Influence of Environmental Variables on In Vitro Performance

To date, many in vitro Mg biodegradation tests are not being carried out in a reproducible or clear manner. In many cases, values of important variables (such as pH) are not reported, or are not correctly controlled throughout the experiments; in other cases, values are being used which do not mimic physiological conditions. Typical issues include the use of unphysiological temperatures or alkalised media, as well as set-ups with either unadjusted or uncontrolled pH values, far outside the body’s natural range. In many studies, it is difficult to determine what was and was not controlled—this also makes it difficult to compare studies. The influences and impacts of experimental parameters such as pH, solution composition and temperature are discussed in this chapter. It is shown that it is very difficult to relate results from studies performed under non-physiological conditions to in vivo performance.