Magnetic transverse unidirectional scattering and longitudinal displacement sensing in silicon nanodimer.

Unidirectional scattering, crucial for manipulating light at the nanoscale, has wide-ranging applications from optical manipulation to sensing. While traditionally achieved through interactions between electric multipoles or between electric and magnetic multipoles, reports on unidirectional scattering driven purely by magnetic multipoles are limited. In this study, we undertake a theoretical exploration of transverse unidirectional scattering induced by magnetic multipoles, employing tightly focused azimuthally polarized beams (APBs) in interaction with a silicon nanodimer comprising two non-concentric nanorings. Through numerical simulations and theoretical analysis, we validate the transverse unidirectional scattering, predominantly governed by magnetic dipolar and quadrupolar resonances. Moreover, the directionality of this unidirectional scattering shows a strong correlation with the longitudinal displacement of the nanodimer within a specific range, showcasing its potential for longitudinal displacement sensing. Our study advances optical scattering control in nanostructures and guides the design of on-chip longitudinal displacement sensors.

Screening patients in general practice for advanced chronic liver disease using an innovative IT solution: The Liver Toolkit.

BACKGROUND: Identifying patients with undiagnosed advanced chronic liver disease (ACLD) is a public health challenge. Patients with advanced fibrosis or compensated cirrhosis have much better outcomes than those with decompensated disease and may be eligible for interventions to prevent disease progression. METHODS: A cloud-based software solution ("the Liver Toolkit") was developed to access primary care practice software to identify patients at risk of ACLD. Clinical history and laboratory results were extracted to calculate aspartate aminotransferase-to-platelet ratio index and fibrosis 4 scores. Patients identified were recalled for assessment, including Liver Stiffness Measurement (LSM) via transient elastography. Those with an existing diagnosis of cirrhosis were excluded. RESULTS: Existing laboratory results of more than 32,000 adults across nine general practices were assessed to identify 703 patients at increased risk of ACLD (2.2% of the cohort). One hundred seventy-nine patients (26%) were successfully recalled, and 23/179 (13%) were identified to have ACLD (LSM ≥10.0 kPa) (10% found at indeterminate risk [LSM 8.0-9.9 kPa] and 77% low risk of fibrosis [LSM <8.0 kPa]). In most cases, the diagnosis of liver disease was new, with the most common etiology being metabolic dysfunction-associated steatotic liver disease (n=20, 83%). Aspartate aminotransferase-to-platelet ratio index ≥1.0 and fibrosis 4 ≥3.25 had a positive predictive value for detecting ACLD of 19% and 24%, respectively. Patients who did not attend recall had markers of more severe disease with a higher median aspartate aminotransferase-to-platelet ratio index score (0.57 vs. 0.46, p=0.041). CONCLUSIONS: This novel information technology system successfully screened a large primary care cohort using existing laboratory results to identify patients at increased risk ACLD. More than 1 in 5 patients recalled were found to have liver disease requiring specialist follow-up.

Au/Doc/Quer@PDA/A10-3.2 Nanoparticles for targeted treatment of docetaxel-resistant prostate cancer.

Docetaxel (Doc), as a first-line chemotherapy drug for prostate cancer (PC), often loses its therapeutic efficacy due to acquired resistance and lack of targeting specificity. Therefore, there is a need to develop a novel drug that can overcome Doc resistance and enhance its targeting ability to inhibit PC progression. In this study, we prepared Au/Doc/Quer@PDA/A10-3.2 nanoparticles (NPs) composite drug by encapsulating Doc and quercetin (Quer) within polydopamine (PDA)-coated Au NPs and further modifying them with RNA oligonucleotide aptamer A10-3.2. A10-3.2 was used for specific targeting of prostate-specific membrane antigen (PSMA)-positive PC cells (LNCaP). Quer was employed to reverse the resistance of Doc-resistant cell line (LNCaP/R) to Doc. Physical characterization using ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful preparation of Au/Doc/Quer@PDA/A10-3.2 NPs. Fluorescence imaging and flow cytometry experiments demonstrated the targeting ability of Au/Doc/Quer@PDA/A10-3.2 NPs towards PSMA-positive LNCaP/R cells. Cell proliferation, apoptosis, invasion, and migration experiments revealed that Quer reversed the resistance of LNCaP/R cells to Doc. Immunoblotting experiments further confirmed the mechanism behind sensitization of chemotherapy by Quer. Finally, we evaluated the therapeutic efficacy of Au/Doc/Quer@PDA/A10-3.2 NPs in a mouse model of PC. In conclusion, this study synthesized and validated a novel nano-composite drug (Au/Doc/Quer@PDA/A10-3.2 NPs) for combating Doc-resistant PC, which could potentially be applied in clinical treatment of PC.

Improving Conversations about Parkinson's Dementia.

BACKGROUND: People with Parkinson's disease (PD) have an increased risk of dementia, yet patients and clinicians frequently avoid talking about it due to associated stigma, and the perception that "nothing can be done about it". However, open conversations about PD dementia may allow people with the condition to access treatment and support, and may increase participation in research aimed at understanding PD dementia. OBJECTIVES: To co-produce information resources for patients and healthcare professionals to improve conversations about PD dementia. METHODS: We worked with people with PD, engagement experts, artists, and a PD charity to open up these conversations. 34 participants (16 PD; 6 PD dementia; 1 Parkinsonism, 11 caregivers) attended creative workshops to examine fears about PD dementia and develop information resources. 25 PD experts contributed to the resources. RESULTS: While most people with PD (70%) and caregivers (81%) shared worries about cognitive changes prior to the workshops, only 38% and 30%, respectively, had raised these concerns with a healthcare professional. 91% of people with PD and 73% of caregivers agreed that PD clinicians should ask about cognitive changes routinely through direct questions and perform cognitive tests at clinic appointments. We used insights from the creative workshops, and input from a network of PD experts to co-develop two open-access resources: one for people with PD and their families, and one for healthcare professionals. CONCLUSION: Using artistic and creative workshops, co-learning and striving for diverse voices, we co-produced relevant resources for a wider audience to improve conversations about PD dementia.

Surveillance MRI is associated with improved survival in patients with primary sclerosing cholangitis.

BACKGROUND: The benefits of regular surveillance imaging for cholangiocarcinoma in patients with primary sclerosing cholangitis (PSC) are unclear. Hence, we aimed to evaluate the impact of regular magnetic resonance cholangiopancreatography (MRCP) on outcomes of patients with PSC in Australia, where the practice of MRCP surveillance is variable. METHODS: The relationship between MRCP surveillance and survival outcomes was assessed in a multicenter, retrospective cohort of patients with PSC from 9 tertiary liver centers in Australia. An inverse probability of treatment weighting approach was used to balance groups across potentially confounding covariates. RESULTS: A total of 298 patients with PSC with 2117 person-years of follow-up were included. Two hundred and twenty patients (73.8%) had undergone MRCP surveillance. Regular surveillance was associated with a 71% reduced risk of death on multivariate weighted Cox analysis (HR: 0.29, 95% CI: 0.14-0.59, p < 0.001) and increased likelihood of having earlier endoscopic retrograde cholangiopancreatography from the date of PSC diagnosis in patients with a dominant stricture (p < 0.001). However, survival posthepatobiliary cancer diagnosis was not significantly different between both groups (p = 0.74). Patients who had surveillance of less than 1 scan a year (n = 41) had comparable survival (HR: 0.46, 95% CI 0.16-1.35, p = 0.16) compared to patients who had surveillance at least yearly (n = 172). CONCLUSIONS: In this multicenter cohort study that employed inverse probability of treatment weighting to minimize selection bias, regular MRCP was associated with improved overall survival in patients with PSC; however, there was no difference in survival after hepatobiliary cancer diagnosis. Further prospective studies are needed to confirm the benefits of regular MRCP and optimal imaging interval in patients with PSC.

Low rate of surgical site infections after liver transplantation: A 5-year retrospective cohort study.

BACKGROUND: Surgical site infection (SSI) after liver transplant (LT) is common, but no studies have been conducted in Australia. The purpose of this study was to determine the proportion of patients who developed an SSI post-LT in Australia's largest LT unit. METHODS: This was a single-center retrospective cohort study. We included all LT recipients who were aged 18 years or more and received their transplant between March 1, 2018 and April 1, 2023. The primary outcome was to determine the proportion of LT recipients who developed an SSI within 30 days of transplantation. RESULTS: There were 404 LTs performed during the study period, and 375 met inclusion criteria. Of these, 8% (n = 31/375) developed an SSI and were classified as superficial (3%, n = 12/375) or deep/organ space (5%, n = 19/375). The most common antibiotics used for prophylaxis were amoxicillin/clavulanate (75%, n = 281/375), followed by piperacillin/tazobactam (17%, n = 62/375). Independent risk factors associated with the development of SSI were Roux-en-Y hepaticojejunostomy (aOR 3.16, 95% CI 1.17-8.28, p = .02), operative time (per 60-min increment) (aOR 1.23, 95% CI 1.02-1.48), and re-operation (aOR 4.16, 95% CI 1.81-9.58, p < .01). Type of antibiotic received perioperatively was not significantly associated with SSI. CONCLUSION: SSI occurred in 8% of LT recipients and was predominantly related to operation-related factors rather than patient- or antibiotic-related factors.

Incidence, epidemiology, and outcomes of acute allograft rejection following liver transplantation in Australia.

Acute allograft rejection is a well-known complication of liver transplantation (LT). The incidence, epidemiology, and outcomes of acute rejection have not been well described in Australia. We retrospectively studied consecutive adults who underwent deceased donor LT at a single center between 2010 and 2020. Donor and recipient data at the time of LT and recipient outcomes were collected from a prospective LT database. Liver biopsy reports were reviewed, and only a graft's first instance of biopsy-proven acute rejection was analyzed. During the study period, 796 liver transplants were performed in 770 patients. Biopsy-proven rejection occurred in 34.9% of transplants. There were no significant changes in the incidence of rejection over time (linear trend p =0.11). The median time to the first episode of rejection was 71 days after LT: 2.2% hyperacute, 50.4% early (≤90 d), and 47.5% late rejection (>90 d). Independent risk factors for rejection were younger recipient age at transplant (aHR 0.98 per year increase, 95% CI: 0.97-1.00, p =0.01), and ABO-incompatible grafts (aHR 2.55 vs. ABO-compatible, 95% CI: 1.27-5.09, p <0.01) while simultaneous multiorgan transplants were protective (aHR 0.21 vs. LT only, 95% CI: 0.08-0.58, p <0.01). Development of acute rejection (both early and late) was independently associated with significantly reduced graft (aHR 3.13, 95% CI: 2.21-4.42, p <0.001) and patient survival (aHR 3.42, 95% CI: 2.35-4.98, p <0.001). In this 11-year Australian study, acute LT rejection occurred in 35%, with independent risk factors of younger recipient age and ABO-incompatible transplant, while having a simultaneous multiorgan transplant was protective. Acute rejection was independently associated with reduced graft and patient survival after adjustment for other factors.

CRYL1 is a Potential Prognostic Biomarker of Clear Cell Renal Cell Carcinoma Correlated with Immune Infiltration and Cuproptosis.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is a widespread urogenital neoplasm. However, the therapeutic efficacy of these methods is unsatisfactory. In-depth screening of biomarkers could aid early diagnosis and therapy and predict patient prognosis. METHODS: The GEO datasets were selected with specific criteria. Differentially expressed gene (DEG), weighted gene coexpression network analysis (WGCNA), protein-protein interaction, LASSO, random forest, and Cox regression analyses were applied to identify the independent prognostic biomarkers. Survival analysis, correlation with clinical features, gene set enrichment analysis (GSEA), GO enrichment, immune infiltration analysis, and correlation with cuproptosis-related genes were carried out to determine the prognostic value and possible molecular mechanisms of the TSVR. Wound healing assays, transwell assays, cell colony formation experiments, flow cytometry, and immunohistochemistry (IHC) analysis were used to validate the functional attributes of CRYL1. RESULTS: Four GEO datasets were included to screen for hub genes. DEG combined with WGCNA showed a key module with 300 genes having the strongest correlation with "survival state" (R2 = -0.24 and P = 7e-8); six genes were identified by LASSO, random forest, and Cytoscape. Finally, CRYL1 (hazard ratio (HR) = 2.01, P < 0.001) was selected as an independent prognostic biomarker. The higher CRYL1 expression group had better DFS and overall survival (OS). GSEA demonstrated that the CRYL1-related DEGs were enriched mainly in the metabolism of sugar, fat, and amino acids. CRYL1 is positively correlated with FDX1 and the LIAS pathway, which are important molecule involved in cuproptosis. CRYL1 affects the infiltration abundance of four immune cells and can predict a positive OS. Wound healing, transwell, cell colony formation, and flow cytometry assays demonstrated that CRYL1 silencing enhances migration and proliferation and leads to a decreased apoptotic ratio. IHC analysis suggested that CRYL1 was highly expressed in adjacent tissues. CONCLUSIONS: CRYL1 is a robust predictive marker for clinicopathological characteristics and survival status in ccRCC patients.

Incorporating a hemodialysis filter into a commercial normothermic perfusion system to facilitate long-term preservation of human split-livers.

BACKGROUND: Normothermic machine perfusion (NMP) allows for the assessment and resuscitation of ex-vivo human livers prior to transplantation. Commercially available NMP systems are closed circuits that accumulate metabolic waste and cytokines over time, potentially limiting organ preservation times. Dialysis has been proposed as a method to remove waste and excess fluid from such systems. This study aimed to demonstrate the utility of integrating dialysis into a commercially available system by quantifying solute removal. METHODS: A dialysis filter was attached in parallel to a commercially available liver perfusion system. Three livers declined for transplantation were split before undergoing long-term NMP with blood using the modified system. During perfusion, dialysate flow rates were set in the range of 100-600 mL/h for short periods of time. At each flow rate, perfusate and spent dialysate samples were collected and analyzed for solute clearance. RESULTS: The addition of dialysis to a commercial NMP system removed water-soluble waste and helped regulate electrolyte concentrations. Interleukin-6 was successfully removed from the perfusate. Solute clearance was proportional to dialysate flow rate. A guide for our perfusion setup was created for the appropriate selection of dialysis flow rates and duration based on real-time perfusate composition. CONCLUSIONS: Dialysis circuits can efficiently remove waste and regulate perfusate composition, and can be easily incorporated to improve the performance of commercially available systems. Quantification of the effect of dialysis on perfusate composition enables refined dialysis control to optimize electrolyte profiles and avoid the over- or under-correction of key solutes.

Drug-induced liver injury from selective androgen receptor modulators, anabolic-androgenic steroids and bodybuilding supplements in Australia.

BACKGROUND: Reports of DILI due to herbal and dietary supplements have been increasing over time. AIMS: To characterise clinical, laboratory and histopathological phenotypes and outcomes of drug-induced liver injury (DILI) due to anabolic-androgenic steroids (AAS), selective androgen receptor modulators (SARMs), and bodybuilding supplements (BBS) in Australia. METHODS: Retrospective case series. Patients presented to nine Australian tertiary hospitals, 2017-2023. DILI was defined biochemically and patients were included if their treating physician attributed DILI to preceding use of AAS, SARMs or BBS. Primary endpoint was time to normalisation of liver biochemistry. Secondary endpoints were hospitalisation for investigation or management of DILI, death attributable to liver injury, and liver transplantation. RESULTS: Twenty-three cases of DILI were identified, involving 40 drugs: 18 AAS, 14 SARMs and eight BBS. Patients were predominantly male (22/23), with median age 30 years (IQR 26-42). Most were symptomatic (21/23). Median latency of onset was 58 days (IQR 28-112 days) from drug commencement. Most patients (17/23) were admitted to hospital. Based on updated Roussel Uclaf Causality Assessment Method, DILI was possible in 17/23, probable in 2/23 and unlikely in 4/23. Median time to normalisation of liver biochemistry was 175 days (IQR 70-292 days) from presentation. Three (3/23) were treated with corticosteroids, 14/23 were treated for itch, and one (1/23) underwent liver transplantation. There were no deaths. CONCLUSIONS: The prognosis of DILI from AAS, SARMs and BBS is good although liver transplantation may rarely be required. A detailed drug history is important in uncovering DILI due to these supplements.

Reply to Allaire, M.; Thabut, D. Comment on "Wu et al. Baveno VII Criteria Is an Accurate Risk Stratification Tool to Predict High-Risk Varices Requiring Intervention and Hepatic Events in Patients with Advanced Hepatocellular Carcinoma. Cancers 2023, 15, 2480".

We thank Allaire et al [...].

Targeting the SphK1/S1P/PFKFB3 axis suppresses hepatocellular carcinoma progression by disrupting glycolytic energy supply that drives tumor angiogenesis.

BACKGROUND: Hepatocellular carcinoma (HCC) remains a leading life-threatening health challenge worldwide, with pressing needs for novel therapeutic strategies. Sphingosine kinase 1 (SphK1), a well-established pro-cancer enzyme, is aberrantly overexpressed in a multitude of malignancies, including HCC. Our previous research has shown that genetic ablation of Sphk1 mitigates HCC progression in mice. Therefore, the development of PF-543, a highly selective SphK1 inhibitor, opens a new avenue for HCC treatment. However, the anti-cancer efficacy of PF-543 has not yet been investigated in primary cancer models in vivo, thereby limiting its further translation. METHODS: Building upon the identification of the active form of SphK1 as a viable therapeutic target in human HCC specimens, we assessed the capacity of PF-543 in suppressing tumor progression using a diethylnitrosamine-induced mouse model of primary HCC. We further delineated its underlying mechanisms in both HCC and endothelial cells. Key findings were validated in Sphk1 knockout mice and lentiviral-mediated SphK1 knockdown cells. RESULTS: SphK1 activity was found to be elevated in human HCC tissues. Administration of PF-543 effectively abrogated hepatic SphK1 activity and significantly suppressed HCC progression in diethylnitrosamine-treated mice. The primary mechanism of action was through the inhibition of tumor neovascularization, as PF-543 disrupted endothelial cell angiogenesis even in a pro-angiogenic milieu. Mechanistically, PF-543 induced proteasomal degradation of the critical glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, thus restricting the energy supply essential for tumor angiogenesis. These effects of PF-543 could be reversed upon S1P supplementation in an S1P receptor-dependent manner. CONCLUSIONS: This study provides the first in vivo evidence supporting the potential of PF-543 as an effective anti-HCC agent. It also uncovers previously undescribed links between the pro-cancer, pro-angiogenic and pro-glycolytic roles of the SphK1/S1P/S1P receptor axis. Importantly, unlike conventional anti-HCC drugs that target individual pro-angiogenic drivers, PF-543 impairs the PFKFB3-dictated glycolytic energy engine that fuels tumor angiogenesis, representing a novel and potentially safer therapeutic strategy for HCC.

Microbial Contamination During Long-term Ex Vivo Normothermic Machine Perfusion of Human Livers.

BACKGROUND: Normothermic machine perfusion permits the ex vivo preservation of human livers before transplantation. Long-term perfusion for days-to-weeks provides the opportunity for enhanced pretransplant assessment and potential regeneration of organs. However, this risks microbial contamination and infection of the recipient if the organ is transplanted. An understanding of perfusate microbial contamination is required to inform infection control procedures and antimicrobial prophylaxis for this technology. METHODS: We modified a liver perfusion machine for long-term use by adding long-term oxygenators and a dialysis filter. Human livers that were not suitable for transplantation were perfused using a red-cell-based perfusate under aseptic and normothermic conditions (36 °C) with a goal of 14 d. Cephazolin was added to the perfusate for antimicrobial prophylaxis. Perfusate and bile were sampled every 72 h for microbial culture. RESULTS: Eighteen partial human livers (9 left lateral segment grafts and 9 extended right grafts) were perfused using our perfusion system. The median survival was 7.2 d. All organs surviving longer than 7 d (9/18) had negative perfusate cultures at 24 and 48 h. Half of the grafts (9/18) became culture-positive by the end of perfusion. Microbial contaminants included Gram-negative ( Pseudomonas species, Proteus mirabilis, Stenotrophomonas maltophilia ) and Gram-positive bacteria ( Staphylococcus epidermidis , Enterococcus faecalis , and Bacillus species) as well as yeast ( Candida albicans ). CONCLUSIONS: Microbial contamination of perfusate is common during long-term perfusion of human livers with both exogenous and endogenous sources. Enhanced infection control practices and review of targeted antimicrobial prophylaxis are likely to be necessary for translation into the clinical arena.

The incidence of adverse outcome in donors after living donor liver transplantation: A meta-analysis of 60,829 donors.

The scarcity of liver grafts has prompted developments in living donor liver transplantations (LDLT), with previous literature illustrating similar outcomes in recipients compared to deceased donor transplants. However, significant concerns regarding living donor morbidity and mortality have yet to be examined comprehensively. This study aims to provide estimates of the incidence of various outcomes in living liver donors. In this meta-analysis, Medline and Embase were searched from inception to July 2022 for articles assessing the incidence of outcomes in LDLT donors. Complications in the included studies were classified into respective organ systems. Analysis of incidence was conducted using a generalized linear mixed model with Clopper-Pearson intervals. Eighty-seven articles involving 60,829 living liver donors were included. The overall pooled incidence of complications in LDLT donors was 24.7% (CI: 21.6%-28.1%). The incidence of minor complications was 17.3% (CI: 14.7%-20.3%), while the incidence of major complications was lower at 5.5% (CI: 4.5%-6.7%). The overall incidence of donor mortality was 0.06% (CI: 0.0%-0.1%) in 49,027 individuals. Psychological complications (7.6%, CI: 4.9%-11.5%) were the most common among LDLT donors, followed by wound-related (5.2%, CI: 4.4%-6.2%) and respiratory complications (4.9%, CI: 3.8%-6.3%). Conversely, cardiovascular complications had the lowest incidence among the subgroups at 0.8% (CI: 0.4%-1.3%). This study presents the incidence of post-LDLT outcomes in living liver donors, illustrating significant psychological, wound-related, and respiratory complications. While significant advancements in recent decades have contributed towards decreased morbidity in living donors, our findings call for targeted measures and continued efforts to ensure the safety and quality of life of liver donors post-LDLT.

Immunogenicity and Vaccine Shedding After 1 or 2 Doses of rVSVΔG-ZEBOV-GP Ebola Vaccine (ERVEBO®): Results From a Phase 2, Randomized, Placebo-controlled Trial in Children and Adults.

BACKGROUND: The rVSVΔG-ZEBOV-GP vaccine (ERVEBO®) is a single-dose, live-attenuated, recombinant vesicular stomatitis virus vaccine indicated for the prevention of Ebola virus disease (EVD) caused by Zaire ebolavirus in individuals 12 months of age and older. METHODS: The Partnership for Research on Ebola VACcination (PREVAC) is a multicenter, phase 2, randomized, double-blind, placebo-controlled trial of 3 vaccine strategies in healthy children (ages 1-17) and adults, with projected 5 years of follow-up (NCT02876328). Using validated assays (GP-ELISA and PRNT), we measured antibody responses after 1-dose rVSVΔG-ZEBOV-GP, 2-dose rVSVΔG-ZEBOV-GP (given on Day 0 and Day 56), or placebo. Furthermore, we quantified vaccine virus shedding in a subset of children's saliva using RT-PCR. RESULTS: In total, 819 children and 783 adults were randomized to receive rVSVΔG-ZEBOV-GP (1 or 2 doses) or placebo. A single dose of rVSVΔG-ZEBOV-GP increased antibody responses by Day 28 that were sustained through Month 12. A second dose of rVSVΔG-ZEBOV-GP given on Day 56 transiently boosted antibody concentrations. In vaccinated children, GP-ELISA titers were superior to placebo and non-inferior to vaccinated adults. Vaccine virus shedding was observed in 31.7% of children, peaking by Day 7, with no shedding observed after Day 28 post-dose 1 or any time post-dose 2. CONCLUSIONS: A single dose of rVSVΔG-ZEBOV-GP induced robust antibody responses in children that was non-inferior to the responses induced in vaccinated adults. Vaccine virus shedding in children was time-limited and only observed after the first dose. Overall, these data support the use of rVSVΔG-ZEBOV-GP for the prevention of EVD in at-risk children. Clinical Trials Registration. The study is registered at ClinicalTrials.gov (NCT02876328), the Pan African Clinical Trials Registry (PACTR201712002760250), and the European Clinical Trials Register (EudraCT number: 2017-001798-18).

Indocyanine green: A novel marker for assessment of graft quality during ex situ normothermic machine perfusion of human livers.

BACKGROUND: Ex situ machine perfusion facilitates the assessment of livers prior to transplantation. However, currently available markers of liver function poorly predict long-term graft function. Indocyanine green (ICG) is a liver-specific dye which, although common in vivo, has never been comprehensively evaluated for the assessment of graft quality during ex situ machine perfusion. This study aimed to assess the utility of ICG in the ex situ setting. METHODS: Using a customized long-term perfusion system, human livers that were not suitable for transplantation were perfused using a red cell-based perfusate. ICG was delivered into the perfusate on days 0, 1, and 4 to assess ICG clearance (spectrophotometric absorbance at 805 nm) and ICG fluorescence (near-infrared camera). RESULTS: Sixteen partial livers were perfused for a median duration of 172 h (7.2 days). On day 0, the median ICG perfusate disappearance rate (PDR) was 7.5%/min and the median ICG retention at 15 min was 9.9%. Grafts that survived ≥7 days had a significantly higher median ICG PDR on day 0 (14.5%/min vs. 6.5%/min, p = 0.005) but not on days 1 or 4. ICG perfusion demonstrated that long-surviving grafts had a significantly lower median red-value (89.8 vs. 118.6, p = 0.011) and a significantly lower median blue-value (12.9 vs. 22.6, p = 0.045) than short-surviving grafts. CONCLUSION: ICG is a novel marker for the assessment of liver function during ex situ normothermic machine perfusion. ICG PDR and quantitative ICG perfusion can distinguish between long- and short-surviving grafts and demonstrate the utility of ICG in the assessment of graft quality prior to transplant.