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.

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.

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.

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.

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.

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.

Construction of Kevlar nanofiber/graphene oxide composite beads as safe, self-anticoagulant, and highly efficient hemoperfusion adsorbents.

Recently emerged hemoperfusion absorbents, e.g. ion-exchange resin, activated carbon, and other porous materials, provide numerous novel possibilities to cure chronic liver failure (CLF) and renal failure (CRF). However, the limited adsorption performance and unsatisfactory blood compatibility significantly impede the development of the absorbents. Hence, designing safe and self-anticoagulant hemoperfusion absorbents with robust toxin clearance remains a considerable challenge. Here, brand new Kevlar-based composite gel beads for hemoperfusion are prepared by interface assembly based on π-π interaction. First, Kevlar nanofiber-graphene oxide (K-GO) beads are produced by liquid-liquid phase separation. Then, sodium p-styrenesulfonate (SS) is adsorbed onto the K-GO interface by π-π interaction and initiated to achieve the composite gel (K-GO/PSS) beads with an interfacial crosslinked structure. Such composite gel beads possess superior mechanical strength and self-anticoagulation capability, owing to the dual-network structure and heparin-mimicking gel structure, respectively. Furthermore, the K-GO/PSS beads show robust adsorption capacities for different kinds of toxins due to their strong charge and π-π interactions. A simulated hemoperfusion experiment in vitro demonstrates that the concentrations of the toxins in the blood can be restored to normal values within 30 minutes. In general, we envision that such composite gel beads will provide new strategies for future clinical CLF and CRF treatments.

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.

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.

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.

A graphene oxide-gold nanostar hybrid based-paper biosensor for label-free SERS detection of serum bilirubin for diagnosis of jaundice.

We report a paper-based surface-enhanced Raman spectroscopy (SERS) biosensor integrating the enrichment capability, namely enPSERS biosensor, for the sensitive, label-free detection of free bilirubin in blood serum for the accurate diagnosis of jaundice and its related diseases. This biosensor comprises multifunctional graphene oxide-plasmonic gold nanostar (GO-GNS) hybrids decorated on the filter paper, which integrates the high sensitivity of SERS detection, enrichment for serum bilirubin and fluorescence superquenching capability of GO-GNS hybrids for sensitive detection of serum bilirubin. The study of adsorption kinetics reveals that both electrostatic and π-π interactions between the GO-GNS hybrids and targets are responsible for the enrichment of bilirubin, and the adsorption process follows the pseudo-second-order kinetic model. The results of SERS detection of bilirubin in blood serum show two differential linear response ranges from 5.0 to 150 µM and 150-500 µM with the detection limit as low as 0.436 µM. The comparison of the results obtained from our present enPSERS biosensor with the commercial diazo reaction method for determination of free bilirubin in blood serum reveals the clinical effectiveness and suitability of the developed paper-based SERS biosensor. We believe that this sensitive and label-free SERS biosensor holds considerable promise for clinical translation in accurate diagnosis of jaundice.

Hemocompatible hemoadsorbent for effective removal of protein-bound toxin in serum.

Resin hemoperfusion is a life-saving treatment for drug intoxication or hepatic failure of patients. However, current resin adsorbents exhibit a limited hemocompatibility or low adsorption efficiency, representing a major roadblock to successful clinical applications. In this work, we developed a hemocompatible and effective hemoadsorbent based on polystyrene resin (H103) microparticles encapsulated in anti-biofouling zwitterionic poly(carboxybetaine) (PCB) hydrogels. Apart from a strong mechanical stability, this PCB-based adsorbent (PCB-H103) exhibited excellent hemocompatibility (hemolysis ratio was ∼0.64%), which was attributed to the anti-biofouling property of PCB hydrogel. In addition, it can efficiently adsorb both small and middle molecular weight molecules in phosphate-buffered saline, and the efficiencies were significantly higher than poly(ethylene glycol) methacrylate-based and poly(2-hydroxyethyl methacrylate)-based adsorbent counterparts, indicating the favorable permeability of PCB hydrogel coating. More importantly, PCB-H103 could effectively remove protein-bound toxins including phenol red and bilirubin in bovine serum albumin solution or even in 100% fetal bovine serum (FBS). In 100% FBS, the adsorption capacity of PCB-H103 towards bilirubin was 8.3 times higher than that of pristine clinical-scale resin beads. Findings in this work may provide a new strategy for the development of modern resin hemoperfusion technology.

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.

Sonochemical assisted synthesis of dual functional BSA nanoparticle for the removal of excessive bilirubin and strong anti-tumor effects.

In this study, we prepared a dual functional albumin-based nanoparticle (gal-BSA-NPs) by sonochemical method which allowed an efficient encapsulation for Bilirubin (BR) through its adsorption capacity and hydrophobic interaction. Our study provided a possibility that the blank gal-BSA-NPs can replace BSA with better ability for the adsorption of excessive BR. Additionally, we unearthed the potential anti-tumor activity of BR on HepG2 cells and developed GSH-responsive BR-loaded gal-BSA-NPs for the treatment of liver cancer. The results showed BR-loaded gal-BSA-NPs effectively enhanced cellular uptake and exerted strong inhibition on tumor cell proliferation and migration. In vivo anti-tumor study revealed BR-loaded gal-BSA-NPs showed strong anti-tumor effects. Our study not only revealed the anti-tumor potency of BR, but also brought conventional BSA with novel application in liver cancer treatment.

Fabrication of Organic Hec Nanocomposites Modified with Lysine as a Potential Adsorbent for Bilirubin Removal.

As one of the typical phyllosilicate clays, hectorite (Hec) has some excellent characteristics and has been greatly applied in adsorption field for the removal of dye, endotoxin, etc. In this study, organic Hec nanocomposites modified with L-Lysine (Lys/Hec NCs) were prepared via solution intercalation method for BR removal. The effects of ionic strength, pH values, initial concentration of BR, and BSA concentration on the adsorption capacity for BR of Lys/Hec NCs were investigated. Results indicated that the adsorption capacity for BR of nanocomposites could reach 40 mg/g when the initial bilirubin concentration was 200 mg/L. However, the adsorption amount of Lys/Hec NCs decreased with increasing the concentration of BSA, but Lys/Hec NCs could still maintain a higher adsorption rate. The adsorption kinetics and adsorption isotherms indicated that the adsorption process of Lys/Hec NCs agreed well with the pseudo-second-order model and the Langmuir isotherm, respectively. Moreover, Lys/Hec NCs also exhibited excellent cytocompatibility. These obtained results demonstrate that Lys/Hec NCs prepared in this study had great potential to be used in hemoperfusion.

High efficiency 3D nanofiber sponge for bilirubin removal used in hemoperfusion.

The accumulation of bilirubin in the body could cause nervous system diseases and even endanger life in severe cases for people with liver damage or metabolic obstruction. Hemoperfusion has been considered as one of the most efficient treatments to remove extra bilirubin. Although, the current bilirubin adsorbents could adsorb the free bilirubin effectively, the albumin-bound bilirubin in plasma is hard to remove. Here, we develop a 3D nanofiber sponge fabricated by combination of electrospinning and improved gas-foaming techniques. The amino groups and BSA molecules were immobilized on the fiber surface as the affinity groups to adsorb bilirubin. The 3D nanofiber sponges have layered structure and significantly higher porosity than two-dimensional nanofiber membranes. The special 3D structure renders the sponge fully contact with the adsorbed liquid and reduces the diffusion distance of the adsorbate, thus increases the sponge's adsorption rate. The BSA immobilized nanofiber sponge showed large adsorption capacity in both aqueous solution (maximum adsorption capacity was 36.8237 mg/g) and plasma (maximum adsorption capacity was 25.2908 mg/g), rapid adsorption rate (achieved adsorption equilibrium in 60 min) and well blood compatibility.

Poly-l-lysine modified cryogels for efficient bilirubin removal from human plasma.

In this study, poly-l-lysine (PLL) immobilized PHEMA cryogel was designed for the specific bilirubin removal from human plasma. The surface of PHEMA cryogels is surrounded by PLL chains to enhance specific binding of bilirubin molecules via specific complementary electrostatic interactions. The functionalization of the PHEMA cryogel was carried out by direct coupling of PLL to pre-activated OH-group of the HEMA alcohol units via carbodiimide activation. Prior to removal of bilirubin from human plasma, the optimization parameters including, initial bilirubin concentration, flow rate, temperature, ionic strength, and adsorption rates on adsorption of PLL-PHEMA cryogel were investigated from the aqueous medium. According to the elemental analyses results, the incorporation of PLL was 690.0 µmol/g cryogel. The cryogel has highly interconnected supermacroporous structure sized between 20 and 100 µm with a positive surface charge value. The maximum bilirubin adsorption capacity was found as 59.9 mg/g of the dry weight of PLL-PHEMA cryogel. Reusability study explored that PLL-PHEMA could be used with a negligible loss in the bilirubin adsorption capacity after successive ten adsorption-desorption cycles using the same adsorbent. The results of the study demonstrated that the PLL-PHEMA cryogel exhibited high specificity that can be used as an efficient column for removing the bilirubin from the human plasma.