BSA Adsorption Research Articles

Protein Immobilization on Heterogeneous (SiO2/ZnO) Hollow-Mesoporous Nanocapsules Prepared by Imprinting CPMV: Drug Delivery and Possibility of Immunological Applications.

Herein, we report the protein immobilization and stability studies of heterogeneous hollow mesoporous nanocapsules (Hhmn) for drug and protein delivery. The final results of the diverse precursors such as TEOS, TMOS, APTES, and zinc acetate on the formation of the hollow-mesoporous architecture of nanocapsules have been assimilated in this work. Three types of Hhmn of various sizes were synthesized. Among the three Hhmn, sample I and II nanocapsules were synthesized in the presence of zinc acetate and were identified to be amorphous in nature. Sample III nanocapsules synthesized in the absence of zinc acetate were analogous to the other two synthesized samples. Physiochemical analysis showed the formation of zinc phosphate in the silica matrix for the samples when synthesized with zinc acetate. Specific surface area analysis revealed that sample III has a relatively higher specific surface area. Further, the drug/dye loading and release capacity for the nanocapsules were studied using doxorubicin (DOX) and imatinib mesylate (IM) as model anticancerous drugs and rhodamine 6G as a model dye. Among the synthesized nanocapsules, sample III was shown to have a higher loading capacity for DOX (∼128 μg). From the release kinetic studies of drug/dye, sample III nanocapsules demonstrate a controlled release pattern of DOX and IM. Additionally, protein adsorption and stability studies of samples I and II revealed that the BSA adsorption capacity increases with the increase in the initial concentration of BSA. Furthermore, analysis of the release profiles of BSA and OVA leads to the conclusion that the heterogeneous nanocapsules show a higher loading capacity and sustained release pattern toward OVA. These properties of the nanocapsules highlight their path to immunological applications.

Albumin adsorption on microwave-treated titanium dioxide for dental implant materials

Surface modification of biomedical implants is an established strategy to improve osseointegration. TiO2 nanoflowers (TNF) were deposited on a titanium substrate by hydrothermal technique followed by microwave radiation at 700 W for 5–15 min. Microwave-treated samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy, and Raman spectroscopy to determine their physicochemical characteristics. The XRD and Raman results showed crystalline rutile TiO2. The surfaces of microwave-treated TNF were hydrophilic with split hierarchical structure. The Sips isotherm was used to analyze BSA adsorption on microwave treated TNF samples. The microwave treatment enhances protein adsorption capacity.

Highly Efficient Self-Repairing Slippery Liquid-Infused Surface with Promising Anti-Icing and Anti-Fouling Performance.

Smart slippery liquid-infused porous surfaces (SLIPSs) have aroused remarkable attention owing to tremendous application foreground in biomedical instruments and industry. However, challenges still remain in fabricating durable SLIPSs. In this work, a fast and highly efficient self-repairing slippery surface (SPU-60M) was fabricated based on a polyurethane membrane and silicone oil. By introducing a great quantity of reversible disulfide bonds into the polymer backbone and hydrogen bonds in the polymer interchain, this SLIPS material could be quickly repaired in 15 min with 97.8% healing efficiency. Moreover, the self-healing efficiency could be maintained at 42.75% after the 10th cutting-healing cycle. Notably, SPU-60M showed excellent self-repairing ability not only in an ambient environment but also in an underwater environment and at ultralow temperatures. Besides, the icing delay time (DT) of SPU-60M could be prolonged to 1182 s at -15 °C, and the ice adhesion strength was only 10.33 kPa at -30 °C. In addition, SPU-60M had excellent anti-fouling performance with BSA adsorption of 2.41 μg/cm2 and Escherichia coli CFU counts of 41 × 104. These findings provide a facile way to design highly efficient self-repairing SLIPSs with multifunctionality.

Fabrication of Surface-Imprinted Magnetic Wrinkled Microspheres and Their Specific Adsorption of BSA

Fabrication of Surface-Imprinted Magnetic Wrinkled Microspheres and Their Specific Adsorption of BSA

New insights into the colloidal stability of graphene oxide in aquatic environment: Interplays of photoaging and proteins

Wide application leads to release of graphene oxide (GO) in aquatic environment, where it is subjected to photoaging and changes in physicochemical properties. As important component of natural organic matters, proteins may greatly affect the aggregation behaviors of photoaged GO. The effects of a typical model protein (bovine serum albumin, BSA) on the colloidal stability of photoaged GO were firstly investigated. Photoaging reduced the lateral size and oxygen-containing groups of GO, while the graphene domains and hydrophobicity increased as a function of irradiation time (0–24 h). Consequently, the photoaged GO became less stable than the pristine one in electrolyte solutions. Adsorption of BSA on the surface of the photoaged GO decreased as well, leading to thinner BSA coating on the photoaged GO. In the solutions with low concentrations of electrolytes, the aggregation rate constants (k) of all the photoaged GO firstly increased to the maximum agglomeration rate constants (kfast, regime I), maintained at kfast (regime Ⅱ) and then decreased to zero (regime Ⅲ) as the BSA concentration increased. In both regime I and III, the photoaged GO were less stable at the same BSA concentrations, and the impacts of BSA on the colloidal stability of the photoaged GO were less than the pristine one, which was attributed to the weaker interactions between the photoaged GO and BSA. This study provided new insights into the colloidal stability and fate of GO nanomaterials, which are subjected to extensive light irradiation, in wastewater and protein-rich aquatic environment.

Investigation of BSA adsorption performances of metal ion attached mineral particles embedded cryogel discs

Blood plasma is rich in albumin protein. Albumin has some physiological duties. Investigations over separation of albumin has been paid considerable interest for its excellent potential in blood protein production. Natural pumice particles are non-toxic, reasonably priced and alternative adsorbents with excellent adsorption performance. In order to study the adsorption performance of BSA on composite cryogel discs with immobilized metal affinity chromatography (IMAC), Cu+2-attached natural pumice particles were designed and they were embedded into cryogel generated medium. Cu2+-attached natural pumice particle embedded composite cryogel discs (Cu2+-NP-ECDs) were synthesized through polymerization of gel-former factors at minus temperatures. The characterization experiments of the Cu2+-NP-ECDs were accomplished via SEM, FTIR experiments. The experiments were studied in a batch system. The highest amount of adsorbed BSA (356,8 mg/g particles) onto discs was obtained at pH 7.0 (phosphate buffer), 4 mg/mL concentration of BSA. As a result of conducted 30 adsorption-desorption experiments periods, there was no important change in adsorption performance of composite discs.

Protective effects of non‐catalytic proteins on endoglucanase activity at air and lignin interfaces

The manner in which added non-catalytic proteins during enzymatic hydrolysis of lignocellulosic substrates enhances hydrolysis mechanisms is not completely understood. Prior research has indicated that a reduction in the non-specific adsorption of enzymes on lignin, and deactivation of enzymes exposed to air-liquid interface provide rationale. This work investigated root causes including effects of the air-liquid interface on non-catalytic proteins, and effects of lignin on endoglucanase. Three different experimental designs and three variables (air-liquid interfacial area, the types of lignin (acid or enzymatic lignin), and the presence of non-enzymatic protein (bovine serum albumin [BSA] or soy proteins ) were used. The results showed that acid isolated lignin adsorbed almost all endoglucanase activity initially present in supernatant, independent of air interface conditions (25 or 250 ml flasks) with the presence of BSA preventing this effect. Endoglucanase lost 30%-50% of its activity due to an air-liquid interface in the presence of lignin while addition of non-enzymatic protein helped to preserve this enzyme's activity. Langmuir and Freundlich models applied to experimental data indicated that the adsorption increases with increasing temperature for both endoglucanase and BSA. Adsorption of the enzyme and protein were endothermic with an increase in entropy. These results, combined, show that hydrophobicity plays a strong role in the adsorption of both endoglucanase and BSA on lignin.

Preparation and evaluation of natural rosin-based zinc resins for marine antifouling

Currently, it is highly desirable to develop a novel antifouling resin with a controllable hydrolysis rate and stable and effective antifouling performance for marine antifouling coatings. In our study, we prepared natural rosin-based zinc (RZn-x) resins by a relatively facile and green synthetic method from Zn(OH)2 and antimicrobial natural rosin, which is considered a toxicity-free raw material, thus ensuring the green and antimicrobial character of the material. In their optimal combination, the RZn-x coating surface exhibited ideal peeling behaviour upon immersion in seawater, which caused the WCA of the material surface to change from 55° before immersion to 135° after immersion for 60 days and enhanced the antifouling properties. Dynamic simulation experiments of these resins also demonstrated that the hydrolysis rate of this material immersed in dynamic seawater was related to the zinc content, and we could control the self-polishing ability of the resins by adjusting the content of Zn(OH)2 participating in the reaction. Moreover, hydrolysis led to a hydrophobic surface, which could prevent fouling organisms from adhering. Laboratory bioassays against BSA adsorption (immersed for 4 h: 1.986 μg/cm2), bacterial (over 95 % reduction) and marine algal adhesion (more than 60 % reduction) revealed outstanding anti-protein, bacteriostasis and anti-algal growth and adhesion properties compared to pure rosin and the control sample. The long-term antifouling capability in marine field tests indicated that the RZn-x resins maintained their antifouling activity for more than 6 months, especially RZn-50, which showed excellent antifouling performance.

Modification of Takari natural sand based silica with BSA (SiO<sub>2</sub>@BSA) for biogenic amines compound adsorbent

<abstract> <p>The modification of Takari natural sand‑based silica with bovine serum albumin/BSA (SiO<sub>2</sub>@BSA) as an adsorbent for biogenic amines compounds has been successfully synthesized. The SiO<sub>2</sub>@BSA was synthesized by using the batch method, then was characterized by using FTIR and SEM. Here, A typical BSA group was identified with the new formed namely C–N and C–H, and N–H. The SEM image shows the surface morphology in granular, non‑uniform, rough, and agglomerated forms. Several parameters such as adsorbent dosages, pH, and contact time, shows this material was optimum for adsorption of BSA at pH 5 with adsorbent dosages is 0.1 g during 80 min of contact time. The mechanism adsorption of BSA in this material was found out by using six kinetics modeling, and thermodynamic studies. Here, the adsorption of BSA was fitted with pseudo‑second‑order kinetics. Furthermore, the thermodynamic studies show that adsorption of BSA is spontaneously and follows chemical adsorption.</p> </abstract>

Facile synthesis of PVDF photocatalytic membrane based on NCQDs/BiOBr/TiO2 heterojunction for effective removal of tetracycline

Porous TiO2 nanorods were synthesized by H2SO4 etching method, combined with the synthesis technology of BiOBr-TiO2 heterojunction and NCQDs to synthesis the ternary NCQDs-BiOBr-TiO2 photocatalyst. The micromorphology and structural composition of different powder catalysts and photocatalytic composite membranes were studied by means of various characterization methods. The UV–vis DRS results indicated that the formation of BiOBr-TiO2 heterojunction and the introduction of NCQDs extended the visible light absorption range of photocatalytic materials. The BSA adsorption performances of different composite membranes were investigated, and the results showed that 0.5-NCQDs-BiOBr-TiO2/PVDF composite membranes had strong antifouling properties. Moreover, it was found that the 0.5-NCQDs-BiOBr-TiO2/PVDF composite membranes exhibited high regeneration stability and easy separation recovery performance. The results showed that the TC degradation rate of 0.5-NCQDs-BiOBr-TiO2/PVDF composite membranes reached 77% within 120 min. Moreover, the pseudo first order kinetic apparent rate constant k value of the 0.5-NCQDs-BiOBr-TiO2/PVDF composite membranes was 0.01342 min−1.

Adsorption of Bovine Serum Albumin onto Tannic Acid-Immobilized Chitosan Resin

A novel tannic acid-immobilized chitosan resin (TICR) was prepared by Mannich reaction for the adsorption of proteins. The physical properties of TICR were characterized and the effects of contact time, pH, and initial concentration of (bovine serum albumin) BSA on its adsorption by TICR were investigated. The Langmuir isotherm model was applied to describe the adsorption isotherm. The equilibrium data are fitted to the Langmuir isotherm model. The maximum monolayer BSA adsorption capacities of TICR were found to be 1.094, 1.487, and 1.694 mg/g at 298, 308, and 318 K, respectively. Furthermore, the data were analyzed on the basis of pseudo-first order, pseudo-second order, and intraparticle diffusion models. The correlation results suggested that the pseudo-second order model fitted the experimental data very well. The thermodynamic study indicated that the adsorption process of BSA onto TICR was endothermic, and the Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) of the adsorption process were calculated according adsorption isotherm data. TICR could be reused for 10 times with only 19 % loss of adsorption capacity for BSA.

Corrosion performance of various deformed surfaces of implant steel for coronary stent applications: Effect of protein concentration

This work was done to systematically elucidate the corrosion behavior of austenitic stainless steel subjected to various degree of cold deformation (10 %, 20 % & 30 %). The experiments were performed in phosphate buffer saline (PBS) solution having different concentrations of bovine serum albumin (0.2, 0.5, 1.0, 2.0, 4.0 g L−1). Potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) analysis were performed to obtain the corrosion parameters. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to determine the surface morphologies and chemical compositions of the surface films. Contact angle analysis was also used to detect the hydrophilic character of sample surfaces. The BSA had a considerable effect of inhibition on the corrosion of SSs in annealed as well as in deformed state due to its adsorption on surface of steel. For annealed samples, at 4.0 g L−1BSA concentration, the corrosion resistance was drastically decreased but interestingly not for sample with more than 10 % deformation and the concentration effect of BSA is also not very significant after 0.5 g L-1 for deformed surfaces. The breakdown potential for 30 % deformed sample is quite higher in presence of BSA even at 4.0 g L−1 while it is lowest for annealed samples in the same condition. The variation in contact angle with deformation is very less after adsorption of BSA. On the basis of the obtained results, mechanism aspect for corrosion of steel in presence of protein is also deliberated.

Photocatalytic nanocomposite membranes for high-efficiency degradation of tetracycline under visible light: An imitated core-shell Au-TiO2-based design

Herein, Au-TiO2 nanocomposite photocatalysts were initially constructed through a three-step-synthesis strategy including the sodium citrate reduction method, sol-gel method and high-temperature hydrothermal method. After that, Au-TiO2/PVDF photocatalytic nanocomposite membranes with visible light response were synthesized by a phase conversion process, thereinto, the Au-TiO2 nanocomposite and PVDF powder were mixed into casting solutions by physical blending. Various characterization methods, such as SEM, TEM, FTIR, XRD, XPS, WCA and UV-vis DRS, etc., were used to systematically characterize the micromorphology, structural composition, wettability and optical properties of different samples. The UV-vis DRS results showed that the as-prepared nano-Au doping structure effectively enhanced the utilization factor of visible light in the process of photocatalytic degradation. The antifouling results of BSA adsorption experiments showed that 0.3-Au-TiO2/PVDF composite membranes possessed good antifouling performance. By analyzing the regeneration stability experiments, it could be found that the 0.3-Au-TiO2/PVDF composite membranes also exhibited excellent regeneration stability and easy separation and recovery features. The photocatalytic degradation of different membranes under visible light was investigated with tetracycline. The results showed that the photocatalytic degradation rate of 0.3-Au-TiO2/PVDF nanocomposite membranes reached 75% within 120 min. Moreover, the first-order kinetic linear fitting showed that the k value of 0.3-Au-TiO2/PVDF composite membranes was 0.01212 min−1, which was 2.7 times and 2.0 times higher than that of 0.1-Au-TiO2/PVDF and 0.5-Au-TiO2/PVDF composite membranes. That is to say, photocatalytic activity of 0.3-Au-TiO2/PVDF composite membranes were obviously improved.

The molecular insights into protein adsorption on hematite surface disclosed by in-situ ATR-FTIR/2D-COS study.

Proteins are of ubiquitous interest in the Life Sciences but are of interest in the Geosciences as well because of the significant role these compounds play in the biogeochemical cycling of trace and nutrient elements. Structural changes resulting from the adsorption of proteins onto mineral surfaces may alter protein biological function and other environmental interactions. Iron oxides are major sinks of a range of environmental elements including organic compounds. In this study, the adsorption of the broadly studied model protein BSA onto the hematite mineral surface was characterized as a function of pH, ionic strength, and BSA concentration using in-situ Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. BSA lost the α-helix and gain β-sheets in the secondary structure during adsorption on hematite. BSA adsorption was maximum at pH 5, a value close to the BSA isoelectric point (~ pH 5), and lower at pH 4 and pH 7. Increasing ionic strength decreased to total BSA adsorption. Two-dimensional correlation spectroscopy analysis of the ATR-FTIR spectra revealed that higher initial BSA concentration and the consequent higher BSA surface loading enhanced BSA adsorption by protein–protein interaction, which less ordered structures changes into more compact forms decrease, hence compacting the structural arrangement and could promoting multilayers/aggregation formation on the mineral surface. The activity of enzymes following adsorption on mineral surfaces requires further study.

Metal organic framework nanoparticles loaded- PVDF/chitosan nanofibrous ultrafiltration membranes for the removal of BSA protein and Cr(VI) ions

The UiO-66 NH2 and ZIF-8 metal organic framework nanoparticles (NMOFs) were incorporated into the polyvinylidene fluoride (PVDF) nanofibrous membrane. Then, the chitosan nanofibers were coated on the PVDF nanofibers to produce the PVDF/chitosan nanofibers. The performance of synthesized PVDF/NMOFs single layer and PVDF/chitosan/NMOFs two layers nanofibrous membranes was investigated for BSA protein molecules and Cr(VI) ions separation via ultrafiltration membrane process. The potential of synthesized nanofibers was also examined for BSA and Cr(VI) adsorption in a batch system. The characteristics of synthesized nanofibrous membranes were determined using SEM, EDX, TGA, BET, porosity and water contact angle measurements. The PVDF/chitosan nanofibrous membrane containing 20 wt% UiO-66-NH2, exhibited the maximum water flux of 470 L.m−2 h−1, 98.1% BSA rejection and 95.6% Cr(VI) rejection. The nanofibers were sucessfully regenrated for five adsorption-desorption cycles. The maximum sorption capacities of BSA and Cr(VI) were found to be 574.5 and 602.3 mgg−1, respectively. The obtained results revelaed the high potential of PVDF/chitosan/UiO66-NH2 nanofibers for membrane separation and adsorption of BSA molecules and Cr(VI) ions.

Optimization of sulfonated polyethyleneimine zwitterionic coating mediated by polydopamine for poly(vinyl chloride) antifouling

AbstractAlthough poly(vinyl chloride) (PVC) has been widely used as blood‐contacting materials in extracorporeal circuits and indwelling medical devices, its hydrophobicity also is a limitation due to the adsorption of plasma proteins and the immediately followed thrombosis cascade and bacterial infections. Herein, we developed a mild and simple strategy for improving the hydrophilicity and antifouling properties of the surface via mussel‐inspired chemistry. Different amounts of 1,3‐Propanesultone (1,3‐PS) were attached onto the polyethyleneimine (PEI), so as to modify it into the zwitterion, called PESX. Two layer‐by‐layer approaches about PESX grafting on PVC substrates were designed. One strategy was by coating PESX after coating polydopamine (PDA) on PVC surface, obtaining PDA‐PESX coatings. The other was by grafting PESX after co‐deposition treatment of PDA and PESX with appropriate feeding ratio on PVC, obtaining PDA/PESX‐PESX coatings. The study results indicated that the PDA/PES0.5‐PES0.5 coatings with optimized PEI molecular weight and sulfonation degree, presented about 2.5–3 times reduction in BSA adsorption (0.77 μg/cm2) compared with PDA/PES0.5 (1.93 μg/cm2) and PDA‐PES0.5 (2.26 μg/cm2), and kept long time antifouling stability. Moreover, the more excellent antifouling performance of PDA/PES0.5‐PES0.5 was also seen on fibrinogen (Fg), γ‐globulin (γ‐GL), and the mixture of these proteins. Meanwhile, PDA/PES0.5‐PES0.5 could prevent the adhesion of blood components and bacteria on the surface as well as maintain excellent hemocompatibility and cytocompatibility. We had hopes that our simple and mild strategy will find practical application in surface engineering of clinical use in blood‐contacting medical devices.

BSA adsorption, anthelmintic activity and swelling behavior of poly (N-cyclohexyl acrylamide-co-AMPS IL)hydrogel

In this study, the ionic liquid based hydrogels were synthesized by free radical polymerization. About 0.1 g of dried hydrogel placed in 20 ml of solution containing 4.0 mg/ml of BSA in BR buffer (various pH level) and allowed to equilibrate the swelling at 30 °C. The maximum protein separation 76.1% was achieved at pH 5.0 in room temperature. The hydrogels with various feed compositions possess good antibacterial as well as antifungal activity. The anthelmintic activity of hydrogels suggested that it can be effective against parasitic infections of humans. The DPPH scavenging assay results showed 89.44% of ionic liquid hydrogel as an antioxidant agent.

Effects of Nanotopography Regulation and Silicon Doping on Angiogenic and Osteogenic Activities of Hydroxyapatite Coating on Titanium Implant.

BackgroundAngiogenic and osteogenic activities are two major problems with biomedical titanium (Ti) and other orthopedic implants used to repair large bone defects.PurposeThe aim of this study is to prepare hydroxyapatite (HA) coatings on the surface of Ti by using electrochemical deposition (ED), and to evaluate the effects of nanotopography and silicon (Si) doping on the angiogenic and osteogenic activities of the coating in vitro.Materials and MethodsHA coating and Si-doped HA (HS) coatings with varying nanotopographies were fabricated using two ED modes, ie, the pulsive current (PC) and cyclic voltammetry (CV) methods. The coatings were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), and atomic force microscopy (AFM), and their in vitro bioactivity and protein adsorption were assessed. Using MC3T3-E1 pre-osteoblasts and HUVECs as cell models, the osteogenic and angiogenic capabilities of the coatings were evaluated through in vitro cellular experiments.ResultsBy controlling Si content in ~0.8 wt.%, the coatings resulting from the PC mode (HA-PC and HS-PC) and CV mode (HA-CV and HS-CV) had nanosheet and nanorod topographies, respectively. At lower crystallinity, higher ionic dissolution, smaller contact angle, higher surface roughness, and more negative zeta potential, the HS and PC samples exhibited quicker apatite deposition and higher BSA adsorption capacity. The in vitro cell study showed that Si doping was more favorable for enhancing the viability of the MC3T3-E1 cells, but nanosheet coating increased the area for cell spreading. Of the four coatings, HS-PC with Si doping and nanosheet topography exhibited the best effect in terms of up-regulating the expressions of the osteogenic genes (ALP, Col-I, OSX, OPN and OCN) in the MC3T3-E1 cells. Moreover, all leach liquors of the surface-coated Ti disks promoted the growth of the HUVECs, and the HS samples played a more significant role in promoting cell migration and tube formation than the HA samples. Of the four leach liquors, only the two HS samples up-regulated NO content and expressions of the angiogenesis-related genes (VEGF, bFGF and eNOS) in the HUVECs, and the HS-PC yielded a better effect.ConclusionThe results show that Si doping while regulating the topography of the coating can help enhance the bone regeneration and vascularization of HA-coated Ti implants.

Synthesis of PVDF/MWCNT nanocomplex microfiltration membrane via atom transfer radical addition (ATRA) with enhanced fouling performance

Polyvinylidene fluoride (PVDF) membranes were combined with multiwall carbon nanotubes (MWCNTs) through atomic transfer radical addition (ATRA) to improve flux and fouling resistance. The novel PVDF membranes were achieved by introducing amine-modified MWCNTs including ethylamine, octylamine, and octadecylamine, to improve dispersion and hydrophilicity. ATRA synthesis was conducted by adding a ligand and a catalyst when preparing the PVDF solution. PVDF-modified MWCNT nanocomplex membranes were prepared by the non-solvent induced phase separation process (NIPS), and MWCNTs were chemically combined with the PVDF. The water flux of the AT-E0.01 membrane (2137 LMH) increased by more than 155.3% in comparison with the PVDF membrane (837 LMH). The high protein rejection greater 98% was retained for the AT-E0.01 membrane, and BSA adsorption showed a lower value than the pristine PVDF membrane. This was attributed to formation of a hydration layer on the membrane through increased binding and capture of water molecules by hydrogen bonds and the hydrophilic Cu[DNDP]3MWCNT-EA complex in PVDF polymer. The flux recovery ratio of AT-E0.01 was 92.7% after three cycles of fouling performance, which indicates excellent fouling resistance. As a result, the AT-E0.01 membrane had excellent water flux and fouling resistance due to its high hydration capacity, hydrophilicity, smooth surface, and negatively surface charge.

Highly efficient nanofibrous sterile membrane with anti-BSA/RNA-fouling surface via plasma-assisted carboxylation process

Constructing a functional porous membrane scaffold for the efficient separation of bacteria from protein and nucleic acid drug stock solution remains a great challenge due to the permeability-selectivity trade-off and fouling propensity of membranes. Here, we adopted the nanofiber suspension coating approach to prepare sterile membrane with nanofiber coverage density of 6 g/m2. The carboxylation surface was further achieved through a facile route including alkaline solution activation and low temperature plasma treatment in sequence. As indicated by experimental and theoretical model analysis, nanofibrous membrane treated by alkali and plasma (NFM-APT) possess an ultrathin nanofiber active layer (about 4.7 μm), narrow pore size distribution (average size: 0.1 μm) and high hydrophilicity, which is beneficial for the absolute interception of E. coli, S. aureus and B. diminuta as well as a relative high and stable permeability (7400.4 L/(m2h), 0.2 MPa). Moreover, NFM-APT presents ultralow adsorption of BSA and RNA in the test of continue-flow and static-immersion modes with an excellent reusability after back-washing process, which is superior to the nascent nanofibrous membrane and commercially available PES membrane. The extraordinary anti-BSA/RNA-fouling performance can be attributed to the excellent hydrophilicity of membrane as well as the robust repulsive interaction between the negatively charged carboxyl group grafted on the surface of fiber and the negatively charged BSA&RNA. The NFM-APT also possesses outstanding performance stability, easy operation, and excellent recoverability. This work may provide a new avenue to design and develop next-generation high-performance sterile membrane for bio-separation.