and proliferated under pressure for 3 days under a wide range of static and dynamic blood pressures ranging from 10 mm Hg to 400 mm Hg. Interestingly, pathologic and supraphysiologic pressure exposures did not inhibit cell proliferation. By integrating with, rather than replacing, ubiquitous lab cultureware it is our hope that this device will facilitate the incorporation of hydrostatic pressure into standard cell culture practice.

bioengineering↗

96-Well Oxygen Control Using a 3D-Printed Device

Oxygen concentration varies tremendously within the body and has proven to be a critical variable in cell differentiation, proliferation, and drug metabolism among many other physiological processes. Currently, researchers study the gass role in biology using low-throughput gas-control incubators or hypoxia chambers in which all cells in a vessel are exposed to a single oxygen concentration. Here, we introduce a device which can simultaneously deliver 12 unique oxygen concentrations to cells in a 96-well plate and seamlessly integrate into biomedical research workflows. The device inserts into 96-well plates and delivers gas to the headspace thus avoiding undesirable contact with media. This simple approach isolates each well using gas-tight pressure resistant gaskets effectively creating 96 "mini-incubators". Each of the twelve columns of the plate is supplied by a distinct oxygen concentration from a gas-mixing gradient generator supplied by two feed gases. The wells within each column are then supplied by an equal flow-splitting distribution network. Using equal feed flow rates, concentrations ranging from 0.6% to 20.5% were generated within a single plate. A549 lung carcinoma cells were then used to show that O2 levels below 9% caused a stepwise increase in cell death for cells treated with the hypoxia-activated anti-cancer drug Tirapirizamine (TPZ). Additionally, the 96-well plate was further leveraged to simultaneously test multiple TPZ concentrations over an oxygen gradient and generate a 3D dose response landscape. The results presented here show how microfluidic technologies can be integrated into, rather than replace, ubiquitous biomedical labware allowing for increased throughput oxygen studies.

bioengineering↗