Development of liposome as a novel adsorbent for artificial liver support system in liver failure.

Artificial liver support systems (ALSS), represented by albumin dialysis, are designed to replace the liver detoxification function and to serve as supportive therapy until liver transplantation or liver regeneration. We introduce liposome, which is majorly formed by soybean lecithin as the adsorbent nanomaterial in dialysate for the removal of protein-bound and liver failure-related solutes. The binding rate was detected by ultrafiltration column. In vitro and in vivo dialysis was performed in a recirculation system. Unconjugated bilirubin (52.83-99.87%) and bile salts (50.54-94.75%) were bound by liposomes (5-80 g/L) in a dose-response relationship. The in vitro haemodialysis model showed that the concentration of unconjugated bilirubin (45.64 ± 0.90 µmol/L vs. 54.47 ± 3.48 µmol/L, p < 0.05) and bile salts (153.75 ± 7.72 µmol/L vs. 180.72 ± 7.95 µmol/L, p < 0.05) were significantly decreased in the liposome dialysis group than in the phosphate buffer saline group. The in vivo haemodialysis model showed that 40 g/L liposome-containing dialysate led to a significant higher reduction ratio in total bilirubin (6.56 ± 5.72% vs. -1.86 ± 5.99%, p < 0.05) and more total bile acids (7.63 ± 5.27 µmol vs. 2.13 ± 2.32 µmol, p < 0.05) extracted in the dialysate in comparison with the conventional dialysate. In conclusion, the liposome-added dialysate proved to impose good extraction effects on the unconjugated bilirubin and bile salts. These findings indicate that conventional dialysate supported by this nanomaterial can markedly improve the removal of protein-bound and liver failure-related solutes, thus suggesting a novel and promising liver dialysis system.

A Gold Nanoclusters Film Supported on Polydopamine for Fluorescent Sensing of Free Bilirubin.

Serum bilirubin is an important biomarker for the diagnosis of various types of liver diseases and blood disorders. A polydopamine/gold nanoclusters composite film was fabricated for the fluorescent sensing of free bilirubin. Bovine serum albumin (BSA)-stabilized gold nanoclusters (AuNCs) were used as probes for biorecognition. The polydopamine film was utilized as an adhesion layer for immobilization of AuNCs. When the composite film was exposed to free bilirubin, due to the complex that was formed between BSA and free bilirubin, the fluorescence intensity of the composite film was gradually weakened as the bilirubin concentration increased. The fluorescence quenching ratio (F0/F) was linearly proportional to free bilirubin over the concentration range of 0.8~50 µmol/L with a limit of detection of 0.61 ± 0.12 µmol/L (S/N = 3). The response was quick, the film was recyclable, and common ingredients in human serum did not interfere with the detection of free bilirubin.

Therapeutic plasma exchange versus double plasma molecular absorption system in hepatitis B virus-infected acute-on-chronic liver failure treated by entercavir: A prospective study.

BACKGROUND: Therapeutic plasma exchange (TPE) and double plasma molecular absorption system (DPMAS) were two extracorporeal liver support systems. Few studies compared their efficacy profile. OBJECTIVE: This study was to compare the efficacy of TPE and DPMAS on acute-on-chronic liver failure (ACLF) caused by hepatitis B virus (HBV-ACLF). METHODS: 60 HBV-ACLF patients were enrolled and prospectively studied. All patients received entecavir therapy, and were assigned to TPE group (n = 33) and DPMAS group (n = 27). Primary end-points were the effects of TPE and DPMAS on liver function and serum inflammatory markers. RESULTS: Serum procalcitonin, interleukin (IL)-6, and high sensitive C-reactive protein (hsCRP) were significantly elevated in patients with HBV-ACLF. TPE achieved significantly higher removal rates of total bilirubin (TBIL, P = .002), direct bilirubin (DBIL, P = .006), and hsCRP (P = .010) than DPMAS, but DPMAS displayed lower loss rate of albumin (P = .000). TPE and DPMAS resulted in similarly increased serum IL-6 levels and comparable 12-week survivals (P > .05). Multivariate analysis showed that hospital stay (Relative Risk [RR]: 1.062, 95% Confidence Interval [CI]: 1.011-1.115, P = .016), prothrombin time (RR: 1.346, 95% CI: 1.077-1.726, P = .010), and international normalized ratio (RR: 0.013, 95% CI: 0.006-0.788, P = .041) were independent predictors for 12-week survival. Both TPE and DPMAS treatments were well-tolerated. CONCLUSION: Compared to DPMAS, TPE was more efficient in eliminating TBIL, DBIL, and hsCRP, but it was associated with higher loss rate of albumin. TPE and DPMAS were similar in improving 12-week survivals in HBV-ACLF.

Functionalized Magnetic Fe3O4-ß-Cyclodextran Nanoparticles for Efficient Removal of Bilirubin.

Bilirubin (BR), as a lipophilic toxin, can binds and deposits in various tissues, especially the brain tissue, leading to hepatic coma and even death. Magnetic nanoparticles adsorbent modified by ß-cyclodextran (Fe3O4-ß-CD) was developed to remove the BR from the plasma. Fe3O4-ß-CD nanoparticles was prepared through Schiff base reaction between the polyethylenimine (PEI)-modified Fe3O4 and aldehyde-functionalized ß-CD, and characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and dynamic light scattering (DLS). Under optimized conditions, the Fe3O4-ß-CD adsorbent could adsorb 225.6 mg/g free BR in PBS and reach the adsorption equilibrium within 90 min mainly through hydrophobic interaction; Moreover, the adsorbent displayed better adsorption capability in a dialysis system for BSA-bound bilirubin, plasma bilirubin and total bile acid, and the removal rates of those were 66%, 31% and 41% respectively. Because of the advantages of fast separation and purification process, low preparation cost, good adsorption capability for plasma bilirubin, Fe3O4-ß-CD may become an economical and promising absorbent of BR for clinical applications.

Preparation and Adsorption Properties of Novel Porous Microspheres with Different Concentrations of Bilirubin.

BACKGROUND: Plasma perfusion was widely used to clear toxic substances of plasma. Particle size and uniformity of adsorbent microspheres also affect the absorption rate. METHODS: Conventional suspension polymerization was improved using a pre-dispersion homogenizer to obtain novel adsorbent microspheres, named ERM-0100. Microsphere-related characteristics and attributes were analysed. RESULT: The ERM-0100 microspheres efficiently adsorbed different bilirubin concentrations, with a maximum rate of 59.72 ± 1.08%. At high bilirubin concentrations, ERM-0100 exhibited similar adsorption rate with BRS350 and BS330 (p = 0.303, p = 1.000, relatively), and higher than HB-H-6 (p = 0.000). At different concentration, ERM-0100 showed good adsorption performance. The ERM-0100 had no significant adsorption for electrolyte; for TP and ALB, the loss rates of ERM-0100 were 15.65 ± 0.36 and 23.23 ± 1.11%, respectively. In addition, ERM-0100 showed good blood compatibility. CONCLUSION: The ERM-0100 is a potential biomedical material for plasma perfusion for good effect, less costs and more safety. The microspheres may be coated to reduce its protein adsorption.

Functional polyethersulfone particles for the removal of bilirubin.

In this study, polyethersulfone/poly (glycidyl methacrylate) particles are prepared via in situ cross-linked polymerization coupled with a phase inversion technique. The surfaces of these particles are then further modified by grafting amino groups using tetraethylenepentamine, dethylenetriamine, ethylenediamine, or 1,6-hexanediamine for the removal of bilirubin. The particles are characterized by Flourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Batch adsorption experiments are performed to verify the adsorption capability, and the effect of bilirubin initial concentration, bovine serum albumin concentration, and solution ionic strength on the adsorption is also investigated. In addition, both adsorption kinetic and isotherm models are applied to analyze the adsorption process of bilirubin, and a particle column is used to further study the bilirubin removal ability.To prove that the method was a universal portal to prepare functional particles, polysulfone, polystyrene, and poly(vinylidene fluoride) based functional particles were also prepared and used for the removal of bilirubin. This study and the results indicated that the particles had a great potential to be used in hemoperfusion treatment for hyperbilirubinemia.

Preparing high-performance microspheres based on the chitosan-assisted dispersion of reduced graphene oxide in aqueous solution for bilirubin removal.

The removal of excess bilirubin from blood is of great clinical importance. Reduced graphene oxide (rGO) is often used to efficiently remove bilirubin. However, thin rGO pieces tend to aggregate in the aqueous phase because they are hydrophobic. In this context, we propose an effective strategy based on the chitosan-assisted (CS-assisted) dispersion of rGO to produce high-performance bilirubin-adsorbing microspheres. CS possesses a hydrophobic CH structure, which offers strong hydrophobic interactions with rGO that assist its dispersion, and the large number of hydrophilic sites of CS increases the hydrophilicity of rGO. CS serves as a dispersant in a surfactant-like manner to achieve a homogeneous and stable CS/rGO dispersion by simply and gently stirring CS and rGO in a LiOH/KOH/urea/H2O system. Subsequently, CS/rGO hybrid microspheres were prepared by emulsification. CS ensures blood compatibility as a base material, and the entrapped rGO contributes to mechanical strength and a high adsorption capacity. The CS/rGO microspheres exhibited a high bilirubin adsorption capacity (215.56 mg/g), which is significantly higher than those of the rGO and CS microspheres. The determined mass-transfer factors revealed that the rich pores of the CS/rGO microspheres promote mass transfer during bilirubin adsorption (equilibrium is almost achieved within 30 min). The CS/rGO microspheres are promising candidates for bilirubin removal owing to a combination of high strength, blood compatibility, and high adsorption capacity.

Compact photometric detector integrated with separation microchip for potential portable liquid chromatography system.

In recent years, miniaturized analytical instruments have been developing to meet the needs of portable and rapid analysis. The key of miniaturized analytical equipment is the miniaturization and integration of functional modules. This paper aims to develop a miniaturized photometric detector and separation microfluidic chip for a liquid chromatography (LC) system. The detector uses a light-emitting diode to emit ultraviolet light, which is collimated by an internal double lens. A Z-shaped flow cell with a long optical path is designed and fabricated in the separation microfluidic chip with a three-layer structure, which provides a tubing-free connection between the separation and detection unit. Detector performance is evaluated using hemoglobin (Hb) samples, with an upper limit of detection linearity (95 %) of 0.345 AU and stray light level as low as 0.08 %. Additionally, the microchip channel can be filled with cation exchange resin and C18 particles. Finally, an ion LC system and a reversed-phase LC system were constructed based on the miniaturized photometric detector and two microchips with different packed columns, respectively, and were successfully used in the separation and detection of two metabolic markers (glycated hemoglobin or bilirubin). The results of this study are expected to facilitate the development of a portable LC system and their application in community health services and family health management of chronic diseases.

Water-soluble adsorbent ß-cyclodextrin-grafted polyethyleneimine for removing bilirubin from plasma.

A water-soluble adsorbent was developed for removing bilirubin from the plasma of hyperbilirubinemia patient. The adsorbent was synthesized by grafting ß-cyclodextrin (ß-CD) to branched polyethyleneimine (PEI) matrix. The resulting ß-CD-PEI polymer had an average molecular weight of 163.7 kD, and it contained 56.3 ß-CD functional groups. In ß-CD-PEI-spiked dialysis, 35.8% of plasma bilirubin was removed, which was higher than that removed by the same concentration of bovine serum albumin. ß-CD-PEI also removed aromatic amino acids and bile acids. The results indicated that ß-CD-PEI could be an effective adsorbent for blood purification application aiming at the removal of toxins.

Clearing of toxic substances: are there differences between the available liver support devices?

Toxins accumulating in liver failure split into water solved (e.g. ammonia) and albumin bound substances (e.g. bilirubin). Because the latter cannot be removed by conventional haemodialysis, special liver support systems have been developed. The majority of data concerning elimination efficiency exist for the cell-free devices Molecular Adsorbent Recirculating System (MARS) and Prometheus, as they have been commercially available in Europe since many years. Overall, Prometheus provides higher clearances for most liver toxins, especially if they are tightly albumin bound. However, for bile acids and cytokines no such differences could be found. Single pass albumin dialysis (SPAD) can be assumed to be equally effective as MARS. None of the bioartificial liver support systems being developed is on the market today and published clearance data are scarce. In general, clearance efficiency for albumin bound substances is relatively low in all systems currently available. Besides optimizing biocompatibility and selectivity, future technologies should also focus on improved detoxification efficiency of liver support devices.

Hierarchical core-shell nanoplatforms constructed from Fe3O4@C and metal-organic frameworks with excellent bilirubin removal performance.

Hemoperfusion has become the third-generation treatment strategy for patients suffering from hyperbilirubinemia, but adsorbents used for bilirubin removal mostly face intractable problems, such as unsatisfactory adsorption performance and poor hemocompatibility. Metal-organic frameworks (MOFs) are promising adsorbents for hemoperfusion due to their high specific surface areas and easily modified organic ligands. However, their microporous properties and separation have hampered their application. Here, a novel hierarchical core-shell nanoplatform (named Double-PEG) with tailored binding sites and pore sizes based on Fe3O4@C and Uio66-NH2 was constructed. Notably, Double-PEG showed excellent bilirubin uptake of up to 1738.30 mg g-1 and maintained excellent bilirubin removal efficiency in simulated biological solutions. A study on the adsorption mechanism showed that the adsorption of Double-PEG towards bilirubin tended to be chemical adsorption and in accordance with the Langmuir model. Besides, the good separability, recyclability, cytotoxicity and hemocompatibility of Double-PEG show great potential in hemoperfusion therapy. The finding of this study may provide a novel insight into the application of MOF materials in the field of hemoperfusion.

Successful elimination of bilirubin in critically ill patients with acute liver dysfunction using a cytokine adsorber and albumin dialysis: a pilot study.

There are different methods of artificial liver support for patients with acute liver dysfunction (ALD). However, CytoSorb (CS) might be a new approved option for those patients. Question of interest is whether the elimination performance of CS was comparable to that of advanced organ support (ADVOS). Patients, treated with CS (integrated into high-flux dialysis) or ADVOS and a total bilirubin > 10 mg/dl were included. Laboratory parameters were evaluated before starting therapy (d0) and 12-24 h thereafter (d1). The Wilcoxon-test with associated samples was used for statistical analysis. Thirty-nine patients (33 CS, 6 ADVOS) were included. The median bilirubin at d0 was 16.9 and 17.7 mg/dl and at d1 was 13.2 and 15.9 mg/dl, in the CS and ADVOS group, respectively. There was a significant bilirubin reduction as well in the CS group (p < 0.001, median relative reduction: 22.5%) as in the ADVOS group (p = 0.028, median relative reduction: 22.8%). There was no significant difference in the relative bilirubin reduction between CS and ADVOS therapies. The use of CytoSorb and ADVOS in patients with ALD led to a significant and comparable decrease in total bilirubin. The easy use of CS might be an advantage compared to other procedures.

Impact of anion exchange adsorbents on regional citrate anticoagulation.

INTRODUCTION: Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations. METHODS: Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption. RESULTS: Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment. CONCLUSIONS: The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

Prognostic significance of pre-treatment ALBI grade in advanced non-small cell lung cancer receiving immune checkpoint therapy.

The liver is an essential organ for regulating innate and acquired immunity. We hypothesized that the pre-treatment hepatic function affects the clinical outcome of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC). We analyzed 140 patients with NSCLC who received ICIs. We investigated the association between pre-treatment liver function, assessed using the albumin-bilirubin (ALBI) grade, and clinical outcomes in univariate, multivariate, and propensity score matching analyses. Patients were divided into four grades according to pre-treatment liver function. Eighty-eight patients had good hepatic reserve (ALBI grade 1 or 2a), whereas 52 patients had poor hepatic reserve (ALBI grade 2b or 3). In the univariate Kaplan-Meier analysis, the ALBI grade 1, 2a group had a significantly prolonged progression-free survival (PFS, 5.3 versus 2.5 months, p = 0.0019) and overall survival (OS, 19.6 vs. 6.2 months, p = 0.0002). These results were consistent, regardless of whether the analysis was performed in patients with a performance status of 0 or 1 at pre-treatment (N = 124) or in those selected using propensity score matching (N = 76). In the multivariate analysis, pre-treatment ALBI grade was an independent prognostic factor for both PFS (hazard ratio [HR] 0.57, 95% confidence interval [95% CI] 0.38-0.86, p = 0.007) and OS (HR 0.45, 95% CI 0.29-0.72, p = 0.001). Our results suggest that pre-treatment hepatic function assessed by ALBI grade could be an essential biomarker for predicting the efficacy of treatment with ICIs in NSCLC.

Polydopamine decorated ordered mesoporous carbon for efficient removal of bilirubin under albumin-rich conditions.

Excess bilirubin in the body will lead to serious health problems; however, its efficient removal remains a challenge in the clinical field because the available sorbent materials still suffer from serious performance issues, performance declining in a high-content albumin environment. Herein, we prepared a novel polydopamine (PDA) decorated ordered mesoporous carbon (OMC) material for the efficient removal of bilirubin in albumin-rich conditions. OMC was used as the supporting material due to its high specific surface area and its good affinity to hydrophobic analytes. PDA was then decorated on the OMC material through a facile self-assembly process to form a surface-imprinted layer. The obtained PDA-coated OMC material (OMC@PDA) exhibited excellent adsorption performance towards bilirubin in albumin-free conditions, in which its theoretical maximum adsorption amount was calculated to be 513.54 mg g-1. The imprinted PDA layer, for which the association constant towards bilirubin reached 4.51 × 104 M-1, endowed OMC@PDA with a competitive affinity compared to albumin. Therefore the materials showed good adsorption capacity and efficiency even in an albumin-rich environment (the adsorption equilibrated at 122.7 mg g-1 in 30 min). In addition, the good biocompatibility of OMC@PDA was demonstrated by hemolysis assay and protein fouling evaluation, which indicated the feasibility of applying this material in clinical situations.

Amides and Heparin-Like Polymer Co-Functionalized Graphene Oxide Based Core @ Polyethersulfone Based Shell Beads for Bilirubin Adsorption.

Excessive bilirubin in the body of patient with liver dysfunction or metabolic obstruction may cause jaundice with irreversible brain damage, and new type of adsorbent for bilirubin is under frequent investigation. Herein, graphene oxide based core @ polyethersulfone-based shell beads are fabricated by phase inversion method, amides and heparin-like polymer are introduced to functionalize the core-shell beads. The beads are successfully prepared with obvious core-shell structure, adequate thermostability and porous shell. Clotting times and protein adsorption are investigated to inspect the hemocompatibility property of the beads. The adsorption of bilirubin is systematically investigated by evaluating the effects of contacting time, initial concentration and temperature on the adsorption, which exhibits improved bilirubin adsorption amount for the beads with amides contained cores or/and shells. It is worth believing that the amides and heparin-like polymer co-functionalized core-shell beads may be utilized in the field of hemoperfusion for bilirubin adsorption.

High-strength, blood-compatible, and high-capacity bilirubin adsorbent based on cellulose-assisted high-quality dispersion of carbon nanotubes.

Excess bilirubin can accumulate in body organs and has serious effects on human health. In this work, a simple engineering strategy, based on cellulose-assisted high-quality dispersion of carbon nanotubes (CNTs), is proposed to produce high-performance bilirubin adsorbents. By dispersing cellulose and CNTs in NaOH/thiourea aqueous solution, a homogeneous and stable cellulose/CNTs solution is achieved. The obtained cellulose/CNTs solution is applied for the fabrication of cellulose/CNTs microspheres (CCMs), in which cellulose serves as a base material and guarantees the blood compatibility of the composite material, and CNTs contribute to the improved mechanical strength and high adsorption capacity. To further improve blood compatibility and adsorption capacity, lysine is immobilized on the CCMs. The obtained lysine-modified CCMs (LCCMs) exhibit a large surface area (171.31 m2/g) and hierarchically porous structure. Experimental results demonstrate LCCMs have high bilirubin adsorption capacity (204.12 mg/g) that is significantly higher than most of the reported adsorbents. The combination of high strength, blood compatibility, and high adsorption capacity positions the LCCMs as a promising candidate for bilirubin removal.

Fabrication of chitosan/graphene oxide composite aerogel microspheres with high bilirubin removal performance.

Functional chitosan/graphene oxide (CS/GO) composite aerogel microspheres were fabricated via CO2 supercritical drying, which displayed excellent performance for bilirubin removal. The morphology and chemical structure of CS/GO composite aerogel microspheres were characterized, which illustrated a nanoporous structure with a maximum specific surface area of 174.69 m2/g, and a special pore size distribution at 20-40 nm, also a good mechanical property. Importantly, the composite aerogel microspheres (10% GO) revealed a large adsorption capacity (178.25 mg/g) for bilirubin within 2 h. Dynamic adsorption experiment illustrated that the aerogel microspheres adsorbed much more bilirubin with a shorter equilibrium time of about 30 min. Besides, the adsorption mechanism of bilirubin by the CS/GO composite aerogel microspheres was investigated through the relevant model fitting, including adsorption kinetics and adsorption isotherm, which illustrated that the mechanism included both physical and chemical processes, but chemical adsorption was dominated. Adsorption isotherm indicated that bilirubin adsorption by the microspheres was fitted well with Freundlich isotherm, which ascribed to multilayer adsorption. After five adsorption-desorption cycles, the adsorption capacity still maintains large adsorption capacity. In addition, the hemolysis rate and coagulation time tests presented the good blood compatibility for the adsorbents. Therefore, the CS/GO composite aerogel microspheres with rapid, high adsorption capacity and good blood compatibility might be promising for hyperbilirubinemia treatment.

Metal-Organic Framework Traps with Record-High Bilirubin Removal Capacity for Hemoperfusion Therapy.

Adsorption-based hemoperfusion has been widely used to remove toxins from the blood of patients suffering acute liver failure (ALF). However, its detoxification effect has been severely hampered by the unsatisfactory adsorption performance of clinically used porous adsorbents, such as activated carbon (AC) and adsorption resin. Herein, two cage-based metal-organic frameworks (MOFs), PCN-333 (constructed from 4,4,4-s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB) ligands and Al3 metal clusters) and MOF-808 (constructed from 1,3,5-benzenetricarboxylic acid (H3BTC) ligands and Zr6 metal clusters), are introduced for highly efficient hemoperfusion. They possess negligible hemolytic activity and can act as "bilirubin traps" to achieve outstanding adsorption performance toward bilirubin, a typical toxin related to ALF. Notably, PCN-333 shows a record-high adsorption capacity (∼1003.8 mg g-1) among various bilirubin adsorbents previously reported. More importantly, they can efficiently adsorb bilirubin in bovine serum albumin (BSA) solution or even in 100% fetal bovine serum (FBS) due to their high selectivity. Strikingly, the adsorption rate and capacity of PCN-333 in biological solutions are approximately four times faster and 69 times higher than those of clinical AC, respectively. Findings in this work pave a new avenue to overcome the challenge of low adsorption efficiency and capacity in hemoperfusion therapy.