Conductivity Sensor for Real‐time Monitoring of Magnesium Corrosion under Cell Culture Conditions

Abstract

1Introduction tested whether ac onductivity sensor could be used to monitor Mg degradation by detecting changes in ionic strength in real time,i nt hree physiologically appropriate fluids (a sodium chloride solution, phosphate buffered saline and ac ell culture medium maintained under the standard conditionsu sed for mammalian cell culture).Here we demonstrate that an electrochemical conductivity sensor, in combination with ap Hs ensor,r ecorded very different patternso fr eal-timec hanges in the ionice nvironmentc reated by Mg immersion and degradation in the three modele lectrolyte solutions,o ver a4 8-hour time period.

Conductivity as a Sensor for Monitoring Relative Magnesium Corrosion Rates in Real‐time, in Serum‐containing Media under Cell Culture Conditions

“…In this study, we have used a commercially available conductivity sensor with graphite electrodes to demonstrate an inexpensive and simple method of monitoring the corrosion of magnesium single crystals discs in cell culture medium under sterile cell culture conditions. This sensor has the capability of monitoring an increase in the total dissolved ion concentration as magnesium corrodes in our chosen model electrolyte solution, as has previously been reported . DMEM supplemented with 10 % fetal bovine serum (FBS) buffered in 5 % CO 2 was used as a model electrolyte solution in this study as this is a solution used routinely in cell culture studies to try to mimic in vivo body conditions.…”

“…A conductivity sensor that allows real‐time monitoring of magnesium corrosion under cell culture in a physiologically relevant fluid was successfully developed and demonstrated . For the ease of adoption by researchers in this area of study, we selected a commercially available conductivity sensor with graphite electrodes because it is very easy to use, it does not require calibration at different time intervals, it resists biofouling in the presence of proteins and living cells, and it can be used with corrosion solutions that contain calcium and magnesium.…”

“…Tw o-tailed student t-tests were used to compare unpolished to polished samples.T here were statistically significant differences between the two samples for corrosion rates (p < 0.001), change in measured osmolality between before and after (p < 0.001), change in conductivity between before and after (p = 0.006), and the total magnesium concentration by ICPMS (p < 0.001). (Table 1) 4Conclusions Ac onductivity sensor that allows real-time monitoring of magnesium corrosion under cell culture in aphysiologically relevant fluid was successfully developed and demon- strated [27].F or the ease of adoption by researchers in this area of study,w e selected ac ommercially available conductivity sensor with graphite electrodes because it is very easy to use,i td oes not require calibration at different time intervals,i tr esists biofouling in the presence of proteins and living cells,a nd it can be used with corrosion solutions that contain calcium and magnesium. As expected, the sensorw as very stable throughout the 45 hr ealtime measurementse xhibiting satisfactory performance for our application.…”

“…In this study,w eh ave used ac ommercially available conductivity sensor with graphite electrodes to demonstrate an inexpensive and simple method of monitoring the corrosion of magnesium single crystals discs in cell culture medium under sterile cell culture conditions.T his sensor has the capability of monitoring an increase in the total dissolvedi on concentration as magnesium corrodesi no ur chosen model electrolyte solution,a sh as previously been reported [27].D MEM supplemented with 10 %f etal bovine serum (FBS) buffered in 5% CO 2 was used as am odel electrolyte solution in this study as this is as olution used routinely in cell culture studies to try to mimic in vivo body conditions.T his medium containsm any additives requiredf or culturing cells in vitro,i ncluding amino acids,v itamins,g lucose,p henol red as av isual pH indicator, sodium bicarbonate,a nd sodium pyruvate, amongst others [ 28].D uringt he corrosion of magnesium, the corrosion products both deposit on the surface of the magnesium disc samples and dissolve in the corrosion media [2, 7-9, 28, 29].B ut the absolute amount of released ions in solution and rateo fc hange of the concentration of these ions will vary from solution to solution based on the ratio of production of deposits versus soluble ions. Thus,i nt his work, we used just one corrosion solutiont o compare sensorr esponses to corrosion rates obtained from differently processed magnesium single crystal samples.O ne of our magnesiums amples was unpolished and the other was polished and chemically etched.…”

Electrochemical Sensors Continuously Monitor Magnesium Biodegradation under Cell Culture Conditions

“…It was developed to evaluate and compare the biodegradation behavior of novel Mg materials and coatings, and it can be a valuable asset for initial screening. Additionally, we demonstrated the use of a conductivity sensor to monitor the biodegradation of Mg samples immersed in NaCl, PBS, and DMEM/F12 solutions . In this study, some elements of the CCS were applied to immersion tests carried out under cell culture conditions (37 °C, 5% CO 2 in air) to demonstrate the functionality and advantage of electrochemical sensors under these conditions.…”