Microoxygraph Device for Biosensoristic Applications

Abstract

Oxygen consumption rate (OCR) is a significant parameter helpful to determinein vitrorespiratory efficiency of living cells. Oxygen is an excellent oxidant and its electrocatalytic reduction on a noble metal allows accurately detecting it. By means of microfabrication technologies, handy, low-cost, and disposable chip can be attained, minimizing working volumes and improving sensitivity and response time. In this respect, here is presented a microoxygraph device (MOD), based on Clark’s electrode principle, displaying many advantageous features in comparison to other systems. This lab-on-chip platform is composed of a three-microelectrode detector equipped with a microgrooved electrochemical cell, sealed with a polymeric reaction chamber. Au working/counter electrodes and Ag/AgCl reference electrode were fabricated on a glass slide. A microchannel was realized by photoresist lift-off technique and a polydimethylsiloxane (PDMS) nanoporous film was integrated as oxygen permeable membrane (OPM) between the probe and the microreaction chamber. Electrochemical measurements showed good reproducibility and average response time, assessed by periodic injection and suction of a reducing agent. OCR measurements on 3T3 cells, subjected, in real time, to chemical stress on the respiratory chain, were able to show that this chip allows performing consistent metabolic analysis.

Analysis of oxygen transport in microfluidic bioreactors for cell culture and organ‐on‐chip applications

“…26 Moreover, almost all drugs interact with the liver, as the largest organ of the body, due to its metabolism and detoxification functions. Among all cases of drug failure, it is estimated that cost of safety liabilities for cardiovascular systems is 45%, while 32% are due to hepatotoxicity.…”

“…Among all cases of drug failure, it is estimated that cost of safety liabilities for cardiovascular systems is 45%, while 32% are due to hepatotoxicity. 26 Normal values of oxygen partial pressure (PaO 2 ) in the cellular microenvironment are determined in various human tissues based on organ function and cellular behavior. Therefore, liver toxicity plays a dramatic role in the development of the new drug.…”

“…Among all cases of drug failure, it is estimated that cost of safety liabilities for cardiovascular systems is 45%, while 32% are due to hepatotoxicity. 26 Moreover, almost all drugs interact with the liver, as the largest organ of the body, due to its metabolism and detoxification functions. Therefore, liver toxicity plays a dramatic role in the development of the new drug.…”

“…11 In addition, high oxygen tension (hyperoxia) may result in the generation of elevated level of reactive oxygen species in pathological pathways. 13,14 Importantly, in multiple-OoC systems, two or more bioreactors, which might require different levels of oxygen tension, are interconnected. 13,14 Importantly, in multiple-OoC systems, two or more bioreactors, which might require different levels of oxygen tension, are interconnected.…”

“…12 Thus, the balance of oxygen availability and oxygen consumption is necessary to maintain normoxia and to prevent hyperoxia and hypoxia or even complete absence of oxygen (anoxia). 13,14 Importantly, in multiple-OoC systems, two or more bioreactors, which might require different levels of oxygen tension, are interconnected. In this way, the prediction and control of oxygen tension in each bioreactor is a critical design consideration.…”