Polymethylmethacrylate Membrane Research Articles

No Improvement of Hepatitis B Vaccination Response in Patients Dialysed with a Polymethylmethacrylate Membrane Compared to High-Flux Polysulfone: Results of the HEPADIAL Study

Background: An altered immune response and decreased vaccine response are observed in patients with chronic renal failure. A preliminary study of 15 non-immunised patients, despite appropriate previous hepatitis B vaccination, showed a 60% seroconversion rate after 3 months of dialysis with a polymethylmethacrylate (PMMA) membrane. This response was associated with circulating soluble CD40 (CD40s) decrease, a natural inhibitor of the humoral immune response. The aim of the study is to confirm these results in a randomised study. Methods: We conducted a multicentre randomised intention-to-treat superiority clinical trial comparing polysulfone and a PMMA membrane in 2 parallel patient groups. The primary end point was the vaccine response rate, as defined by an anti-HBs antibodies titre of >10 IU/L, 1 month after the last vaccination with a double dose of Engerix B20®, performed at weeks 12, 16, 20, and 36. Results: Twenty-five patients were randomised and included in an intention-to-treat analysis. They were dialysed on polysulfone (n = 11) or PMMA (n = 14) for 40 weeks. Fifty percent of the PMMA patients versus 54.5% of the polysulfone patients achieved seroconversion (p = 1.00). The median anti-HBs antibody titre in responders at week 40 was 496 (92–750) versus 395 (43–572) UI/mL for PMMA and polysulfone, respectively (p = 0.46). The median CD40s titre at week 12 was 306 (193–448) versus 491 (281–515) pg/mL (p = 0.21). The CD40s median variation between week 0 and week 12 was 5 (–105 to 90) versus 64 (–63 to 123) pg/mL (p = 0.55). The CD40s level at week 12 in non-responders was slightly inferior to that of the responders: median 193 (168–331) versus 413 (281–512) pg/mL (p = 0.08). Conclusion: We did not observe a better vaccine response with the PMMA membrane compared to high-flux polysulfone. The PMMA membrane did not decrease the CD40s more than the polysulfone membrane probably because the titre was previously low in the 2 groups.

Experience of using polymethyl methacrylate membranes for anti-HLA antibodies’ elimination by hemodialysis in renal transplant recipients

Introduction. In recipients with pre-existing sensitization with incompatible antigens of the main histocompatibility complex, the kidney graft survival after retransplantations directly depends on the level of anti-HLA antibodies. Despite many years of experience in using various methods: plasmapheresis, cascade filtration, immunosorption, intravenous administration of immunoglobulins, the use of polyclonal anti-lymphocytic agents, the search for more acceptable ways to reduce the level of anti-HLA antibodies still remains relevant nowadays.The purpose of the study was to assess the effect of polymethyl methacrylate membrane-based dialyzers on the decrease in anti-HLA antibody level in renal transplant recipients.Material and methods. The study included 20 kidney transplant recipients. The main study group consisted of 10 patients who underwent early postoperatoive hemodialysis using polymethyl methacrylate membrane-based dialyzers to decrease anti-HLA antibody level. A total of 53 hemodialysis procedures were performed, an average of 5.3 per patient. The comparison group included 10 recipients in whom plasmapheresis had been performed at similar timing after kidney transplantation aimed at reducing the anti-HLA antibody titers and whose data were studied retrospectively. A total of 38 plasmapheresis sessions were performed, an average of 3.8 per patient.Results. In the main study group, a day after the hemodialysis procedure using polymethyl methacrylate membranebased dialyzers the level of anti-HLA antibodies decreased by an average of 28.3% in 6 of 10 patients (60%), and increased in 4 cases. Meanwhile, in the comparison group, the level of anti-HLA antibodies in venous blood after a plasmapheresis session decreased average by 44.6% in 8 patients of 10 (80%), and increased in 2 cases, on the contrary. Of note, there were no significant differences between the patients of the two compared groups either in the number of positive results (p> 0.05, Fisher's exact test), or in terms of the decrease in anti-HLA antibody level (p> 0.05, Mann – Whitney test). On days 2 and 5, in 50% of cases both after the hemodialysis procedure using polymethyl methacrylate membranebased dialyzers and after the plasmapheresis session, the patients showed an increase in the anti-HLA antibodies level compared to the baseline values. In the remaining cases, the level of anti-HLA antibodies in both groups was recorded at a lower range compared to the baseline values.Conclusion. The use of polymethyl methacrylate membrane-based dialyzers in the renal allograft recipients having a high level of preexisting anti-HLA antibodies seems promising for the period of oligoanuria until the renal allograft function is restored, since both hemodialysis and the sorption of pre-existing (and also newly synthesized) antibodies take place simultaneously.

Evaluation of Proteins and Cells that Adsorb to Dialysis Membranes Used in Continuous Hemodiafiltration: Comparison of AN69ST, Polymethylmethacrylate, and Polysulfone Membranes

Objective: In intensive care medicine, continuous renal replacement therapy (CRRT) is important for critically ill patients. Various types of dialysis membranes are currently used in clinical settings, each having unique structures and characteristics. This study aimed to perform a detailed analysis of the characteristics of polysulfone (PS), polymethylmethacrylate (PMMA), and polyacrylonitrile (AN69ST) membranes, and to determine differences in the adsorption of proteins and blood cells by membrane material. Methods: Subjects were patients undergoing CRRT in the ICU of the Kokura Memorial Hospital. After use, membranes were collected and analyzed. Semi-quantitative analysis of the membrane surface was performed by scanning electron microscopy. We determined the identity of proteins adsorbed to the surface of membranes by TOF/MS analysis, and measured the amount of adsorbed chemical mediators. Results: Electron microscopy revealed that, compared to PS and PMMA membranes, AN69ST membranes had a greater amount of adsorbed activated white blood cells (WBCs). A large amount of platelets was adsorbed to PMMA membranes. In terms of the amount of adsorbed protein, significantly more proteins adsorbed to AN69ST membranes compared to PS and PMMA membranes. Moreover, TOF/MS analysis revealed a difference in the types of adsorbed proteins by membrane. Chemokines were particularly prevalent among adsorbed proteins for all 3 membranes. Conclusion: Compared to PS and PMMA membranes, AN69ST membranes had a higher capacity to remove activated WBCs. Moreover, apparent differences were noted in the types of proteins that adsorbed to each type of membrane. These differences in membrane properties may impact clinical outcomes.

Comparison of Blood Compatibility in Various Membrane Materials for Continuous Renal Replacement Therapy

Because hemofilters used for continuous renal replacement therapy contact with blood over a prolonged period during treatments, platelet activation may occur stronger. The purpose of this study is to clarify the blood compatibility in three hemofilters mostly used in Japan. We compared the blood compatibility of the two polysulfone (AEF: Asahi Kasei Medical Co., Tokyo, Japan and SHG: Toray Medical Co., Ltd., Tokyo, Japan) and one polymethylmethacrylate membranes (CH: Toray Medical Co., Ltd.). First, test blood was collected from healthy volunteers. Subsequently, the blood was circulated by a roller pump at the rate of 100 mL/min. We measured the platelet counts and platelet factor 4 (PF4). The platelet counts at 48 h in polymethylmethacrylate membrane were significantly less than that in polysulfone membranes. Levels of the PF4 after the circulation were 978.5 ± 200.0 ng/dL with AEF, 863.0 ± 233.9 ng/dL with SHG and 1780.0 ± 465.1 ng/dL with CH, respectively. Hemofilters with polysulfone membranes showed less platelet activation. It was inferred that the amount of PVP, the smoothness of the membrane surface, and the inner diameter of the hollow fiber affect the blood compatibility in the hemofilter.

SP395Improved Immune Responses Due to Using a Polymethylmethacrylate Membrane Dialyzer

SP395Improved Immune Responses Due to Using a Polymethylmethacrylate Membrane Dialyzer

Blending-based poly(vinylidene fluoride)/polymethyl methacrylate membrane for rechargeable lithium-ion batteries

A gel polymer electrolyte based on the blending membranes of poly(vinylidene fluoride) (PVDF)/polymethyl methacrylate (PMMA) has been manufactured through the non-solvent-induced phase separation (NIPS) method. Its physical and electrochemical properties are characterized, and the blending compatibility of the PVDF/PMMA polymer is demonstrated by thermodynamic analysis. The increase in PMMA content has a great effect on surface morphologies of the PVDF/PMMA blending membranes, especially in terms of PM-3 (membrane with the weight ratio of PVDF/PMMA = 6:4). The PM-3 membrane presents satisfactory ionic conductivity (2.18 mS cm−1 at 26 °C), acceptable thermal stability, and superior compatibility with lithium. In addition, its cycle performance (130.7 mAh g−1 after circulating 200 cycles at 1 C) and rate capability (133.3 mAh g−1 at 4 C) are superior to those of the Celgard 2320 (PP/PE/PP) separator. It is indicated that the PVDF/PMMA blending membrane is promising for the fabrication of rechargeable lithium-ion battery.

Gas-assisted thermal bonding of thermoplastics for the fabrication of microfluidic devices

The challenges for high-strength adhesive-free sealing of thermoplastic microfluidics have impeded commercialization. We present the technique of gas-assisted thermal bonding (GATB) for joining thermoplastic surfaces at elevated temperatures to produce microfluidic devices with low distortion. In this technique a pressurized gas is used to supply the force to bond the two substrates rather than relying on direct contact of thermoplastics with a rigid press. Mechanical characterization tests were performed to analyze and optimize the effect of GATB pressure and temperature on the bonding strength of laminated polymethyl-methacrylate (PMMA) membranes. Tensile tests on PMMA membranes subjected to GATB process conditions examined the effects of these conditions on the single membrane’s characteristics. Adhesive strength was assessed on thin PMMA strips bonded together by GATB in lap shear and T-peel test configurations. The maximum lap shear and peel strength were found to occur at the lowest tested pressure of 1.17 MPa based on bonding experiments at 160 °C and 180 °C, respectively. Thereafter, the GATB is compared with the conventional plate-to-plate method to bond a capping sheet on pre-fabricated microchannels. Channel deformation is quantified by cross-section imaging before and after the sealing experiments. It was found that GATB enables low-distortion microchannels with higher uniformity at elevated temperatures, providing a solution for adhesive-free manufacturing of thermoplastic-based microfluidic systems.

Rheological Issues of Phase Change Materials Obtained by the Complex Coacervation of Butyl Stearate in Poly Methyl Methacrylate Membranes

The research started from the fact that the coacervation process represents the process of formation of macromolecular aggregates after separation from the phase that takes place in a homogeneous polymer solution as a result of the addition of a non-solvent. This process is very complex, and takes place in several stages of emulsification technology. The first step of the research created a sample through an encapsulation process of complex coacervation, followed by the creation of three different samples with specific emulsification technologies. Each resulting sample and step of emulsification went through rheological analysis, including the development of evolutions of the complex viscosity, loss module and respective storage module. When we analyzed the rheological properties of each sample at different emulsification stages, we reached the conclusion that, at the moment when the polymerization reaction develops the methyl methacrylate (MMA), the loss modules of the samples were stronger than the storage modules. In this context, the emulsification technology strongly influenced the process of forming the polymethyl methacrylate (PMMA) layer over the butyl stearate particles. In addition, in order to obtain the corresponding microcapsules, it was preferable for the butyl stearate particles covered with MMA to be vigorously stirred in a short period of time, under 250 s, because after that the polymerization process of the MMA on the surface of the particles begins. When producing microcapsules, it is very important that the whole process of emulsification be accompanied by rigorous stirring.

The clinical evaluation of novel polymethyl methacrylate membrane with a modified membrane surface: a multicenter pilot study

BackgroundPolymethyl methacrylate (PMMA) membranes have the unique property of adsorption, which can remove medium- and large-weight molecular substances that cannot be removed by normal hemodialysis and hemodiafiltration. Filtryzer® NF (NF) is a newly developed PMMA membrane that suppresses platelet adhesion on the membrane surface and retains an adsorption property. NF is expected to improve inflammatory conditions and clinical symptoms in hemodialysis patients compared with conventional PMMA membranes.MethodsThirty-seven maintenance hemodialysis patients treated with polysulfone (PS) membranes and who had detectable chronic inflammation were enrolled into the study. The patients were randomly allocated into the NF and PS groups and observed for 1 year. C-reactive protein (CRP) values were measured as the primary endpoint. Nutrition, blood cell count, and dialysis itchiness were evaluated as secondary endpoints.ResultsSignificant differences in CRP values were not found between the NF and PS groups. In the PS group, the creatinine generation rate (%CGR) and platelet count, which were included in nutrition and blood cell count, respectively, significantly decreased after 6 and 9 months compared with the start of study, but these parameters did not significantly change in the NF group within 1 year. Dialysis itchiness in the NF group was significantly improved compared with the PS group after 9 months.ConclusionsOur results showed that a new PMMA membrane, NF, has a potential to maintain nutritional conditions and the platelet counts and improve dialysis itchiness.Trial registrationThis study is retrospectively registered with the Clinical Trials Registry of the University Hospital Medical Information Network on February 17, 2015 (registration ID, UMIN000016567).

Fabrication of comb-drive actuators for straining nanostructured suspended graphene

We report on the fabrication and characterization of an optimized comb-drive actuator design for strain-dependent transport measurements on suspended graphene. We fabricate devices from highly p-doped silicon using deep reactive ion etching with a chromium mask. Crucially, we implement a gold layer to reduce the device resistance from ≈51.6 kΩ to ≈236 Ω at room temperature in order to allow for strain-dependent transport measurements. The graphene is integrated by mechanically transferring it directly onto the actuator using a polymethylmethacrylate membrane. Importantly, the integrated graphene can be nanostructured afterwards to optimize device functionality. The minimum feature size of the structured suspended graphene is 30 nm, which allows for interesting device concepts such as mechanically-tunable nanoconstrictions. Finally, we characterize the fabricated devices by measuring the Raman spectrum as well as the a mechanical resonance frequency of an integrated graphene sheet for different strain values

Extracorporeal Detoxification in Abdominal Sepsis in Cancer Patients

The purpose is to evaluate the detoxification effects of the polymyxin sorption columns and filtration detoxification using polymethyl methacrylate membranes in abdominal sepsis in cancer patients. Materials and Methods . We examined 226 patients with oncological diseases of abdominal organs complicated by abdominal sepsis postsurgery. In 50 cases, septic shock was reported. In 173 patients an acute renal injury (ARI) was diagnosed in the structure of organ failures, of which a combination with acute respiratory distress syndrome (ARDS) was diagnosed in 61 patients. The severity was 26.3±3.3 points (APACHE-II scale), 10.2±2.5 points (SOFA scale), and 4.3±1.8 points (qSOFA scale). Microbiological identification was obtained in 155 (68.6%) cases. The polymyxin column sorption was used in 86 patients 2–6 hours after sepsis was diagnosed with the EAA greater than 0.5. The blood flow rate was 80–150 mL/min; the duration was 120–240 min; the sorption frequency was 2–3 sessions at a 24-hour interval. If ARI and ARDS were developed, detoxification by filtration using a dialyzer with a BK-1.6F polymethylmethacrylate membrane was included in the complex treatment of 144 patients. The detoxification was carried out for 8–12 hours changing the dialyzer every 4 hours. Results . A statistically significant decreases of hyperthermia, leukocytosis, neutrophilia, procalcitonin, and the EAA test values were revealed after the completion of the sorption treatment. Normalization of hemodynamic parameters, increase of the oxygenation index, and SOFA scoring decrease by 5.6±2.1 points (P<0.05) were found. PCT and IL-6 blood levels decreased from 6.7±2.7 ng/mL to 2.3±0.6 ng/mL and from 7300±7700 pg/mL to 860±180 pg/mL, respectively, as determined 60 minutes after completion of filtration detoxification procedure (P<0.05). The SOFA index decreased by 4.1±1.1 points (P<0.05). Conclusion . The use of polymyxin column sorption and filtration detoxification using a polymethyl metacrylate membrane improves the results of treatment of abdominal sepsis in cancer patients.

Continuous renal replacement therapy with a polymethyl methacrylate membrane hemofilter suppresses inflammation in patients after open-heart surgery with cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) induces a complex inflammatory response involving an increase in inflammatory cytokines, called postperfusion syndrome. Previous studies demonstrated that adsorption of the serum cytokines can reduce acute inflammation and improve clinical outcomes. In this study, patients were placed on continuous renal replacement therapy (CRRT) with a polymethyl methacrylate (PMMA) membrane hemofilter immediately after the start of an open-heart surgery with CPB and throughout the postoperative course to prevent postperfusion syndrome. The aim of this study was to assess whether continuous CRRT using a PMMA filter (PMMA-CRRT) could affect cytokine expression and improve perioperative outcomes. We designed a randomized controlled trial, which included 19 consecutive adult patients on maintenance dialysis and 7 consecutive adult patients who were not on maintenance dialysis (NHD group). Patients on maintenance dialysis were randomly divided into two groups: Ten patients who received CRRT with a polysulfone membrane hemofilter (PS group) and nine patients who received CRRT with a PMMA membrane (PMMA group). Blood samples were collected from the radial or brachial artery at five different time points. Comparisons between the PS, PMMA, and NHD groups revealed a significant main effect of time on changes in serum IL-6 and IL-8 concentrations (p < 0.01) and an interaction (p < 0.05) between time and group. Plasma IL-6 and IL-8 levels after surgery were significantly lower in the PMMA group than in the PS group, while other cytokines measured in this study were not significantly different. In addition, clinical outcomes were not significantly different between the groups. The continuous use of PMMA-CRRT throughout the perioperative period suppressed serum IL-6 and IL-8 concentrations, although there were no differences in clinical outcomes.

Effectiveness of IHD with Adsorptive PMMA Membrane in Myeloma Cast Nephropathy: A Cohort Study

Background: In patients with cast nephropathy and acute kidney injury (AKI) requiring dialysis, the reduction of serum free light chains (FLC) using chemotherapy and intensive hemodialysis (IHD) with a high cut-off filter may improve renal and patient outcomes. We evaluated the effectiveness of a combination of chemotherapy and IHD with an adsorbent polymethylmethacrylate membrane (IHD-PMMA) on renal recovery and survival. Methods: A single-center retrospective cohort-study was conducted. Between 2007 and 2014, patients with dialysis-dependent acute cast nephropathy treated with chemotherapy and IHD-PMMA were included. Patients had six 6-h hemodialysis sessions a week, until predialysis serum FLC fell below 200 mg/L, for a maximum of 3 weeks. Primary outcomes were renal recovery, defined as dialysis independence, and survival. Results: Seventeen patients were included, all with stage 3 AKI. All received chemotherapy, mostly based on bortezomib and steroids (88%). Twelve patients (71%) achieved renal recovery, usually within 60 days (92%). At 3 months, the overall hematological response rate was 57%; hematological response was maintained for at least 2 years in 86% of responders. At 6, 12, and 24 months, 76, 75, and 62% of patients were alive, respectively. Higher reduction in involved FLC by day 12 (p = 0.022) and day 21 (p = 0.003) was associated with renal recovery. Patients with FLC reduction rate >50% by day 21 experienced a lower mortality (hazard ratio 0.10, 95% CI 0.02–0.63). Conclusion: In patients with dialysis-dependent myeloma cast nephropathy, early FLC removal by IHD-PMMA combined with chemotherapy was associated with high rates of renal recovery and survival.

Efficacy of Continuous Haemodiafiltration Using a Polymethylmethacrylate Membrane Haemofilter (PMMA-CHDF) in the Treatment of Sepsis and ARDS

Efficacy of Continuous Haemodiafiltration Using a Polymethylmethacrylate Membrane Haemofilter (PMMA-CHDF) in the Treatment of Sepsis and ARDS

Effect of dialyzer membrane materials on survival in chronic hemodialysis patients: Results from the annual survey of the Japanese Nationwide Dialysis Registry.

BackgroundLittle information is available regarding which type of dialyzer membrane results in good prognosis in patients on chronic hemodialysis. Therefore, we conducted a cohort study from a nationwide registry of hemodialysis patients in Japan to establish the association between different dialyzer membranes and mortality rates.MethodsWe followed 142,412 patients on maintenance hemodialysis (female, 39.1%; mean age, 64.8 ± 12.3 years; median dialysis duration, 7 [4–12] years) for a year from 2008 to 2009. We included patients treated with seven types of high-flux dialyzer membranes at baseline, including cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause mortality as hazard ratios (HRs) and 95% confidence intervals for 1-year mortality adjusting for potential confounders, and propensity score matching analysis was performed.ResultsThe distribution of patients treated with each membrane was as follows: PS (56.0%), CTA (17.3%), PES (12.0%), PEPA (7.5%), PMMA (4.9%), PAN (1.2%), and EVAL (1.1%). When data were adjusted using basic factors, with PS as a reference group, the mortality rate was significantly higher in all groups except for the PES group. When data were further adjusted for dialysis-related factors, HRs were significantly higher for the CTA, EVAL, and PEPA groups. When the data were further adjusted for nutrition-and inflammation-related factors, HRs were significantly lower for the PMMA and PES groups compared with the PS group. After propensity score matching, HRs were significantly lower for the PMMA group than for the PS group.ConclusionThe results suggest that the use of different membrane types may affect mortality in hemodialysis patients. However, further long-term prospective studies are needed to clarify these findings, including whether the use of the PMMA membrane can improve prognosis.

High-Performance Membrane Dialyzers and Mortality in Hemodialysis Patients: A 2-Year Cohort Study from the Annual Survey of the Japanese Renal Data Registry

Background: Little information is available regarding the type of dialyzer which results in good prognosis. This study is aimed at investigating the association between 7 types of dialyzers and 2-year mortality. Methods: We conducted a cohort study using data from a nationwide registry of the Japanese Society for Dialysis Therapy. Subjects were 136,676 patients on maintenance hemodialysis (HD) between 2009 and 2011 who underwent maintenance HD for at least 2 years and were treated with one of the following 7 types of high-performance membrane dialyzers: cellulose triacetate (CTA), ethylene vinyl alcohol (EVAL), polyacrylonitrile (PAN), polyester polymer alloy (PEPA), polyethersulfone (PES), polymethylmethacrylate (PMMA), and polysulfone (PS). Cox regression was used to estimate the association between baseline dialyzers and all-cause 2-year mortality, adjusting for potential confounders. Results: Data were adjusted using basic factors, with PS as a reference group, and the hazard ratio (HR) was significantly higher in CTA, PMMA, PAN, and EVAL groups. Further data adjustment for Kt/V yielded the same results as were obtained from data adjusted for basic factors. After further adjustment for nutrition- and inflammation-related factors, HR was significantly lowered for the PES and PMMA groups compared with the PS group (HR 0.88; 95% CI 0.82-0.94 and HR 0.84 95% CI 0.76-0.93, respectively). After propensity score matching, HR for the PES and PMMA groups was significantly lowered compared with the PS group. Conclusions: The use of different membrane types may affect mortality. Further long-term prospective studies are needed to clarify whether the PES and PMMA membranes can improve prognosis.

Efficacy of continuous haemodiafiltration using a polymethylmethacrylate membrane haemofilter (PMMA-CHDF) in the treatment of sepsis and acute respiratory distress syndrome (ARDS)

CHDF using with a polymethymethacrylate membrane is currently widely applied for non-renal indications in Japan, this technique is used in the treatment not only of patients with sepsis but also of those with cytokine-induced critical illness such as ARDS and pancreatitis. This study aimed to investigate the clinical efficacy of PMMA-CHDF in the treatment of a patients with sepsis and ARDS.

Fabrication of PMMA Membranes with Nano-Pillars Array Using Template/Spin-Coating Method

Template/spin-coating method was presented for fabricating single-layer nano-pillar array polymethylmethacrylate (SL-PMMA) and double-layer nano-pillar array polymethylmethacrylate (DL-PMMA) membranes. The different mass ratio of PMMA/DiMethyl Formamide (DMF) solution was dripped on single-layer porous anodic alumina (SL-PAA) or double-layer porous anodic alumina (DL-PAA) membrane and spun at 4000rpm speed for 30 seconds. The SL-PAA and DL-PAA membranes had been put into vacuum oven at 150°C for 2 hours, before SL-PMMA and DL-PMMA were removed. Experimental results show that the regularity degree of PAA fabricated in OAS/PAS is higher than that of PAA fabricated in PAS by two-step anodization method. The ordered pores and clear double-layer outline can be observed from the surface and cross-section FESEM images of DL-PAA membranes. When the content of PMMA in mixture solution is 20 wt%, the top shape of nano-pillars is convex, because the solution was completely filled in the pore of SL-PAA, and the length of nano-pillars is equal to the height of pore of PAA. However, the top pore amount on nano-pillars at ascending speed 20°C per minute is more than that of at ascending speed 10°C per minute. The PMMA membranes with ordered mid-hollow and porous nano-pillars will have wide application prospect in biosensors, chemical sensors, microcapsules fabrication fields due to many advantages such as simple operation, low cost, high specific surface area, etc.

HBV Vaccination in the Patient with Chronic Renal Disease

Patients undergoing hemodialysis often present with a reduced response to anti-hepatitis B virus (anti-HBV) vaccination. The soluble form of CD40 (sCD40) is elevated in hemodialysis patients and this has been shown to correlate with lack of response to anti-HBV vaccination. Due to its high molecular weight, conventional dialyzers cannot clear sCD40. Dialysis membranes in polymethylmethacrylate (PMMA) can reduce the levels of sCD40. We have used PMMA membranes in patients who were non-responders to anti-HBV vaccination (anti-HB antibody level<10 UI/L after 2 vaccinations circles). Interestingly, we found that significantly more patients in the PMMA group were able to mount a response to vaccination, compared to the control group.

Continuous Hemodiafiltration with an AN69ST Hemofilter (AN69ST-CHDF) as FGF-23-Lowering Therapy.

Recent studies have shown that fibroblast growth factor-23 (FGF-23) is elevated not only in chronic kidney disease (CKD), but also in acute illnesses such as acute kidney injury, septic shock, and acute heart failure. FGF-23 would be not only a simple biomarker but also a direct toxic factor in acute illness. Therefore, lowering circulating FGF-23 levels in clinical practice would be an exciting and valuable interventional strategy. Continuous hemodiafiltration (CHDF) is often performed for the treatment of the aforementioned acute illnesses. We have previously reported that an acrylonitrile-co-methallyl sulfonate surface-treated (AN69ST) membrane has a greater capacity for in vitro FGF-23 adsorption than polysulfone and polymethyl methacrylate membranes. However, reports related to the influence of AN69ST-CHDF on serum FGF-23 levels in acute illness are lacking. In this study, we investigated the effect of AN69ST-CHDF on circulating FGF-23 concentrations in clinical practice. Subjects comprised six inpatients who underwent AN69ST-CHDF for an acute illness. Blood samples for the measurement of serum FGF-23 were collected at 0, 3, and 12 hours post-treatment. Blood samples were also drawn from the extracorporeal circuit at the inlet and outlet of the hemofilter 3 hours after CHDF initiation, in order to calculate the clearance of serum FGF-23. Three and 12 hours after the start of AN69ST-CHDF, circulating FGF-23 levels decreased from baseline values with a marginal statistical significance (p = 0.0625 and 0.0938, respectively). An FGF-23 clearance of 27.5 [interquartile range: 19.4 - 29.2] mL/minute 3 hours after the initiation of AN69ST-CHDF was achieved. Our results suggest that AN69ST-CHDF can be a novel FGF-23 lowering therapy for acute illnesses requiring acute blood purification.