Revitalizing liver function in mice with liver failure through transplantation of 3D-bioprinted liver with expanded primary hepatocytes.

The utilization of three-dimensional (3D) bioprinting technology to create a transplantable bioartificial liver emerges as a promising remedy for the scarcity of liver donors. This study outlines our strategy for constructing a 3D-bioprinted liver, using in vitro-expanded primary hepatocytes recognized for their safety and enhanced functional robustness as hepatic cell sources for bioartificial liver construction. In addition, we have developed bioink biomaterials with mechanical and rheological properties, as well as printing capabilities, tailored for 3D bioprinting. Upon heterotopic transplantation into the mesentery of tyrosinemia or 90% hepatectomy mice, our 3D-bioprinted liver effectively restored lost liver functions, consequently extending the life span of mice afflicted with liver injuries. Notably, the inclusion of an artificial blood vessel in our 3D-bioprinted liver allowed for biomolecule exchange with host blood vessels, demonstrating, in principle, the rapid integration of the bioartificial liver into the host vascular system. This model underscores the therapeutic potential of transplantation for the treatment of liver failure diseases.

[Extracorporeal Support Strategies in Liver Failure - Focus on Albumin Dialysis and Therapeutic Plasma Exchange]. / Extrakorporale Unterstützungsstrategien beim Leberversagen.

Combining albumin dialysis for the removal of hydrophobic substances with classical haemodialysis in the treatment of acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) has a strong theoretical rational and clinical data showed a positive effect on laboratory and partly clinical characteristics of ALF and ACLF. However, neither the MARS nor the Prometheus System has so far been able to demonstrate a mortality benefit in ALF or ACLF patients. To date, only the use of therapeutic plasma exchange (TPE) has demonstrated significant removal of pathogen-associated (PAMPs), damage-associated molecular patterns (DAMPs) and pro-inflammatory cytokines. In addition, TPE also acts simultaneously by replacing protective but depleted mediators, thus improving multiple key pathophysiological principles of both ALF and ACLF. In ALF, both high-volume and standard-volume TPE showed a significant improvement in survival. The data on the use of TPE in ACLF is still sparse, with only two Chinese monocentric studies in patients with exclusively hepatitis B-associated ACLF suggesting potentially improved survival with TPE. The currently recruiting APACHE study will include patients with the modern EASL-CLIF definition of ACLF.

Management of pediatric liver failure with therapeutic plasma exchange and continuous renal replacement therapy: A retrospective observational study.

Liver failure represents a critical medical condition, marked by the rapid decline of hepatic functions. Emerging therapies, notably therapeutic plasma exchange (TPE) and continuous venovenous hemodiafiltration (CVVHDF), have demonstrated potential in mitigating these conditions through their roles in detoxification and hepatic support. The utility of these treatments, whether applied individually or in tandem, constitutes a significant area of research concerning the management of liver failure in pediatric patients. This study aims to evaluate the role and efficacy of TPE or TPE combined with CVVHDF in the treatment of liver failure among children. This retrospective study was conducted in a LTICU by reviewing the medical history of pediatric patients aged 1 month to 18 years. Patients were admitted between January 1, 2021 and December 1, 2023 due to acute liver failure or acute-chronic liver failure. The study evaluated those who received TPE or continuous renal replacement therapy combined with TPE. In statistical analyses, a P-value of <.05 was considered statistically significant. The study involved 24 patients with liver failure, comprising 13 males and 11 females. Sixteen patients (66.6%) received only TPE, while 8 patients (33.4%) were treated with TPE and CVVHDF. For patients treated only with TPE, the median INR reduced from 3.1 to 1.26, alanine aminotransferase from 1255 to 148, and aspartate aminotransferase from 2189 to 62. Similar significant reductions were observed in the TPE and CVVHDF group: INR from 3.9 to 1.26, alanine aminotransferase from 1749 to 1148, and aspartate aminotransferase from 1489 to 62. These changes were statistically significant with P-values of .01 for each parameter in both groups. Overall, 14 patients survived without requiring a liver transplant, while 4 patients underwent liver transplantation. Our study on pediatric liver failure treatment shows that both standalone TPE and its combination with CVVHDF are effective, especially as a bridge to transplantation. With 58% transplant-free survival, these therapies demonstrate significant clinical improvements. Future multicentric studies are needed for broader validation of these findings in liver failure management.

A comprehensive review of advances in hepatocyte microencapsulation: selecting materials and preserving cell viability.

Liver failure represents a critical medical condition with a traditionally grim prognosis, where treatment options have been notably limited. Historically, liver transplantation has stood as the sole definitive cure, yet the stark disparity between the limited availability of liver donations and the high demand for such organs has significantly hampered its feasibility. This discrepancy has necessitated the exploration of hepatocyte transplantation as a temporary, supportive intervention. In light of this, our review delves into the burgeoning field of hepatocyte transplantation, with a focus on the latest advancements in maintaining hepatocyte function, co-microencapsulation techniques, xenogeneic hepatocyte transplantation, and the selection of materials for microencapsulation. Our examination of hepatocyte microencapsulation research highlights that, to date, most studies have been conducted in vitro or using liver failure mouse models, with a notable paucity of experiments on larger mammals. The functionality of microencapsulated hepatocytes is primarily inferred through indirect measures such as urea and albumin production and the rate of ammonia clearance. Furthermore, research on the mechanisms underlying hepatocyte co-microencapsulation remains limited, and the practicality of xenogeneic hepatocyte transplantation requires further validation. The potential of hepatocyte microencapsulation extends beyond the current scope of application, suggesting a promising horizon for liver failure treatment modalities. Innovations in encapsulation materials and techniques aim to enhance cell viability and function, indicating a need for comprehensive studies that bridge the gap between small-scale laboratory success and clinical applicability. Moreover, the integration of bioengineering and regenerative medicine offers novel pathways to refine hepatocyte transplantation, potentially overcoming the challenges of immune rejection and ensuring the long-term functionality of transplanted cells. In conclusion, while hepatocyte microencapsulation and transplantation herald a new era in liver failure therapy, significant strides must be made to translate these experimental approaches into viable clinical solutions. Future research should aim to expand the experimental models to include larger mammals, thereby providing a clearer understanding of the clinical potential of these therapies. Additionally, a deeper exploration into the mechanisms of cell survival and function within microcapsules, alongside the development of innovative encapsulation materials, will be critical in advancing the field and offering new hope to patients with liver failure.

Toxin-Induced Liver Injury and Extracorporeal Treatment of Liver Failure.

Poisoning with a large variety of drugs and naturally occurring toxins may result in acute liver injury and failure. Drug-induced liver injury is a major cause of liver failure nationwide, and it is likely that nephrologists will be involved in treating patients with these conditions. A number of xenobiotics resulting in liver toxicity may cause acute kidney injury or other organ injury as well. Most agents causing drug- or toxin-induced liver failure lack specific therapies, although a few xenobiotics such as acetaminophen have effective antidotal therapies if administered prior to development of hepatotoxicity. The nephrologist should be aware that extracorporeal treatment of liver failure associated with drugs and toxins may be indicated, including therapies conventionally performed by nephrologists (hemodialysis, continuous kidney replacement therapy), therapies occasionally performed by nephrologists and other specialists (plasma exchange, albumin dialysis, hemadsorption), and therapies performed by other specialists (extracorporeal membrane oxygenation). An overview of the role of these therapies in liver failure is provided, as well as a review of their limitations and potential complications.

Preclinical efficacy and safety of encapsulated proliferating human hepatocyte organoids in treating liver failure.

Alginate-encapsulated hepatocyte transplantation is a promising strategy to treat liver failure. However, its clinical application was impeded by the lack of primary human hepatocytes and difficulty in controlling their quality. We previously reported proliferating human hepatocytes (ProliHHs). Here, quality-controlled ProliHHs were produced in mass and engineered as liver organoids to improve their maturity. Encapsulated ProliHHs liver organoids (eLO) were intraperitoneally transplanted to treat liver failure animals. Notably, eLO treatment increased the survival of mice with post-hepatectomy liver failure (PHLF) and ameliorated hyperammonemia and hypoglycemia by providing liver functions. Additionally, eLO treatment protected the gut from PHLF-augmented permeability and normalized the increased serum endotoxin and inflammatory response, which facilitated liver regeneration. The therapeutic effect of eLO was additionally proved in acetaminophen-induced liver failure. Furthermore, we performed assessments of toxicity and biodistribution, demonstrating that eLO had no adverse effects on animals and remained non-tumorigenic.

The challenges and potential of microRNA-based therapy for patients with liver failure syndromes and hepatocellular carcinoma.

INTRODUCTION: Morbidity and mortality from liver disease continues to rise worldwide. There are currently limited curative treatments for patients with liver failure syndromes, encompassing acute liver failure and decompensated cirrhosis states, outside of transplantation. Whilst there have been improvements in therapeutic options for patients with hepatocellular carcinoma (HCC), there remain challenges necessitating novel therapeutic agents. microRNA have long been seen as potential therapeutic targets but there has been limited clinical translation. AREAS COVERED: We will discuss the limitations of conventional non-transplant management of patients with liver failure syndromes and HCC. We will provide an overview of microRNA and the challenges in developing and delivering microRNA-based therapeutic agents. We will finally provide an overview of microRNA-based therapeutic agents which have progressed to clinical trials. EXPERT OPINION: microRNA have great potential to be developed into therapeutic agents due to their association with critical biological processes which govern health and disease. Utilizing microRNA sponges to target multiple microRNA associated with specific biological processes may improve their therapeutic efficacy. However, there needs to be significant improvements in delivery systems to ensure the safe delivery of microRNA to target sites and minimize systemic distribution. This currently significantly impacts the clinical translation of microRNA-based therapeutic agents.

Severe jaundice with life-threatening liver failure after Kratom use: Reversed by plasma exchange.

Kratom is an herbal supplement which is used for its stimulating properties and pain reduction due to interaction with opioid receptors. Kratom overdose may cause fatality. A 56-year-old man was admitted to the emergency department with severe jaundice and liver failure. His total bilirubin reached at 70.6 mg/dL, but extensive workup did not show any liver mass. Family informed that the patient was taking Kratom. Plasma exchange was suggested as an unconventional therapy and consent from the patient was obtained because this procedure has never been performed to treat Kratom toxicity before. After four procedures, his total bilirubin was reduced to 23.9 mg/dL and his clinical condition improved significantly. Finally on day 5 he was discharged at stable condition with a total bilirubin value of 21.3 mg/dL. There is no antidote for Kratom, and treatment is supportive. To our knowledge this is the first report of reversing Kratom poisoning using plasma exchange.

3D Printing of a Vascularized Mini-Liver Based on the Size-Dependent Functional Enhancements of Cell Spheroids for Rescue of Liver Failure.

The emerging stem cell-derived hepatocyte-like cells (HLCs) are the alternative cell sources of hepatocytes for treatment of highly lethal acute liver failure (ALF). However, the hostile local environment and the immature cell differentiation may compromise their therapeutic efficacy. To this end, human adipose-derived mesenchymal stromal/stem cells (hASCs) are engineered into different-sized multicellular spheroids and co-cultured with 3D coaxially and hexagonally patterned human umbilical vein endothelial cells (HUVECs) in a liver lobule-like manner to enhance their hepatic differentiation efficiency. It is found that small-sized hASC spheroids, with a diameter of ≈50 µm, show superior pro-angiogenic effects and hepatic differentiation compared to the other counterparts. The size-dependent functional enhancements are mediated by the Wnt signaling pathway. Meanwhile, co-culture of hASCs with HUVECs, at a HUVECs/hASCs seeding density ratio of 2:1, distinctly promotes hepatic differentiation and vascularization both in vitro and in vivo, especially when endothelial cells are patterned into hollow hexagons. After subcutaneous implantation, the mini-liver, consisting of HLC spheroids and 3D-printed interconnected vasculatures, can effectively improve liver regeneration in two ALF animal models through amelioration of local oxidative stress and inflammation, reduction of liver necrosis, as well as increase of cell proliferation, thereby showing great promise for clinical translation.

Efficacy of therapeutic plasma exchange in pediatric cases of acute liver failure as an extracorporeal liver support system.

BACKGROUND: Acute liver failure in the pediatric population is often accompanied by deranged metabolism, severe encephalopathy and coagulopathy. A liver transplant is the most viable option for the management of such patients. Therapeutic plasma exchange (TPE) is helpful in improving the liver biochemistry profile, thereby, increasing their likelihood of undergoing a liver transplant METHOD: The study was conducted over a period of 3 years (January 2018 to December 2021). Indications mainly consisted of ALF with hepatic encephalopathy, worsening liver parameters in spite of medical management, and candidacy for undergoing a liver transplant. Plasma exchange was performed daily or alternatively until the patient recovered, succumbed, or was stable enough to undergo a transplant. Biochemical parameters serum bilirubin, ALT, AST serum ammonia serum urea, serum creatinine were recorded before and after TPE sessions. RESULTS: The study group comprised 14 patients of which a total of 28 TPE was performed. There were a total of 5 cases of cryptogenic ALF, 4 of Wilson disease, 2 cases each of infection-related ALF and autoimmune hepatitis, and a single case of drug-induced hepatitis. A total of 5 out of 14 patients underwent a liver transplant and amongst the 9 who did not undergo a transplant, 4 patients expired due to septic shock syndrome; the remaining 5 were discharged in a stable condition following TPE sessions. The disease-free survival was 78.9% and the transplant-free survival was 35.71%. CONCLUSION: TPE plays a crucial role in improving the biochemistry profile of the liver in children with liver failure.

[Research progress of non-biological artificial liver support system therapy for paitents with liver failure].

Liver failure progresses quickly with high mortality. Non-biological artificial liver support system therapy is one of the important treatments for patients with liver failure. The basic techniques of non-biological artificial liver support system therapy include plasma exchange, plasma adsorption and continuous renal replacement therapy. In this paper, the effect and choice of these basic techniques, the treatment timing, the possible patients who may benefit, and the existing problems are summarized and discussed. We hope to provide a reference for the rational use of non-biological artificial liver support system therapy in clinical practice.

Factors improving mortality in critically ill patients with liver failure - A systematic review.

Background: Acute and chronic hepatic failure can lead to increased mortality in critically ill and perioperative patients. Understanding the pathophysiological principles of these conditions in critically ill patients is of great importance to reduce mortality. The aim of our systematic literature review was to identify all randomized controlled trials on any intervention that had a statistically significant documented reduction in mortality in patients with hepatic failure. Methods: We searched PubMed, Scopus and Embase databases for pertinent studies on January 1st 2021. The following studies were included: randomized controlled trials; studies investigating adult critically ill or perioperative patient populations with any form of hepatic failure; mortality as primary or secondary outcome; and statistically significant differences in mortality between the examined groups. Results: We finally found nine trials in our systematic review on the effect of antibiotic administration and infectious diseases among patients with cirrhosis (three studies); immune modulation after liver transplantation (one study); administration of colloids in cirrhotic patients (one study); the effect of high-volume plasma exchange in acute liver failure (one study); administration of N-acetylcysteine in acute liver failure (one study); and treatment with terlipressin (two studies). Conclusion: In the present review we found only nine randomized studies with a documented survival benefit in patients with liver failure. Strategies that most improved mortality were associated with the outcome of sepsis and renal function.

Liver Support Techniques in Acute and Hyperacute Liver Failure.

With the growing prevalence of acute liver failure or acute-on-chronic liver failure, on the one hand, and the limited supply of liver organs for transplantation, on the other hand, it is critical to the design, validate, and implement devices that can provide extracorporeal liver support (ECLS) as the bridge to transplantation or potentially destination therapies. The number of attempts to generate ECLS devices has resulted in several options with various levels of impact on clinical outcomes. The described ECLS tools could be as simple as devices used for kidney replacement therapies (e.g., continuous kidney replacement therapy) to tools that employ albumin (e.g., Prometheus, single-pass albumin dialysis, or molecular adsorbent recirculating system), fresh frozen plasma (e.g., high-volume plasmapheresis), or hepatocytes (e.g., extracorporeal liver assist device with hepatocytes) to support failing liver functions, that is, metabolic or synthetic functions. This chapter describes the current landscape of ECLS devices and their associated evidence-based data.

Availability, Functionality, and Safety as well as Quality Control of Hepatocytes as Seeding Cells in Liver Regenerative Medicine: State of the Art and Challenges.

Hepatic disease is one of the most common causes of death worldwide and has become a global health problem. Liver transplantation is the only effective treatment strategy for patients with hepatic function failure, but the insufficient number of donated healthy livers is the main obstacle limiting this process. To alleviate the demand for donor's livers, alternative approaches are being actively explored using liver tissue engineering principles. Liver tissue engineering consists of three elements, including seeding cells, extracellular matrix, and bioreactors. Among them, seeding cell is the most key factor. In this regard, hepatocyte-based tissue engineering can overcome the above shortages for tissue repair and regeneration in hepatic disorders. Primary human hepatocytes in liver regenerative medicine are the most preferred seeding cells, although limited access to a sufficient number of functional hepatocytes are a major issue due to the difficulties in long-term function maintenance of hepatocyte as well as the lack of availability of healthy donors. Hepatocyte-like cells (HLCs), derived from various stem cells, including non-liver-derived stem cells and liver-derived stem cells, as well as trans-differentiation of other cell types, may provide adequate cell sources and could replace primary human hepatocytes as seeding cells. However, it is still a great difficulty that HLCs generated by stem cell differentiation meet the quality required for clinical therapy. Furthermore, none of the standardized protocols to generate high-quality HLCs is available. Whether primary hepatocytes or HLCs are from various sources, preventing the functional deterioration of hepatocytes or generating fully functional hepatocytes is also a big challenge, respectively. In addition, the adoptions of three-dimensional co-culture systems and some small-molecule compounds contribute to maintaining the hepatic functionality of primary hepatocytes and enhancing the liver-specific functions of HLCs. In short, hepatocyte-based liver regenerative medicine is an attractive alternative strategy for liver diseases, notwithstanding some challenges still exist from bench to bedside. This review summarizes the current status, issues, and challenges in availability, functionality, and safety, as well as quality control of seeding hepatocytes with regard to liver tissue engineering in regenerative medicine for the treatment of liver disorders.

Superior Dialytic Removal of Bilirubin and Bile Acids by Free Fatty Acid Displacement and Its Synergy With Albumin-Based Dialysis.

One of the cardinal features of any liver replacement therapy is the ability to remove accumulated metabolites. However, an unsolved problem is the low dialyzability of lipophilic toxins. This study aimed to explore whether bilirubin and bile acids removal can be increased by free fatty acid (FFA) displacement and its synergy with albumin dialysis. First, we found that the protein binding of both bilirubin and bile acids decreased significantly with increasing FFA concentrations when co-incubated directly. Then, in vitro dialysis showed that fatty acid mixtures infusion prefilter effectively increased the fractional removals of bilirubin and bile acids, showing higher efficiency compared with albumin-based hemodialysis (HD); in vivo dialysis in liver failure rats showed that lipid emulsion administration resulted in higher reduction ratios and more total solute removals for bilirubin and bile acids after 4 h HD compared with control, which were also superior to albumin-based HD. Finally, the highest dialysis efficacy was always observed by their synergy whether in vitro or in vivo . These findings highlight that FFA displacement-based HD could efficiently improve the dialytic removal of bilirubin and bile acids, which might even be more efficient than albumin-based HD. Their synergy may represent a promising strategy to maximize the removal of circulating bilirubin and bile acids accumulated in liver failure.

Successful use of single-pass albumin dialysis in the correction of severe hyperbilirubinemia in a case of acute hepatitis E.

INTRODUCTION: Acute liver failure (ALF) is a rare syndrome defined by the rapid loss of liver function in the absence of pre-existing liver disease, which may be secondary to hepatitis A virus, hepatitis E virus (HEV), or to drugs in about 50% of cases. Extracorporeal albumin dialysis enables the elimination of albumin-bound toxins that accumulate in liver failure. METHODS: We report a case of ALF secondary to HEV associated with severe hyperbilirubinemia. Patient was treated with four consecutive sessions of single-pass albumin dialysis (SPAD) carried out setting the following parameters: time: 300 min, Qb: 60 mL/min, Qd: 800-1000 mL/min, dialysate containing 4% albumin, citrate: 3-4 mmol/L. RESULT: SPAD documented good support of liver function. Bilirubin levels were reduced from 22 to 14 g/dL after four treatments. Pruritus was the first clinical sign of improvement. CONCLUSION: SPAD system can represent a safe and effective therapeutic option.