Dialysis Membrane Research Articles

Effect of an Online Hemodiafiltration (OL-HDF) Session in Children with Chronic Kidney Disease Stage 5 on Circulating Neutrophil Extracellular Traps (NETs)

Abstract Background Conventional Hemodialysis (HD) process can trigger inflammation and induce cytokines activation. Neutrophils extrude neutrophil extracellular traps (NETs) which are extracellular chromatin containing a variety of granular proteins that have been implicated in infection, as well as vascular inflammation and occlusion. Hence reducing HD induced neutrophil activation has the potential benefit of ameliorating both acute and chronic inflammatory conditions in CKD patients. Strategies to achieve this goal aim at having more biocompatible dialyzer membrane polymers and sterilization techniques and more efficient new dialysis modalities like online hemodiafiltration (OL-HDF). To our knowledge the effect of OL-HDF on neutrophil activation in children with chronic kidney disease stage 5 on dialysis (CKD-5d) has not been studied. Objective To assess the effect of a single OL-HDF session on the level of circulating NETs in children with CKD-5d. Methods This is a cross sectional study done at Pediatric Dialysis Unit (PDU), Children’s Hospital, Ain Shams University during the period from March 2023 to July 2023. It included 30 CKD-5d cases on OL-HDF for 3 months. All patients were receiving 3 sessions weekly with a 3-hour duration per session. Thirty age and sex matched healthy children were also enrolled as controls. Patients with the following medical conditions were excluded: failed renal graft, active infection, autoimmune disease, active thrombosis, diabetes mellitus, malignancy, cardiovascular disease like (infective endocarditis, vegetation and intracardiac mass) and patients on immunosuppressants. Complete blood cell (CBC), C-reactive protein (CRP) and serum NETs measured by ELISA were done for all cases pre- and post-OL-HDF as well as for the controls. Results The mean age of the cases was 12.2±2.8 years. They were 17 males (56.7%) and 13 females (43.3%). The mean age of the controls was 10.9±2.7 years. They were 15 males (50%) and 15 females (50%). Cases and controls were matched for age (p = 0.12) and sex distribution (p = 0.80). There was significantly elevated pre-OL-HDF (960.42 ± 498.55ng/L) and post-OL-HDF (213.98 ± 84.60ng/L) serum NETs compared to its level (147.12 ± 51.73ng/L) in controls (p < 0.001 for both). There was also significantly lower post-OL- HDF level of serum NETs than its pre-OL-HDF one (p < 0.001). There was no significant difference in circulating NETs between males and females (p = 0.19). Neither pre-OL_HDF nor post-OL-HDF serum NETS levels had any significant correlation with patients’ age (r = 0.051, p = 0.80) or pump blood flow rate (rho=-0.02, p = 0.91) respectively. In addition, there was no significant correlation between serum NETs and total leukocyte count (r = 0.37, p = 0.07; r = 0.14, p = 0.50), absolute neutrophil count (rho=0.40, p = 0.05; r = 0.055, p = 0.79) and absolutes lymphocyte count (r = 0.10, p = 0.65; r = 0.22, p = 0.30) for pre-OL-HDF and post-OL-HDF measures respectively. Conclusion There was significant statistical evidence of reduction in circulating NETs following an OL-HDF session in children with CKD-5d. Despite this reduction, the post- OL-HDF level of circulating NETs was still significantly higher than controls. This means that OL-HDF ameliorates the inflammatory milieu in CKD-5d children.

Increased Dialyzer Membrane Hydrophilicity Improves Hemocompatibility and Performance: A Randomized Investigation

Increased Dialyzer Membrane Hydrophilicity Improves Hemocompatibility and Performance: A Randomized Investigation

Intradialytic Microvascular Tissue Perfusion Is Affected by Dialyzer Membrane Characteristics

Intradialytic Microvascular Tissue Perfusion Is Affected by Dialyzer Membrane Characteristics

Development of Nanostructured Lipid Carriers for Donepezil Hydrochloride Effective Nose to Brain Delivery

ABSTRACT: This study focuses on the development and evaluation of nanostructured lipid carriers (NLCs) for the efficient intranasal delivery of donepezil hydrochloride. The NLCs were prepared using the microemulsion technique. Each excipient used in the formulation was thoroughly evaluated for stability, assessing factors such as color change, phase separation, precipitation, and texture. Characterization of the NLCs included the construction of a pure calibration curve, differential scanning calorimetry (DSC), infrared spectroscopy (IR), and the IR analysis of physical mixtures. The donepezil hydrochloride-loaded NLCs were then incorporated into a thermosensitive gel using Pluronic F127, which was also prepared using the microemulsion technique. The NLCs were further characterized by evaluating their zeta potential, entrapment efficiency, and particle size. The thermosensitive gel's properties were assessed by measuring the gelation temperature and viscosity. Drug release studies were conducted using a dialysis membrane to compare the release profiles of the pure drug, donepezil-HCl-loaded NLCs, and the NLC-loaded thermosensitive gel, focusing on their potential for controlled drug release.

Graphene-Based Nano Drug Delivery of Curcumin for the Treatment of Dengue Fever.

Graphene, which is defined as a single-layered sp2 hybridized carbon atoms placed in a honeycomb-like crystal lattice when converted to graphene oxide, has proven its worth by showing its tremendous capacity in controlling the release rate of drugs by entrapping in the numerous pockets present inside it through π-π stacking interaction when used as a nanocarrier. In this experiment graphene oxide was synthesized through traditional Hummer’s method and was used as a nanocarrier to target nanosized drugs, which was prepared by loading curcumin drug into the PVP functionalized graphene oxide by using necessary procedures. After the successful confirmation of the stability, functionalization, and compatibility through various characterization procedures and effective drug loading into the systems, the release behavior of the formulations has been checked through dialysis bag diffusion technique using potassium phosphate buffer saline (pH 7.2, 4.0 and 9.2) for selection of the best medium for determination of the successful sustained-release behavior of the drugs through the dialysis membrane which concluded with satisfactory, sustained and constant drug release phenomenon in the acidic environment reflecting an idea of the fact its favorable release in acidic pH. It is a fact known that dengue fever causes systemic acidosis i.e., reduction of the pH of blood below 7. Thus, when used in-vivo there is a possibility that the formulation has easy access to its target and, performs the desired mechanism of action and can be used as a therapeutic delivery system against the Dengue virus.

Real-Time Dialysis Dose: Ionic Dialysis Versus Classical Urea Kinetic Modeling Indices.

Introduction Worldwide, over 850 million people need renal replacement therapy, and over 80% of them are on hemodialysis. The term "dialysis adequacy" is most often associated with the achievement of minimally acceptable indices - single pool Kt/V (spKt/V) and urea reduction ratio (URR%) and largely does not take into account other clinical indicators in patients. In addition, it should be taken into account that in the conditions of clinical practice, their measurement is carried out according to standards controlled by the regulatory structures and is carried out with a frequency between one and three months, and not during each dialysis procedure. Accordingly, based on the obtained value, we assume that it refers to the urea clearance of the entire dialysis prescription. A new methodology for measuring dialysis adequacy through ionic dialysis allows dose estimation in real time without the need for additional blood testsby recording the difference in sodium ion conductivity at the dialyzer inlet and outlet. The latter corresponds to the dialysis dose delivered and can be measured at each dialysis session, enabling timely therapeutic intervention at minimal cost to the community. The aim of this original article is to present ion dialysis to the community as a reliable and inexpensive alternative to classical urea kinetic modeling (UKM), evaluating the comparability of the two methods and the possible sources of error in the result. Material and methods This was a retrospective study of 32 patients undergoing hemodialysis at the Clinic of Nephrology and Dialysis at the University Hospital St. Marina (Varna, Bulgaria) for the period between January and December 2020.For each of the patients, four measurements (every three months) of the delivered dialysis dose were performed by ion dialysis and classical urea kinetic modeling in order to assess the comparability and reliability of the two methods. Results The analysis of the results proved a high correlation between the validated indicators of dialysis adequacy (spKt/V; URR) and those registered with online monitoring (online clearance monitor) by ionic dialysis - online Kt/V (onKt/V)while at the same time reporting a significant difference in the two methods - primarily based on the anthropometric formulas used to estimate the volume. The established regression models confirmed the high predictive value of ionic dialysis in relation to the actually delivered dose. Discussion Despite the high bond strength, our recorded values ​​for onKt/V are 8% lower compared to results using UKM. Therefore, onKt/V as an assessment metric has the ability to underestimate the dialysis dose received. Various factors as a possible source of error and its cause have been reported by some authors. Several studies have reported differences of 2-5% in instantaneous conductance measurements, which they associate mainly with differences in the diffusion coefficients of urea and sodium, as well as different effects of dialysis membrane charge or inadequate ultrafiltration correction. Conclusions Our study confirms that online clearance monitoring (OCM) is a practical non-invasive tool for daily use that complements the classic performance of OCM by helping to deliver an adequate dialysis dose with increased patient benefit and minimal cost of financial resources.

Depurative capacity toward medium molecules of the dialyzer Toray NV-U® Hydrolink™: A new hydrophilic membrane to perform online hemodiafiltration.

New dialysis membranes with new properties are being developed to improve efficacy and tolerance. The hemocompatibility of a polymeric biomaterial is influenced by the layer of water at the blood membrane interface. The new dialyzer TORAY NV-U® has a membrane Hydrolink™, designed to suppress platelet adhesion and to improve the hemocompatibility. Until now, there is no experience in online hemodiafiltration (OL-HDF).The objective of the present study is to evaluate the efficacy of this new membrane in OL-HDF therapy compared to another membrane commonly used. Other objectives are to evaluate the inflammatory response, hemodynamic tolerance, and the anticoagulation regimes. This is a prospective pilot study performed in five anuric patients receiving OL-HDF. For 1 month patients were kept with their usual dialyzer FX1000® (FMC). Subsequently, the dialyzer was changed to TORAY NV-U® (Hydrolink®) for 1 month. In the last dialysis session of each dialyzer, blood tests were performed to evaluate inflammation and depurative capacity. We did not find differences in medium size removal molecules and convective volume: FX1000®: 31 ± 9 l per session and Hydrolink™ 30 ± 8 l; p = 0.7); β2microglobulin reduction ratio (RR) FX1000® FMC 83 ± 3%; Hydrolink™ 79 ± 4; p = 0.14; Myoglobin RR FX1000® FMC 72 ± 7%; Hydrolink™ 76 ± 4; p = 0.28. We did not find differences in inflammation parameters: serum IL6 with FX1000® 6.0 ± 4.2 pg/mL; Hydrolink™ 7.6 ± 5.0 pg/mL; p = 0.3.During all sessions with the two dialyzers there was adequate plasmatic filling, reaching 85 % filling. All patients had "good" dialyzer status in all dialysis sessions with TORAY NV-U®, while the dialyzer status with FX1000® was "good" in 20% of the sessions, "medium" in 30%, and "dirty" in the remaining 50% dialysis sessions. The new dialyzer Hydrolink™, TORAY NV-U® is not inferior to perform OL-HDF compared to dialyzers usually used for this therapy, and could allow decrease heparin doses. Further studies with a bigger sample size and longer follow-up will answer if Hydrolink improves inflammation and assess a better hemodynamic tolerance.

In situ estimation of phytoplankton community growth rate inside dialysis membrane bags: a bioassay experiment at a fish farm in the eastern Aegean Sea

In situ estimation of phytoplankton community growth rate inside dialysis membrane bags: a bioassay experiment at a fish farm in the eastern Aegean Sea

Acquisition of elemental sulfur by sulfur-oxidising Sulfolobales.

Elemental sulfur (S8 0)-oxidising Sulfolobales (Archaea) dominate high-temperature acidic hot springs (>80°C, pH <4). However, genomic analyses of S8 0-oxidising members of the Sulfolobales reveal a patchy distribution of genes encoding sulfur oxygenase reductase (SOR), an S8 0 disproportionating enzyme attributed to S8 0 oxidation. Here, we report the S8 0-dependent growth of two Sulfolobales strains previously isolated from acidic hot springs in Yellowstone National Park, one of which associated with bulk S8 0 during growth and one that did not. The genomes of each strain encoded different sulfur metabolism enzymes, with only one encoding SOR. Dialysis membrane experiments showed that direct contact is not required for S8 0 oxidation in the SOR-encoding strain. This is attributed to the generation of hydrogen sulfide (H2S) from S8 0 disproportionation that can diffuse out of the cell to solubilise bulk S8 0 to form soluble polysulfides (Sx 2-) and/or S8 0 nanoparticles that readily diffuse across dialysis membranes. The Sulfolobales strain lacking SOR required direct contact to oxidise S8 0, which could be overcome by the addition of H2S. High concentrations of S8 0 inhibited the growth of both strains. These results implicate alternative strategies to acquire and metabolise sulfur in Sulfolobales and have implications for their distribution and ecology in their hot spring habitats.

Development and optimization of a self micro-emulsifying drug delivery system (SMEDDS) for co-administration of sorafenib and curcumin.

In this study, we developed a novel co-administration of curcumin and sorafenib using a Self micro-emulsifying Drug Delivery System (SMEDDS) called Sorafenib-Curcumin Self micro-emulsifying Drug Delivery System (SOR-CUR-SMEDDS). The formulation was optimized using star point design-response surface methodology, and in vitro cellular experiments were conducted to evaluate the delivery ratio and anti-tumor efficacy of the curcumin and sorafenib combination. The SOR-CUR-SMEDDS exhibited a small size distribution of 13.48 ± 0.61nm, low polydispersity index (PDI) of 0.228 ± 0.05, and negative zeta potential (ZP) of - 12.4 mV. The half maximal inhibitory concentration (IC50) of the SOR-CUR-SMEDDS was 3-fold lower for curcumin and 5-fold lower for sorafenib against HepG2 cells (human hepatocellular carcinoma cells). Transmission electron microscopy (TEM) and particle size detection confirmed that the SOR-CUR-SMEDDS droplets were uniformly round and within the nano-emulsion particle size range of 10-20nm. The SMEDDS were characterized then studied for drug release in vitro via dialysis membranes. Curcumin was released more completely in the combined delivery system, showing the largest in vitro drug release (79.20%) within 7 days in the medium, while the cumulative release rate of sorafenib in the release medium was low, reaching 58.96% on the 7day. In vitro pharmacokinetic study, it demonstrated a significant increase in oral bioavailability of sorafenib (1239.88-fold) and curcumin (3.64-fold) when administered in the SMEDDS. These findings suggest that the SMEDDS formulation can greatly enhance drug solubility, improve drug absorption and prolong circulation in vivo, leading to increased oral bioavailability of sorafenib and curcumin.

Antibacterial Activity and Cytotoxicity of the Novel Bacteriocin Pkmh.

Bacteriocins are a class of proteins produced by bacteria that are toxic to other bacteria. These bacteriocins play a role in bacterial competition by helping to inhibit potential competitors. In this study, we isolated and purified a novel bacteriocin Pkmh, different from the previously reported bacteriocin PA166, from Pseudomonas sp. strain 166 by ammonium sulfate precipitation, dialysis membrane method, ion exchange chromatography, and gel filtration chromatography. SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) revealed that the molecular weight of Pkmh is approximately 35 kDa. Pkmh exhibited potent antimicrobial activity against bovine Mannheimia haemolytica (M. haemolytica) with low cytotoxicity, and lower hemolytic activity was observed. In addition, Pkmh retained antimicrobial activity at different pH ranges (2-10) and temperature conditions (40, 60, 80, 100 °C). Our analysis of its antimicrobial mechanism showed that Pkmh acts on bacterial cell membranes, increasing their permeability and leading to cell membrane rupture and death. In conclusion, Pkmh exhibited low hemolytic activity, low toxicity, and potent antibacterial effects, suggesting its potential as a promising candidate for clinical therapeutic drugs.

Super high-flux dialyzers improve survival in patients on hemodialysis: a cohort study of the Japanese Society for Dialysis Therapy (JSDT) Renal Data Registry

BackgroundIn Japan dialyzers are classified as type I, II, III, IV, or V on the basis of the β2-microglobulin clearance. In 2023, Type V dialyzers were defined as super high-flux membrane dialyzers. Herein, we investigate the association between dialyzer type and mortality.MethodsA cohort study was conducted using the Japanese Society for Dialysis Therapy Renal Data Registry database from 31 December 2017, to 31 December 2019. We enrolled 181,879 patients on hemodialysis who were divided into type I–V groups per the Japanese classification. We assessed the associations of each group with 2-year all-cause mortality using Cox proportional hazard models. Furthermore, propensity score matching analysis was performed.ResultsBy the end of 2019, 34,196 patients (18.8%) had died. The hazard ratio (95% confidence interval) was significantly higher in the type I (1.25 [1.12–1.39]), type II (1.21 [1.13–1.31]), and type III (1.07 [1.02–1.13]) groups and significantly lower in the type V group (0.86 [0.80–0.92] P < 0.0001) than in the IV group as a reference after adjusting for all confounders. The type V group had a significantly lower adjusted mortality risk regardless of Kt/V and was robust in several sensitivity analyses. Furthermore, the findings remained significant after propensity score matching.ConclusionsThis observational study revealed that hemodialysis performed using super high-flux dialyzers may reduce mortality rates regardless of Kt/V. However, to establish the efficacy of super high-flux dialyzers in improving outcomes, randomized controlled trials should be conducted.Trial registration number: UMIN000018641.

Aqueous colloid flow batteries with nano Prussian blue

Flow battery is a safe and scalable energy storage technology in effectively utilizing clean power and mitigating carbon emissions from fossil fuel consumption. In the present work, we demonstrate an aqueous colloid flow battery (ACFB) with well-dispersed colloids based on nano-sized Prussian blue (PB) cubes, aiming at expanding the chosen area of various nano redox materials and lowering the cost of chemicals. Taking advantage of the two redox pairs of PB, the developed all-PB cell employing a low-cost dialysis membrane with the synthesized PB on both sides displays an open-circuit voltage (OCV) of 0.74 V. Moreover, when paired with an organic tetra pyridine macrocycle the cell with PB as positive electrolyte exhibits an OCV of 1.33 V and a capacity fade rate of 0.039 %/cycle (0.8 %/day). Redox-active colloids exhibit enduring physicochemical stability, with no evident structural or morphological changes after extensive cycling, highlighting their potential for cost-effective and reliable ACFB energy storage.

Hallmarks for Thrombotic and Hemorrhagic Risks in Chronic Kidney Disease Patients.

Chronic kidney disease (CKD) is a global health issue causing a significant health burden. CKD patients develop thrombotic and hemorrhagic complications, and cardiovascular diseases are associated with increased hospitalization and mortality in this population. The hemostatic alterations are multifactorial in these patients; therefore, the results of different studies are varying and controversial. Endothelial and platelet dysfunction, coagulation abnormalities, comorbidities, and hemoincompatibility of the dialysis membranes are major contributors of hypo- and hypercoagulability in CKD patients. Due to the tendency of CKD patients to exhibit a prothrombotic state and bleeding risk, they require personalized clinical assessment to understand the impact of antithrombotic therapy. The evidence of efficacy and safety of antiplatelet and anticoagulant treatments is limited for end-stage renal disease patients due to their exclusion from major randomized clinical trials. Moreover, designing hemocompatible dialyzer membranes could be a suitable approach to reduce platelet activation, coagulopathy, and thrombus formation. This review discusses the molecular mechanisms underlying thrombotic and hemorrhagic risk in patients with CKD, leading to cardiovascular complications in these patients, as well as the evidence and guidance for promising approaches to optimal therapeutic management.

Dialysis nanocomposite membranes based on carbon nanoforms inhibiting blood plasma protein adsorption.

Protein adsorption on medical devices in contact with blood is a significant issue during renal replacement therapy. Main forces determining fouling are the electrostatic interactions between membrane and charged protein, but the dialysis membrane surface charges can be adjusted by modifying the polymer matrix to decrease the blood plasma protein adsorption. In this study, polysulfone membranes (PSU) were modified by incorporation of carbon nanoparticles such as: multiwall carbon nanotubes (2 wt.% MWCNT), graphene oxide (1 wt.% GO), and graphite (5 wt.% GR) during manufacturing process (nonsolvent-induced phase separation, NIPS). The PSU flat sheet membrane was the reference sample. Observed morphology of nanocomposite membranes was similar (SEM imaging); all of them had finger-like pore structure with unimodal distribution of pore size and similar skin-to-support ratio (1:3). The carbon nanoadditives also influenced the surface wettability: hydrophobicity and surface free energy of membranes increased (polar components of energy were reduced, while the dispersive components were increased). The surface charge of nanocomposite membranes increased, when the polymer matrix has been modified with CNT or GR. This significantly affects the adsorption of proteins such as chicken (CSA) and bovine serum albumin (BSA) and reduces blood clotting on the membrane.

In vitro kinetics characterisation of polymeric nanoparticles for anticancer therapy

World Health Organization (WHO) predicts that cancer incidence will increase in the future, thus research involving anticancer agents such as nanoparticles has gained significant importance. Nanoparticles can be made from various materials, but the focus on polymeric chitosan and/or carrageenan-based nanoparticles is significant. Research on these materials investigates dynamic parameters of in vitro drug release, stability under working conditions and stability under storage conditions (in vitro kinetics characterisations). Here, a literature review is conducted to provide in-depth insights on research methodology trends, drawbacks, suitability, suggestions for improvements and findings related to polymeric carrageenan and/or chitosan nanoparticles for anticancer therapy. Journal articles involving nanoparticles made from chitosan and/or carrageenan containing anticancer agents published between 2017 and 2022 were acquired through Google Scholar search using relevant keywords. Generally, the methods used to investigate drug release kinetics of nanoparticles can be categorised into dialysis membrane, sample and separate or direct measurement methods. Studies on the response of physiochemical characteristics towards changes in environment do not vary highly and are generalisable. Stability studies primarily measure the physicochemical changes of nanoparticles as a response measurement towards storage conditions. Both drug release selectivity and physicochemical characteristics response in different pH environments were found to be predictable via the ionisation of polymers and drugs used in different pH. The size of the nanoparticles formed during polyelectrolyte complexation process was found to be at its minimum at a balanced pH, possibly due to increased polymer-polymer attraction. The methods used for in vitro kinetics studies were generalised, and suggestions to address potential sources of errors were given in the current review. The selectivity of drug release and changes in physicochemical characteristics of the nanoparticles in different pH environments were found to largely coincide with the principles of ionisation of nanoparticle constituent.

Human Proenkephalin A 119-159 (penKid) in Extracorporeal Therapies: Ex vivo Sieving Coefficient, Diffusive Clearance, and Hemoadsorption Kinetics

Introduction: Enkephalins, endogenous opioid peptides, are involved in the regulation of renal function. One derived molecule, proenkephalin A, also known as penKid, has been demonstrated to be a reliable biomarker for kidney function and its plasma concentration correlates with measured glomerular filtration rate. penKid is used for prediction and diagnosis of AKI and need of renal replacement therapy (RRT). penKid has also been used to predict the successful weaning from RRT in patients with AKI. Whether the concentration of penKid is affected or not by RRT is a controversial point and there are no studies describing the kinetics of the molecule in such conditions. The low molecular weight (4.5 kDa) would imply free removal by the glomerulus and the dialysis membranes. During RRT, this reduction could not be detected in clinical practice due to the complex kinetics involving either low dialytic clearance or increased production in response to impaired kidney function. The aim of this study was to determine the sieving coefficient and the diffusive clearance of the penKid molecule in conditions of in vitro continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodialysis (CVVHD), respectively, and also the penKid removal ratio in conditions of in vitro hemoadsorption (HA) using a synthetic microporous resin. Methods: Blood spiked with a lyophilized penKid peptide solved in 20 mm dipotassium phosphate and 6 mm disodium EDTA [pH 8] to reach target concentrations is used as testing solution. In each experiment, the blood batch was adjusted at a volume of 1,000 mL, maintained at 37°, and continuously stirred. Samples were collected from blood, ultrafiltrate, and spent dialysate at different times during the experiments. Sieving, clearance, and removal ratio were calculated. Results: Significant removal of penKid was observed in CVVH (sieving 1.04 ± 0.27), in CVVHD (clearance 23.08 ± 0.89), and in HA (removal ratio 76.1 ± 1% after 120 min). Conclusion: penKid is effectively removed by extracorporeal therapies. In presence of anuria, penKid generation kinetics can be calculated based on extracorporeal removal and volume variation. In steady state conditions, declining values may be the result of an initial renal function recovery and may suggest discontinuation and successful liberation from RRT.

Preparation of an anticoagulant polyethersulfone membrane by immobilizing FXa inhibitors with a polydopamine coating

Anticoagulation treatment for patients with high bleeding risk during hemodialysis is challenging. Contact between the dialysis membrane and the blood leads to protein adsorption and activation of the coagulation cascade reaction. Activated coagulation Factor X (FXa) plays a central role in thrombogenesis, but anticoagulant modification of the dialysis membrane is rarely targeted at FXa. In this study, we constructed an anticoagulant membrane using the polydopamine coating method to graft FXa inhibitors (apixaban and rivaroxaban) on the membrane surface. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the membranes. The apixaban- and rivaroxaban-modified membranes showed lower water contact angles, decreased albumin protein adsorption, and suppressed platelet adhesion and activation compared to the unmodified PES membranes. Moreover, the modified membranes prolonged the blood clotting times in both the intrinsic and extrinsic coagulation pathways and inhibited FXa generation and complement activation, which suggested that the modified membrane enhanced biocompatibility and antithrombotic properties through the inhibition of FXa. Targeting FXa to design antithrombotic HD membranes or other blood contact materials might have great application potential.

Numerical and experimental investigation of solute transports through different types of dialyzer membrane

The flow and mass transport through different membrane types from different hemodialyzers are investigated in a co-current direction to emphasize the effect of solute diffusion through the dialyzer membranes. The numerical model consists of the blood flowing in a hollow fiber surrounded by a dialysate flow, where the mass transport and fluid flow were simultaneously calculated. The high flux dialyzers considered in the present study are FINEFLUX FIX-210S eco, ELISIO-210HR, and PEPA FDY-21B, which differ mainly in characteristics of the membrane structure and surface. Urea and maltodextrin solutions are used as model solutes to consider the effect of molecular size difference. The numerically predicted outlet concentrations closely align with experimental values, where the variation between predicted and measured values remain below 10% across all dialyzer types for urea solutions, and specifically below 8% for maltodextrin solution. Among the various dialyzers tested, FINEFLUX membrane could provide the highest maltodextrin clearance (83.09 ml/min) and overall mass transfer area coefficient (KoA) (119.56 ml/min) potentially due to its fast-diffusion characteristic. In this co-current flow study, the results suggest that urea transport is primarily influenced by flow control with minimal impact from boundary layers, while maltodextrin transport is predominantly governed by diffusion control.

A green method for the preparation of carbon quantum dots from yellow lupin peel waste for spectrofluorometric determination of nirmatrelvir

The COVID-19 pandemic has highlighted the urgent need for effective antiviral agents. One such promising drug is nirmatrelvir (NIRMA), which has demonstrated the ability to inhibit viral replication and reduce hospitalization and mortality rates. In the field of analytical chemistry, carbon quantum dots (CQDs) derived from fruit peel waste have gained attention for their eco-friendly and cost-effective properties. In this study, CQDs were synthesized from the peel biomass waste of yellow lupin and utilized for the spectrofluorometric determination of NIRMA in pharmaceutical tablets. The proposed method offers simplicity and speed compared to existing methods. The synthesis process involved washing and grinding the peel waste, followed by heating in propylene glycol and purification using a dialysis membrane. The resulting CQD solution showed fluorescence at an emission wavelength of 411 nm upon excitation at 325 nm. The validation of the method, including linearity, range, limit of detection and quantification, accuracy, precision, and robustness, was conducted following ICH guidelines. The fluorescence intensities exhibited a linear relationship with increasing NIRMA concentration in the range of 15–150 µg/mL. The limit of detection found to be 4.0 μg/mL, with %relative standard deviations ≤ 1.46. This spectrofluorometric method represents a novel approach for the determination of NIRMA using CQDs derived from yellow lupin peel waste.