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Repeated low-level red-light (RLRL), characterized by increased energy supply and cellular metabolism, thus enhancing metabolic repair processes, has gained persistent worldwide attention in recent years as a new novel scientific approach for therapeutic application in myopia. This therapeutic revolution led by RLRL therapy is due to significant advances in bioenergetics and photobiology, for instance, enormous progresses in photobiomodulation regulated by cytochrome c oxidase, the primary photoreceptor of the light in the red to near infrared regions of the electromagnetic spectrum, as the primary mechanism of action in RLRL therapy. This oxidase is also a key mitochondrial enzyme for cellular bioenergetics, especially for the nerve cells in the retina and brain. In addition, dopamine (DA)-enhanced release of nitric oxide may also be involved in controlling myopia by activation of nitric oxide synthase, enhancing cGMP signaling. Recent evidence has also suggested that RLRL may inhibit myopia progression by inhibiting spherical equivalent refraction (SER) progression and axial elongation without adverse effects. In this review, we provide scientific evidence for RLRL therapy as a unique paradigm to control myopia and support the theory that targeting neuronal energy metabolism may constitute a major target for the neurotherapeutics of myopia, with emphasis on its molecular, cellular, and nervous tissue levels, and the potential benefits of RLRL therapy for myopia.
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Terapia com Luz de Baixa Intensidade , Miopia , Humanos , Miopia/tratamento farmacológico , Retina/metabolismo , Refração Ocular , Dopamina/metabolismoRESUMO
Lincomycin is a widely used aminoglycoside antibiotic. For its separation from fermentation broth in production, solvent extraction is usually applied because of its low cost and high capacity compared to other bioseparation methods. The multistage mixer-settler is a common extraction equipment in commercial production, but it occupies a large area and causes pollution. In this study, a fully enclosed turbine tower was designed and applied in order to replace the mixer-settler. Its structure parameters (turbine diameter, tray porosity) were optimized on the basis of the extraction effect of lincomycin. The results showed that with 35% tray porosity and 28/26 mm turbine diameter of the tower, the extraction rate was kept above 99.0% steadily under 375 rpm/min rotating speed and 60 °C temperature. The extraction effect is much better than mixer-settler and such turbine tower is expected to be applied in the commercial production of lincomycin.
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Antibacterianos , Lincomicina , Aminoglicosídeos , Fermentação , TemperaturaRESUMO
Recyclable aqueous two-phase systems with thermo-responsive phase-forming materials have been employed to separate macromolecules; however, these systems have achieved very limited separation efficiency for small molecules, such as antibiotics. In this study, aqueous two-phase systems composed of the ethylene oxide/propylene oxide copolymer and water were developed to extract alkaline antibiotics from the fermentation broth. In the aqueous two-phase systems with an ethylene oxide ratio of 20 and propylene oxide ratio of 80, the partition coefficients of tylosin and spiramycin reached 16.87 and 20.39, respectively, while the extraction recoveries were 70.67 and 86.70%, respectively. Coupled with mechanism analysis, we demonstrated the feasibility of extracting alkaline antibiotics using this aqueous two-phase system, especially for 16-membered macrolide antibiotics. The molecular dynamic simulation was employed to visualize the process of dual-phase formation and the partition behavior of antibiotics in an aqueous two-phase system. The dynamic simulation revealed the binding energy between the antibiotic and ethylene oxide/propylene oxide copolymers, which provides a simple indicator for screening suitable antibiotics in aqueous two-phase systems. Our recyclable aqueous two-phase systems provide a robust approach for the extraction of 16-membered macrolide antibiotics with ease of operation and high recovery rates, which is appropriate for large-scale extraction in the fermentation industry.
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Óxido de Etileno , Espiramicina , Compostos de Epóxi , Óxido de Etileno/química , Fermentação , Polímeros/química , Temperatura , Tilosina , Água/químicaRESUMO
Aqueous two-phase systems have potential industrial application in bioseparation and biocatalysis engineering; however, their practical application is limited primarily because the copolymers involved in the formation of aqueous two-phase systems cannot be recovered. In this study, two novel alkaline pH-responsive copolymers were synthesized and examined for the extraction of lincomycin. The two copolymers could form a novel alkaline aqueous two-phase systems when their concentrations were both 6% w/w and the pH was 8.4(±0.1)-8.7(±0.1). One copolymer was synthesized using acrylic acid, 2-(dimethylamino)ethyl methacrylate, and butyl methacrylate as monomers. Moreover, 98.8% of the copolymer could be recovered by adjusting the solution pH to its isoelectric point (pH 6.29). The other copolymer was synthesized using the monomers methacrylic acid, 2-(dimethylamino)ethyl methacrylate, and methyl methacrylate. In this case, 96.7% of the copolymer could be recovered by adjusting the solution pH to 7.19. The optimal partition coefficient of lincomycin was 0.17 at 30°C in the presence of 10 mM KBr and 5.5 at 40°C in the presence of 80 mM Ti(SO4)2 using the novel alkaline aqueous two-phase systems.
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Álcalis/química , Lincomicina/isolamento & purificação , Polímeros/química , Concentração de Íons de Hidrogênio , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , ÁguaRESUMO
Molecular imprinting is a promising approach for developing polymeric materials as artificial receptors. However, only a few types of molecularly imprinted polymers (MIPs) are commercially available, and most research on MIPS is still in the experimental phase. The significant limitation has been a challenge for screening imprinting systems, particularly for weak functional target molecules. Herein, a combined method of quantum mechanics (QM) computations and molecular dynamics (MD) simulations was employed to screen an appropriate 2,4-dichlorophenoxyacetic acid (2,4-D) imprinting system. QM calculations were performed using the Gaussian 09 software. MD simulations were conducted using the Gromacs2018.8 software suite. The QM computation results were consistent with those of the MD simulations. In the MD simulations, a realistic model of the 'actual' pre-polymerisation mixture was obtained by introducing numerous components in the simulations to thoroughly investigate all non-covalent interactions during imprinting. This study systematically examined MIP systems using computer simulations and established a theoretical prediction model for the affinity and selectivity of MIPs. The combined method of QM computations and MD simulations provides a robust foundation for the rational design of MIPs.
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In this study, lincomycin was successfully purified by macroporous adsorption resin column chromatography using the HZ3 resin. The optimal separation parameters were set as follows: the column bed height was 33 cm, sample loading capacity was 48 mg/mL and flow rate of loading was 1 mL/min. A mixture of 0.02 mol/L of Na2HPO4â12H2O (pH = 8.5, adjusted using H3PO4) and acetone (80:20, v/v) was used as the eluent. The elution flow rate was maintained at 3 mL/min. Under these parameters, the purity of lincomycin calculated using the standard curve was 99.00 %, with the yield being 97.84 %. This enrichment and separation method of lincomycin is highly regarded owing to its remarkable efficiency and straightforward operation. Thus, the proposed method for the separation and purification of lincomycin holds considerable promise for pharmaceutical applications.
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Lincomicina , Lincomicina/isolamento & purificação , Lincomicina/química , Adsorção , Porosidade , Cromatografia Líquida de Alta Pressão/métodos , Resinas Sintéticas/químicaRESUMO
Herein, 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a model template in a rational design strategy to produce water-compatible noncovalent imprinted microspheres. The proposed approach involved computational modelling for screening functional monomers and a simple method for preparing monodisperse and highly cross-linked microspheres. The fabricated non-imprinted polymer (NIP) and 2,4-d-imprinted polymer (2,4-d-MIP) were characterised, and their adsorption capabilities in an aqueous environment were evaluated. Results reveal that the pseudo-second-order kinetics model was appropriate for representing the adsorption of 2,4-D on NIP and 2,4-d-MIP, with R2 values of 0.97 and 0.99, respectively. The amount of 2,4-D adsorbed on 2,4-d-MIP (97.75 mg g-1) was considerably higher than those of phenoxyacetic acid (35.77 mg g-1), chlorogenic acid (9.72 mg g-1), spiramycin (1.56 mg g-1) and tylosin (1.67 mg g-1). Furthermore, it exhibited strong resistance to protein adsorption in an aqueous medium. These findings confirmed the feasibility of the proposed approach, providing a reference for the development of water-compatible noncovalent imprinted polymers.
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Ácido 2,4-Diclorofenoxiacético , Microesferas , Impressão Molecular , Água , Adsorção , Água/química , Ácido 2,4-Diclorofenoxiacético/análise , Ácido 2,4-Diclorofenoxiacético/química , Polímeros/química , Cinética , Polímeros Molecularmente Impressos/químicaRESUMO
BACKGROUND: Affinity precipitation has been reported as a potential technology for the purification of proteins at the early stage of downstream processing. The technology could be achieved using reversible soluble-insoluble polymers coupled with an affinity ligand to purify proteins from large volumes of dilute solution material such as fermentation broths or plasma. In this study, a thermo-response polymer was synthesized using N-methylol acrylamide, N-isopropyl acrylamide and butyl acrylate as monomers. The molecular weight of the polymer measured by the viscosity method was 3.06 × 104 Da and the lower critical solution temperature (LCST) was 28.0°C.The recovery of the polymer above the LCST was over 95.0%. Human serum albumin (HSA) is the most abundant protein in the human serum system, and it has important functions in the human body. High purity HSA is required in pharmaceuticals. Safe and efficient purification is a crucial process during HSA production. RESULTS: A thermo-response polymer was synthesized and L-thyroxin immobilized on the polymer as an affinity ligand to enable affinity precipitation of HSA. The LCST of the affinity polymer was 31.0°C and the recovery was 99.6% of its original amount after recycling three times. The optimal adsorption condition was 0.02 M Tris-HCl buffer (pH 7.0) and the HSA adsorption capacity was 14.9 mg/g polymer during affinity precipitation. Circular dichroism spectra and a ForteBio Octet system were used to analyze the interactions between the affinity polymer and HSA during adsorption and desorption. The recovery of total HSA by elution with 1.0 mol/L NaSCN was 93.6%. When the affinity polymer was applied to purification of HSA from human serum, HSA could be purified to single-band purity according to SDS-PAGE. CONCLUSION: A thermo-response polymer was synthesized and L-thyroxin was attached to the polymer. Affinity precipitation was used to purify HSA from human serum.
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Polímeros/química , Albumina Sérica/isolamento & purificação , Tiroxina/química , Acrilamidas/química , Acrilatos/química , Adsorção , Precipitação Química , Humanos , Ligantes , Polímeros/síntese químicaRESUMO
In order to predict how mAbs partition in 20% ethylene oxide/80% propylene oxide (v/v) random copolymer (EO20PO80)/water aqueous two-phase system (ATPS), a molecular dynamic simulation model was developed using Gromacs and then validated by experiments. The ATPS was applied with seven kinds of salt, including buffer salt and strong dissociation salt that were commonly employed in the purification of protein. Na2SO4 was shown to have the best effects on lowering EO20PO80 content in the aqueous phase and enhancing recovery. The content of EO20PO80 in the sample solution was decreased to 0.62%±0.25% and the recovery of rituximab increased to 97.88%±0.95% by adding 300 mM Na2SO4 into back extraction ATPS. The viability determined by ELISA was 95.57% at the same time. A strategy for constructing a prediction model for the distribution of mAbs in ATPS was proposed in consideration of this finding. Partition of trastuzumab in ATPS was predicted by the model created using this method and the prediction result was further validated by experiments. The recovery of trastuzumab reached 95.63%±2.86% under the ideal extraction conditions suggested by the prediction model.
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Anticorpos Monoclonais , Simulação de Dinâmica Molecular , Água , Óxido de Etileno , TrastuzumabRESUMO
Ursodeoxycholic acid (UDCA) is not only safer than chenodeoxycholic acid in the treatment of hepatobiliary diseases, but also has a wide range of applications in Acute Kidney Injury and Parkinson's Disease. The purpose of this experiment is to improve the conversion rate of 7-ketocholic acid (7K-LCA) and the yield of ursodeoxycholic acid in aprotic solvents during electrochemical reduction process. Three aprotic solvents were investigated as electrolytes. 1,3-Dimethyl-2-imidazolidinone (DMI) has a stable five-membered ring structure, and 7K-LCA has undergone two nucleophilic reactions and "Walden" inversion, the 7K-LCK was stereoselectively reduced to UDCA. Hexamethylphosphoramide (HMPA) and 1,3-methyl-3,4,5,6-Tetrahydro-2(1H)-pyrimidinone (DMPU) can be attacked by chloride ions to produce by-products. Molecular orbital theory-based simulations were conducted to study the reducibility of three aprotic solvents [hexamethylphosphoramide (HMPA), 1,3-methyl-3,4,5,6-Tetrahydro-2(1H)-pyrimidinone (DMPU), and 1,3-Dimethyl-2-imidazolidinone (DMI)] in combination with experiments. Choose the best solvent based on the simulation results, the electrolysis reaction can be carried out by applying current and voltage when lithium chloride is used as electrolytes. Calculations using Materials Studio showed that Cu, Pb, Hg-Cu, and Ni exhibited the highest binding energies to the substrate in this system. Using Cu as the electrode when the solvent is a 1:1 mix of DMI and HMPA, the conversion rate of 7-ketocholic acid (could reach 98%, the yield of ursodeoxycholic acid was up to 80%. Under the same conditions, linear voltammetry was performed on the electrochemical workstation to study the electrolysis behavior, and the obtained results were consistent with the experiment.
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Photocatalytic hydrogen production as a technology to solve energy and environmental problems exhibits great prospect and the exploration of new photocatalytic materials is crucial. In this research, the ternary composite catalyst of MoS2/Fe2O3/g-C3N4 was successfully prepared by a hydrothermal method, and then a series of characterizations were conducted. The characterization results demonstrated that the composite catalyst had better photocatalytic performance and experiment results had confirmed that the MoS2/Fe2O3/g-C3N4 composite catalyst had a higher hydrogen production rate than the single-component catalyst g-C3N4, which was 7.82 mmol g-1 h-1, about 5 times higher than the catalyst g-C3N4 (1.56 mmol g-1 h-1). The improvement of its photocatalytic activity can be mainly attributed to its enhanced absorption of visible light and the increase of the specific surface area, which provided more reactive sites for the composite catalyst. The successful preparation of composite catalyst provided more channels for carrier migration and reduced the recombination of photogenerated electrons and holes. Meanwhile, the composite catalyst also showed higher stability and repeatability.
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Citric acid is mainly produced in the fermentation industry, which needs complex processes and produces a high amount of CaSO4 as waste. In this study, CO2 has been used to convert calcium citrate to citric acid and CaCO3 by controlling the reaction parameters (reactants ratio, temperature, and pressure). The CaCO3 produced in this conversion could further be used in the fermentation industry for citric acid production. The transformation condition has been optimized by controlling temperature, pressure, reaction time, and mass ratio of calcium citrate and water. The highest conversion could reach up to 94.7% under optimal experimental conditions of 18 MPa of pressure, 65 °C of reaction temperature, 4 h of reaction time, and 2 g/L of calcium citrate/water suspension solution. This method features simple process, easy separation of citric acid, and environmentally friendly process, which could be a potentially alternative route for downstream treatment in fermentation production of citric acid.
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In this research, in order to separate and purify diol-containing macrolide antibiotics, like tylosin, from complex biological samples, molecularly imprinted polymer (MIP) based on boronate affinity for tylosin was synthesized by using precipitation polymerization method with 4-vinylphenylboronic acid (VPBA) and dimethyl aminoethyl methacrylate (DMAEMA) as pH-responsive functional monomers, and N,N'-methylene bisacrylamide (MBAA)/ ethylene glycol dimethacrylate (EGDMA) as the co-crosslinkers that balance the hydrophobicity of the MIP. The synthesized tylosin-MIP had the advantages of high adsorption capacity (120 mg/g), fast pH-responsiveness responsible for the accessibility of imprinted cavities, and high selectivity coefficient towards tylosin versus its analogues (2.8 versus spiramycin, 7.3 versus desmycosin) in an aqueous environment. The mechanism of boronate affinity between tylosin and VPBA in the form of charged hydrogen bonding was analyzed via density functional theory (DFT). MIPs were used to successfully separate diol-containing macrolides through molecularly imprinted solid phase extraction (MISPE). The results show that MIPs prepared in this method have a good application prospect in the separation and purification of the diol-containing macrolide antibiotics.
Assuntos
Antibacterianos/análise , Ácidos Borônicos/química , Interações Hidrofóbicas e Hidrofílicas , Macrolídeos/análise , Impressão Molecular , Polímeros Molecularmente Impressos/síntese química , Acrilamidas/química , Adsorção , Cromatografia Líquida de Alta Pressão , Reagentes de Ligações Cruzadas/química , Teoria da Densidade Funcional , Etilaminas/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Metacrilatos/química , Simulação de Dinâmica Molecular , Extração em Fase Sólida , Temperatura , Tilosina/análise , Tilosina/químicaRESUMO
A novel method of producing ursodeoxycholic acid was developed through electrochemical stereoselective reduction of 7-ketolithocholic acid (7K-LCA) in a undivided electrolytic cell and aprotic solvents as electrolyte. Five aprotic solvents were investigated as electrolytes, the simple structure of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) were easily attacked by chloride ions and undergo nucleophilic reactions, resulting in no target reactions. The structure of hexamethylphosphoric triamide (HMPA) and 1,3-methyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU) is relatively complex, but chloride ions can still attack them, and it was easier for 7K-LCA to directly undergo a reduction reaction under the action of electric current, because of the small steric hindrance of chenodeoxycholic acid (CDCA), 7K-LCA was stereoselectively reduced to CDCA. Due to the stable structure of the five-membered imidazole ring of 1,3-dimethyl-2-imidazolidinone (DMI), 7K-LCA undergoes two nucleophilic and a "Walden inversion", thereby stereoselective reduction of 7K-LCA to UDCA. In DMI, the highest conversion rate of 7K-LCA was 58.3%, the yield of UDCA was 34.9%, ee value was 100%. Linear sweep voltammetry was used to explore the electrochemical behavior of the reaction, and the electrolysis results were consistent with the linear sweep voltammetry. The product was characterized by using IR, 1H NMR and 13C NMR, it confirm the product was UDCA. The method developed in this paper provides a relatively environmentally friendly and low-consumption method for large-scale production of ursodeoxycholic acid, and provides a valuable reference for the asymmetric electrochemical reduction of ketone groups.
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Aqueous two-phase systems (ATPS) have the advantages of environmentally friendly, high mass transfer efficiency, and mild extraction conditions. However, it is difficult to recycle these polymers, which limits the large-scale application of ATPS. In this study, a novel recyclable ATPS was constructed with thermo-responsive polymer PN and pH-responsive polymer PADB4.78 for the partition of tea saponin. PN represents poly-(N-isopropylacrylamide), and PADB4.78 represents poly-(acrylic acid-dimethylamine ethyl methacrylate-butyl methacrylate), where 4.78 in the subscript indicate the isoelectric point of the polymer. The recoveries of PN and PADB4.78 were 95.36% and 93.48%, respectively, after two cycles. Meanwhile, the phase formation mechanism of ATPS was studied by surface tension and low-field nuclear magnetic resonance (LF-NMR). The effects of polymer concentration, pH, temperature, types and concentrations of salt were investigated on tea saponin partition. In the 1.5% (w/v) PN/3.5% (w/v) PADB4.78 ATPS, the optimal partition coefficient (K) of crude tea saponin were 0.15 in the presence of 1.5 mM KCl at pH 7.6 and 25 °C while the extraction recovery (ERb) reached 92.13%. The K and ERb of tea saponin from tea seeds were 0.12 and 94.50% with 7.5 mM LiBr at pH 8.0 and 25 °C, respectively.
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Metacrilatos , Saponinas , Acrilamidas , ÁguaRESUMO
BACKGROUND: The postoperative pain associated with total knee arthroplasty (TKA) is severe for most patients. The analgesic efficacy and safety of preoperative use of selective cyclooxygenase-2 (COX-2) inhibitors for patients undergoing TKA are unclear. OBJECTIVES: We conducted a systematic review and meta-analysis to assess whether the use of selective COX-2 inhibitors before TKA decreases the postoperative pain intensity. METHODS: Data sources: The PubMed, Embase, EBSCO, Web of Science, and Cochrane Controlled Register of Trials databases from inception to January 2020. STUDY ELIGIBILITY CRITERIA: All randomized controlled trials (RCTs) in which the intervention treatment was preoperative selective COX-2 vs placebo in patients undergoing TKA and that had at least one of the quantitative outcomes mentioned in the following section of this paper were included. Letters, review articles, case reports, editorials, animal experimental studies, and retrospective studies were excluded. INTERVENTIONS: All RCTs in which the intervention treatment was preoperative selective COX-2 vs placebo in patients undergoing TKA. STUDY APPRAISAL AND SYNTHESIS METHODS: The quality of the RCTs was quantified using the Newcastle-Ottawa quality assessment scale. RevMan 5.3 software was used for the meta-analysis. RESULTS: Six RCTs that had enrolled a total of 574 patients were included in the meta-analysis. The visual analog scale pain score at rest was significantly different between the experimental group and control group at 24âhours (Pâ<â.05) and 72âhours (Pâ<â.05) postoperatively. The experimental group exhibited a significant visual analog scale pain score during flexion at 24âhours postoperatively (Pâ<â.05), and it was not different at 72âhours postoperatively (Pâ=â.08). There was a significant difference in opioid consumption (Pâ<â.05), but there was no difference in the operation time (Pâ=â.24) or postoperative nausea/vomiting (Pâ=â.64) between the groups. CONCLUSION: The efficacy of preoperative administration of selective COX-2 inhibitors to reduce postoperative pain and opioid consumption after TKA is validated. SYSTEMATIC REVIEW REGISTRATION NUMBER: INPLASY202090101.
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Analgesia/métodos , Artroplastia do Joelho/métodos , Inibidores de Ciclo-Oxigenase 2/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Cuidados Pré-Operatórios/métodos , Idoso , Analgésicos Opioides/uso terapêutico , Inibidores de Ciclo-Oxigenase 2/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Metanálise como AssuntoRESUMO
Neutrophil extracellular traps (NETs) is an antimicrobial cobweb-structured material produced by immune cells for clearance of pathogens in the body, but paradoxically associated with biofilm formation and exacerbated lung infections. To provide a better materials perspective on the pleiotropic roles played by NETs at diverse compositions/concentrations, a NETs-like material (called 'microwebs', abbreviated as µwebs) is synthesized for decoding the antimicrobial activity of NETs against Staphylococcus aureus in infection-relevant conditions. We show that µwebs composed of low-to-intermediate concentrations of DNA-histone complexes successfully trap and inhibit S. aureus growth and biofilm formation. However, with growing concentrations and histone proportions, the resulting microwebs appear gel-like structures accompanied by reduced antimicrobial activity that can even promote formation of S. aureus biofilms. Our simplified model of NETs provides a materials-based evidence on NETs-relevant pathology in the development of biofilms.
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The main problem of poor water compatibility of molecularly imprinted polymers (MIPs) has been addressed in this study. A new facile and highly efficient approach was developed to obtain well-defined hydrophilic molecularly imprinted polymer microsphere with excellent specific recognition ability toward Chenodeoxycholic acid (CDCA) in crude bile. Particularly, it involved computational modeling to obtain a polymer network with high affinity for CDCA and addition of a hydrophilic crosslinker (polyethylene glycol (PEG) diacrylateâ¼200) to increase the hydrophilicity of the polymer surface. To our knowledge, this study first report splitting method in molecular imprinting technology. By using the splitting method, simulation time can be saved under the premise of ensuring accuracy. The adsorption experiments revealed that an optimized CDCA-MIP exhibited better selectivity toward CDCA with inhibition of the nonspecific adsorption. The CDCA-MIP possessed adsorption capacity of 49.86â¯mg g-1 for CDCA and the imprinting factor was 2.72. Solid-phase extraction (SPE) using the prepared CDCA-MIP as adsorbent was optimized regarding loading and elution conditions, and it was used to extract CDCA from crude bile, resulting in recoveries in the range 94.2-96.1%.
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Ácido Quenodesoxicólico/isolamento & purificação , Impressão Molecular/métodos , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Reagentes de Ligações Cruzadas/química , Cinética , Conformação Molecular , Tamanho da Partícula , Polietilenoglicóis/química , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , TermodinâmicaRESUMO
The recyclable aqueous two-phase systems (ATPS) responding to environmental stimuli have been widely studied in the purification of biologics. In this study, a thermo-responsive polymer PNE was copolymerized after optimization of monomer ratio. In addition, its lower critical solution temperature (LCST, 31 °C) and first recovery (99.43%) were determined. Then, PNE was used to form two recyclable ATPS with another thermo-responsive polymer PNDBN and a pH-responsive polymer PADB4.91, which were polymers already prepared in the lab. Meanwhile, the partition behavior of microbial transglutaminase (MTG) was explored using these two ATPS. The result showed that the PNE/PADB4.91 ATPS was superior to PNDBN/PNE ATPS owing to its faster phase formation and better partition performance. In order to optimize the partition behavior, several parameters were investigated based on PNE/PADB4.91 ATPS. In the ATPS constructed with 2.5% (w/v) PNE and 3.5% (w/v) PADB4.91, the maximal partition coefficient (1/KE) and enzymatic recovery (ERB) of MTG were 12.9 and 95.21% in the presence of 10 mM KCl when the temperature, pH, and the addition amount of MTG were 25 °C, 7.0, and 2 mg/mL, respectively.
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Reatores Biológicos/microbiologia , Temperatura , Transglutaminases/metabolismo , Água/química , Concentração de Íons de Hidrogênio , Polímeros/químicaRESUMO
The aim of this study was to elucidate the possible association between migration inhibitory factor (MIF)-173G/C gene polymorphisms and transcript and plasma levels of MIF in spinal tuberculosis (TB) patients. Clinical data were collected from 254 spinal TB patients and 262 healthy controls participating in the study. The genotype of the MIF-173G/C gene was amplified by polymerase chain reaction and genotyped by DNA sequencing technology. The level of mRNA expression was determined by real-time polymerase chain reaction and MIF plasma levels were measured by a solid-phase enzyme-linked immunosorbent assay. The frequency of the C allele and GC+CC genotype in MIF-173G/C was over-represented in spinal TB patients. The mean MIF mRNA level in spinal TB patients and patients with the GG and GC+CC genotype were significantly lower than controls; however, our study also indicated that the MIF concentration in spinal TB patients and patients with the GG and GC+CC genotypes were significantly higher than controls. Spinal TB patients with the GG genotype had higher MIF plasma levels than patients with the GC+CC genotype. The C-reactive protein level and erythrocyte sedimentation rate was correlated with the MIF plasma level. In summary, the association between the MIF-173G/C genetic polymorphism, reduced transcript and increased plasma levels of MIF in spinal TB patients, and MIF may play an important role in the occurrence, development, and damage of spinal TB in the northern Province population of China.