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Journal of Molecular Graphics &... May 2022Protein adsorption at the surface affects the material biocompatibility directly as it is the first reaction that happens when a foreign material comes in contact with...
Protein adsorption at the surface affects the material biocompatibility directly as it is the first reaction that happens when a foreign material comes in contact with blood. In this study, the mechanism of albumin adsorption on hydrophilic and hydrophobic surfaces is investigated. Although it is studied extensively and has been of keen interest for decades, the adsorptive nature of albumin is still not fully understood with contradicting reported studies. This problem results from previous works focusing on mostly qualitative and quantitative adsorption properties of albumin, rather than the specific interaction mechanisms. The variable local surface properties across albumin can significantly impact adsorption and must be explored. In this work, the effect of hydration is found to significantly increase adsorption with minor reductions. The adsorption of albumin on hydrophilic or hydrophobic surfaces is dependent on albumin orientation, which is dictated by local charge effects. Based on these findings, an optimized material surface is proposed to minimize albumin adsorption using functional groups to limit surface availability for hydrophobic interactions while inhibiting excess electrostatic effects at hydrophilic sites. The extent of albumin adsorption and shape change are characterized herein using the heat capacity. Current study identifies interaction mechanisms previously missing in literature, which are responsible for inconsistent adsorption results.
Topics: Adsorption; Albumins; Hydrophobic and Hydrophilic Interactions; Molecular Dynamics Simulation; Surface Properties
PubMed: 34998131
DOI: 10.1016/j.jmgm.2021.108120 -
International Journal of Molecular... Mar 2023The application of the adsorption method in sewage treatment has recently become a hot spot. A novel magnetic clay-biochar composite (BNT-MBC) was fabricated by...
The application of the adsorption method in sewage treatment has recently become a hot spot. A novel magnetic clay-biochar composite (BNT-MBC) was fabricated by co-pyrolysis of bentonite and biomass after being impregnated with Fe (NO)·9HO. Its adsorption capacity for Cd(II) and methyl orange was approximately doubled, reaching a maximum of 26.22 and 63.34 mg/g, and could be easily separated from the solution by using external magnets with its saturation magnetization of 9.71 emu/g. A series of characterizations including surface morphology and pore structure, elemental analysis, functional group analysis and graphitization were carried out, showing that the specific surface area was increased 50 times by loading 20 wt.% bentonite, while its graphitization and oxygen-containing functional groups were also enhanced. The isotherm fitting indicated that Cd(II) was adsorbed in multiple layers, while methyl orange was in both monolayer and multilayer adsorptions. The kinetic fitting indicated that chemisorption was the rate-limiting step of both, and it was also a complex process controlled by two steps with the fitting of intra-particle diffusion. In the binary system of Cd(II) and methyl orange, the co-existing pollutants facilitated the adsorption of the original one, and there was no competition between adsorption sites of Cd(II) and methyl orange. BNT-MBC also exhibited good reusability and can be magnetically recovered for recycling. Thus, the magnetic clay-biochar composite BNT-MBC is a cost-effective and promising adsorbent for simultaneous removing Cd(II) and methyl orange from wastewater.
Topics: Adsorption; Cadmium; Clay; Bentonite; Charcoal; Water; Magnetic Phenomena; Water Pollutants, Chemical; Kinetics
PubMed: 36982828
DOI: 10.3390/ijms24065755 -
Kidney International. Supplement Aug 2000The use of sorbents in different blood purification techniques is reviewed. The sorbents used in these therapies are divided into two groups: (1) Adsorption occurs... (Review)
Review
The use of sorbents in different blood purification techniques is reviewed. The sorbents used in these therapies are divided into two groups: (1) Adsorption occurs fundamentally because of the hydrophobic properties of the sorbents. In this group, the sorbents used in different dialysis techniques are charcoal and nonionic macroporous resins. (2) Adsorption occurs by chemical affinity, such as ion exchange resins and chemisorbents. Sorbents were initially used in hemoperfusion, which caused many adverse events; later, with the use of coated charcoal, these undesired effects decreased or disappeared, but the adsorptive properties, water control, and acid-base balance still created problems. For these reasons, the use of sorbents in the treatment of chronic renal failure was almost totally discontinued. Little by little, interest in these substances has reappeared, and at present, they have been used in combination with other blood purification techniques such as hemodialysis, hemofiltration, peritoneal dialysis, and finally, hemodiafiltration. Within the various hemodiafiltration techniques, paired filtration dialysis-charcoal is being used to regenerate the ultrafiltrate, which is used as the replacement fluid. Charcoal regenerates the ultrafiltrate and transforms it into a physiological solution with a normal electrolyte composition, calcium, bicarbonate, and glucose, having eliminated the majority of both middle and large molecule uremic toxins. If regeneration is done properly, this replacement fluid is bacteria and endotoxin free. Studies currently are underway on the adsorption of different inflammatory substances in the ultrafiltrate, which could lead to improvement in the biocompatibility of the system.
Topics: Adsorption; Charcoal; Hemodiafiltration; Humans; Kidney Failure, Chronic; Urea
PubMed: 10936800
DOI: 10.1046/j.1523-1755.2000.07607.x -
Molecules (Basel, Switzerland) Oct 2020In recent years, molecularly imprinted polymers (MIPs) have become an excellent solution to the selective and sensitive determination of target molecules in complex... (Review)
Review
In recent years, molecularly imprinted polymers (MIPs) have become an excellent solution to the selective and sensitive determination of target molecules in complex matrices where other similar and relative structural compounds could coexist. Although MIPs show the inherent properties of the polymers, including stability, robustness, and easy/cheap synthesis, some of their characteristics can be enhanced, or new functionalities can be obtained when nanoparticles are incorporated in their polymeric structure. The great variety of nanoparticles available significantly increase the possibility of finding the adequate design of nanostructured MIP for each analytical problem. Moreover, different structures (i.e., monolithic solids or MIPs micro/nanoparticles) can be produced depending on the used synthesis approach. This review aims to summarize and describe the most recent and innovative strategies since 2015, based on the combination of MIPs with nanoparticles. The role of the nanoparticles in the polymerization, as well as in the imprinting and adsorption efficiency, is also discussed through the review.
Topics: Adsorption; Molecular Imprinting; Molecularly Imprinted Polymers; Nanoparticles; Polymerization; Polymers
PubMed: 33076552
DOI: 10.3390/molecules25204740 -
Bioresource Technology Jan 2021Citric acid (CA) has been widely used in different industrial sectors, being produced through fermentation of low-cost feedstock. The development of downstream... (Review)
Review
Citric acid (CA) has been widely used in different industrial sectors, being produced through fermentation of low-cost feedstock. The development of downstream processes, easier to operate, environmentally friendly, and more economic than precipitation, is certainly a challenge in CA bioproduction. Large volumes of by-products generated in precipitation require treatment before disposal. Adsorption, extraction, and membrane separation have been shown to have a lower environmental impact than precipitation, but the technological maturity of these methods is still limited. However, reactive extraction and adsorption have great potential for industrial applications. This review shows that there is still much to be explored, both about the factors that are intrinsic to the techniques, but also in their combination for new processes' development. This review reports the most recent advances on CA bioproduction, with significant information about recovery and purification methods involving this highly industrially demanded organic acid.
Topics: Adsorption; Citric Acid; Fermentation
PubMed: 33249260
DOI: 10.1016/j.biortech.2020.124426 -
Langmuir : the ACS Journal of Surfaces... Dec 2020The adsorption of proteins from aqueous medium leads to the formation of protein corona on nanoparticles. The formation of protein corona is governed by a complex...
The adsorption of proteins from aqueous medium leads to the formation of protein corona on nanoparticles. The formation of protein corona is governed by a complex interplay of protein-particle and protein-protein interactions, such as electrostatics, van der Waals, hydrophobic, hydrogen bonding, and solvation. The experimental parameters influencing these interactions, and thus governing the protein corona formation on nanoparticles, are currently poorly understood. This lack of understanding is due to the complexity in the surface charge distribution and anisotropic shape of the protein molecules. Here, we investigate the effect of pH and salinity on the characteristics of corona formed by myoglobin on silica nanoparticles. We experimentally measure and theoretically model the adsorption isotherms of myoglobin binding to silica nanoparticles. By combining adsorption studies with surface electrostatic mapping of myoglobin, we demonstrate that a monolayered hard corona is formed in low salinity dispersions, which transforms into a multilayered hard + soft corona upon the addition of salt. We attribute the observed changes in protein adsorption behavior with increasing pH and salinity to the change in electrostatic interactions and surface charge regulation effects. This study provides insights into the mechanism of protein adsorption and corona formation on nanoparticles, which would guide future studies on optimizing nanoparticle design for maximum functional benefits and minimum toxicity.
Topics: Adsorption; Myoglobin; Nanoparticles; Protein Corona; Silicon Dioxide
PubMed: 33210541
DOI: 10.1021/acs.langmuir.0c01613 -
Scientific Reports Mar 2022Sorghum has been widely used for liquor production and brewing, but how to make efficiently utilize sorghum straw (SS) has become an urgent problem. Meanwhile, the...
Sorghum has been widely used for liquor production and brewing, but how to make efficiently utilize sorghum straw (SS) has become an urgent problem. Meanwhile, the wastewater produced by winemaking is typical organic wastewater with a high ammonium concentration. To solve the problem of resource utilization of SS and remove ammonium from water, SS was used to prepare biochar as an adsorbent for ammonium adsorption. Batch adsorption experiments were carried out to study the influencing factors and adsorption mechanisms of ammonium onto sorghum straw biochar (SSB). The results showed that the adsorption capacity of SSB was much higher than that of SS. The SSB pyrolyzed at 300 °C had the highest adsorption capacity. The favorable pH was 6-10, and the optimal dosage was 2.5 g/L. The adsorption process and behavior conformed to the pseudo-second-order kinetic and Langmuir isotherm adsorption models. The maximum ammonium adsorption capacity of SSB at 45 °C was 7.09 mg/g, which was equivalent to 7.60 times of SS. The ammonium adsorption of SS and SSB was mainly chemical adsorption. The regeneration test indicated that SSB had good regeneration performance after three adsorption-regeneration cycles. This work suggests that SSB could be potentially applied to sewage treatment containing ammonium to achieve the purpose of resource recycling.
Topics: Adsorption; Ammonium Compounds; Charcoal; Sorghum; Water; Water Pollutants, Chemical
PubMed: 35354834
DOI: 10.1038/s41598-022-08591-5 -
Anais Da Academia Brasileira de Ciencias 2023Despite being little explored for petroporphyrins recovery from oils and bituminous shales, adsorption and desorption processes can be feasible alternatives to obtain a...
Despite being little explored for petroporphyrins recovery from oils and bituminous shales, adsorption and desorption processes can be feasible alternatives to obtain a similar synthetic material, and to characterize their original organic materials. Experimental designs were used to analyze the effects of qualitative (e.g., type of adsorbent, solvent, and diluent) and quantitative (e.g., temperature and solid/liquid ratio) variables on the adsorptive and desorptive performance regarding nickel octaethylporphyrin (Ni-OEP) removal using carbon-based adsorbents. The evaluation variables, adsorption capacity (qe ) and desorption percentage (%desorption ) were optimized by means of the Differential Evolution algorithm. The most efficient adsorbent for removing/recovery Ni-OEP was activated-carbon coconut shell, in which dispersive π-π type and acid-base interactions were likely formed. The highest values of qe and %desorption were obtained using toluene as solvent, chloroform as diluent, 293 K as temperature, and 0.5 mg.mL-1 as solid/liquid ratio for adsorption, and a higher temperature (323 K) and lower solid/liquid ratio (0.2 mg.mL-1) for desorption. The optimization process resulted in qe of 6.91 mg.g-1 and %desorption of 35.2%. In the adsorption-desorption cycles, approximately 77% of the adsorbed porphyrins were recovered. The results demonstrated the potential of carbon-based materials as adsorbent materials for obtaining porphyrin compounds from oils and bituminous shales.
Topics: Nickel; Carbon; Adsorption; Porphyrins; Excipients; Solvents
PubMed: 37341271
DOI: 10.1590/0001-3765202320211598 -
PeerJ 2022To realize simultaneous adsorption of heavy metal and antibiotic pollutants by a BC-based recyclable material, FeO magnetic biochar (MBC) was prepared by...
To realize simultaneous adsorption of heavy metal and antibiotic pollutants by a BC-based recyclable material, FeO magnetic biochar (MBC) was prepared by co-precipitation method. Then different ratios of dodecyl dimethyl betaine (BS-12)-modified bentonite (BS-B) were loaded on the surfaces of biochar (BC) and MBC to prepare BS-B-loaded BC and MBC composites, called BS-B/BC and BS-B/MBC, respectively. The physicochemical and structural properties of the composites were characterized by scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric analysis, specific surface area (S) analysis, and vibrating sample magnetometry, and the adsorption efficiencies of BS-B/BC and BS-B/MBC to Cu and tetracycline (TC) were studied. The following results were obtained. (1) Compared with BS-B/BC, BS-B/MBC had decreased pH and cation exchange capacity (CEC) and increased S. The pH, CEC, and S of BS-B/BC and BS-B/MBC decreased with the increase in the BS-12 proportion of BS-B. The surface of BS-B/MBC became rough after FeO loading. (2) The residual rate of BS-B/MBC was higher than that of BS-B/BC after high-temperature combustion, and the residual rate decreased with the increase in the BS-12 proportion of BS-B. The 2D infrared spectra showed that FeO and BS-12 were modified on the surface of BS-B/MBC. MBC and BS-B/MBC had splendid magnetism and could be separated by external magnetic field. (3) Compared with unmagnetized ones, the adsorption effects of Cu and TC on different BS-B/MBCs improved, and the average adsorption rate reached the largest value of 91.92% and 97.76%, respectively. Cu and TC adsorptions were spontaneous, endothermic, and entropy-increasing processes. The pH and S of the material had a great influence on Cu and TC adsorptions, respectively, than CEC.
Topics: Adsorption; Bentonite; Anti-Bacterial Agents; Tetracycline; Magnetic Phenomena
PubMed: 35251788
DOI: 10.7717/peerj.13030 -
International Journal of Environmental... Feb 2023Pharmaceutical residues in water and wastewater have become a worldwide problem with environmental and public health consequences. Antibiotics are of special importance...
Pharmaceutical residues in water and wastewater have become a worldwide problem with environmental and public health consequences. Antibiotics are of special importance because of the emergence of antibiotic-resistant genes. This study evaluates the adsorptive removal of four common fluoroquinolone antibiotics by using natural colemanite as an alternative adsorbent for the first time. Batch adsorption experiments were conducted for the mixture of fluoroquinolones as well as for individual compounds during the isotherm studies. Adsorption kinetic results indicated that the process followed the pseudo-second-order (PSO) model, while the Langmuir model described the sorption isotherms. The effects of pH and temperature on adsorption performance were determined, and the results indicated that the adsorption was endothermic and spontaneous, with increasing randomness at the solid-liquid interface. The effects of real water and wastewater matrices were tested by using tap water, surface water, and wastewater samples. Reusability experiments based on five adsorption-desorption cycles indicated that the adsorption performance was mostly retained after five cycles. The adsorption mechanism was elucidated based the material characterization before and after adsorption. The results indicate that colemanite can be used as an effective and reusable adsorbent for fluoroquinolone antibiotics as well as for other pollutants with similar physicochemical properties.
Topics: Water; Wastewater; Adsorption; Water Purification; Fluoroquinolones; Anti-Bacterial Agents; Water Pollutants, Chemical; Kinetics; Hydrogen-Ion Concentration; Thermodynamics
PubMed: 36768024
DOI: 10.3390/ijerph20032646