Use of Raman spectroscopy to measure mitochondrial redox state as a marker of tissue injury in donor livers

Abstract With more than five times the number of patients on the wait list than will receive a donor organ in the United Statesthe field of transplantation is facing a serious donor shortage crisisThe lack of available biomarkers for assessment of organ injury due to ischemia injury results in unnecessary waste of high quality organsWe aim to establish mitochondrial redox statemeasured on the tissue surface with resonance Raman spectroscopyRRSas a biomarker for cold and warm ischemic injury in donor liver organsWe have previously demonstrated mitochondrial redox statequantified as the resonance Raman reduced mitochondrial ratioRMRas a marker of myocardial failureIn recent pilot workwe measuredRMR from an ischemia liver and demonstrated a gradual increase during ischemiaIn this projectwe will optimize our prototype RRS system for liver measurements and build one dedicated to these studiesWe will create an enhanced spectral library to allow accurate quantification of liverRMR by our regression algorithmFinallywe will characterize our marker in a model of cold ischemia in rat donor liversIt is our hypothesis thatRMR will predict the extent of ischemic damage and therefore the viability of the liver tissue on reperfusionThe availability of a real time marker for ischemic damage would be transformative and would potentially increase the number of organs considered viable for transplant Narrative There is a serious shortage of donor organs for patients with a range of diseasesReliable markers of liver function would help to increase the supply by providing a way to determine if a stored donor organ is still viableWe will develop and study a marker of liver function in donor livers based on mitochondria