Speaker
Description
Donor-derived graft fibrosis and ischemia reperfusion injury (IRI) remain a major determinant of transplant outcomes, yet perioperative tools provide limited real-time information on graft fibrosis, oxygenation, and response to emerging organ-repair therapies. One such therapy is mitochondrial transplantation (MTx) which delivers autologous mitochondria to injured grafts to restore bioenergetics, reduce oxidative stress, and support repair. Here, we develop ultrasound (US) and photoacoustic (PA) biomarkers for transplant quality fibrosis assessment and for monitoring mitochondrial transplantation to mitigate IRI.We have pioneered the use of quantitative ultrasound (QUS) analysis of radiofrequency backscatter with multiwavelength PA imaging to interrogate structure and function across clinical and large-animal transplant models. In a trial of 61 patients, pre-perfusion QUS H-scan analysis assessed donor-derived kidney fibrosis, while post-reperfusion PA spectra quantified hemoglobin oxygenation and acoustic-frequency signatures of IRI. In porcine kidney and liver IRI models, US/PA was used during normothermic perfusion or intraoperative reperfusion to evaluate autologous MTx, using oxygen saturation and backscatter/perfusion metrics as readouts of therapeutic response.In human kidney grafts, QUS-derived fibrosis strongly correlated with histology and predicted renal function at one year, while PA oxygenation distinguished reoxygenation differences in living and deceased donors. In liver IRI, MTx improved oxygen recovery and re-normalized the US backscatter patterns relative to controls. In kidney perfusion models, MTx improved renal artery flow, reduced intrarenal resistance, and increased cortical oxygenation.Together, these studies show the potential of US/PA for examining graft quality, monitoring emerging repair therapies in real time, and predicting organ recovery before irreversible dysfunction occurs.