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1.
Chem Soc Rev ; 53(7): 3273-3301, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38507263

RESUMEN

Oral diseases are prevalent but challenging diseases owing to the highly movable and wet, microbial and inflammatory environment. Polymeric materials are regarded as one of the most promising biomaterials due to their good compatibility, facile preparation, and flexible design to obtain multifunctionality. Therefore, a variety of strategies have been employed to develop materials with improved therapeutic efficacy by overcoming physicobiological barriers in oral diseases. In this review, we summarize the design strategies of polymeric biomaterials for the treatment of oral diseases. First, we present the unique oral environment including highly movable and wet, microbial and inflammatory environment, which hinders the effective treatment of oral diseases. Second, a series of strategies for designing polymeric materials towards such a unique oral environment are highlighted. For example, multifunctional polymeric materials are armed with wet-adhesive, antimicrobial, and anti-inflammatory functions through advanced chemistry and nanotechnology to effectively treat oral diseases. These are achieved by designing wet-adhesive polymers modified with hydroxy, amine, quinone, and aldehyde groups to provide strong wet-adhesion through hydrogen and covalent bonding, and electrostatic and hydrophobic interactions, by developing antimicrobial polymers including cationic polymers, antimicrobial peptides, and antibiotic-conjugated polymers, and by synthesizing anti-inflammatory polymers with phenolic hydroxy and cysteine groups that function as immunomodulators and electron donors to reactive oxygen species to reduce inflammation. Third, various delivery systems with strong wet-adhesion and enhanced mucosa and biofilm penetration capabilities, such as nanoparticles, hydrogels, patches, and microneedles, are constructed for delivery of antibiotics, immunomodulators, and antioxidants to achieve therapeutic efficacy. Finally, we provide insights into challenges and future development of polymeric materials for oral diseases with promise for clinical translation.


Asunto(s)
Antiinfecciosos , Polímeros , Polímeros/química , Materiales Biocompatibles/química , Antiinflamatorios , Factores Inmunológicos
2.
J Microencapsul ; 40(3): 157-170, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36825613

RESUMEN

AIMS: The aim of this study is to develop a liposome that could exert unparalleled antioxidant effects. In the present study, a vitamin C (VC)/vitamin E (VE)-co-loaded multivesicular liposome (VCVE-MVL) was constructed. METHODS: Vitamins were encapsulated in soybean phosphatidylcholine (SPC) and cholesterol (CHO) by multi-emulsification method. The concentration of VC was determined by Fast Blue method. The concentration of VE was determined by high performance liquid chromatography (HPLC). Vitamin antioxidant capacity in vitro and in vivo was determined using ß-carotene bleaching. RESULTS: VCVE-MVL with particle diameter of 848.55 ± 0.29 nm and SPAN of 0.16 ± 0.11 were obtained. The encapsulation efficiency of VC reached 48.51% (w/w)±0.15. Compared with VC/VE solution, VCVE-MVL had a higher permeation efficiency. In addition, the in vitro and ex-vivo antioxidant tests verified the adequate antioxidant activity of VCVE-MVL. CONCLUSIONS: In conclusion, the antioxidant synergistic system we constructed and demonstrated its potential applications in the cosmetics industry.


Asunto(s)
Antioxidantes , Vitamina E , Antioxidantes/farmacología , Antioxidantes/química , Ácido Ascórbico , Liposomas/química , Vitaminas
3.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(5): 557-561, 2023 Sep 30.
Artículo en Zh | MEDLINE | ID: mdl-37753897

RESUMEN

With the highlighted advantages of 3D printing technology in the field of dental prosthodontics, there is increasing in the numbers of registration applications for additive manufacturing customized dentures. However, there is still a lack of unified analysis in the core elements of process control, the key points of registration and the safety production quality control. Based on the current research status of the industry, the study is intended to clarify confusion and difficulties, deeply analyse the mechanism of the product defects, sort the core elements of process control, then try to establish a systematic evaluation system from product performance research, key process verification, production quality control and the description of registration files, so that it can provide help for practitioners to clarify research direction, establishing quality management system, improving the efficiency of registration and ensuring product quality.

4.
Soft Matter ; 18(36): 6888-6898, 2022 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-36043893

RESUMEN

We propose a possible strategy that may experimentally generate long polymeric chains with an entanglement-free structure. The basic idea is designing the conditions to restrict polymer chains from growing along the surface with an obviously concave curvature. This strategy is proved to effectively reduce the chance of forming both inter- and intra-molecular entanglements, which is quite similar to the self-avoiding random walking of chains on a two dimensional plane. We believe that this kind of chain growth strategy may supply a kind of possible explanation on the formation of the entanglement-free structure of chromosomes, which also have tremendously large molecular weight. Besides, this study also guides experimentalists on synthesizing specific entanglement-free functional polymeric or biological materials.


Asunto(s)
Polímeros , Peso Molecular , Polímeros/química
5.
J Hepatol ; 65(4): 700-710, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27245431

RESUMEN

BACKGROUND & AIMS: Hepatitis B virus (HBV) RNA in serum has recently been linked to efficacy and prognosis of chronic hepatitis B (CHB) treatment. This study explored the nature, origin, underlying mechanisms, and potential clinical significance of serum HBV RNA. METHODS: The levels of HBV DNA and RNA were determined in the supernatant of induced HepAD38, HBV-expressing HepG2.2.15 cells and primary human hepatocytes (PHH), and in the serum of transgenic mice and CHB patients. NP-40 and proteinase K treatment, sucrose density gradient centrifugation, electron microscopy, northern blot, multiple identification PCRs and 5' rapid-amplification of cDNA ends were performed to identify the nature of serum HBV RNA. RESULTS: Although significantly lower than HBV DNA levels, abundant HBV RNA was present in the serum of CHB patients. A series of experiments demonstrated that serum HBV RNA was pregenome RNA (pgRNA) and present in virus-like particles. HBV pgRNA virion levels increased after blocking the reverse transcription activity of HBV DNA polymerase, and decreased after blocking the encapsidation of pgRNA. Furthermore, the presence of HBV pgRNA virion was associated with risk of viral rebound after discontinuation of nucleot(s)ide analogues (NAs) therapy in CHB patients. CONCLUSIONS: Serum HBV RNA was confirmed to be pgRNA present in virus-like particles. HBV pgRNA virions were produced from encapsidated particles in which the pgRNA was non- or partially reverse transcribed. Clinically, HBV pgRNA virion might be a potential biomarker for monitoring safe discontinuation of NA-therapy. LAY SUMMARY: HBV may have another virion form in which the nucleic acid is composed of RNA, not DNA. The level of HBV RNA virion in serum may be associated with risk of HBV viral rebound after withdrawal of treatment, and therefore, a potential predictive biomarker to monitor the safe discontinuation of nucleot(s)ide analogues-therapy.


Asunto(s)
Virus de la Hepatitis B , Animales , ADN Viral , Hepatitis B Crónica , Humanos , Ratones , Octoxinol , Polietilenglicoles , ARN Viral
6.
Environ Sci Technol ; 49(4): 2341-9, 2015 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-25594559

RESUMEN

Using a CH4-based membrane biofilm reactor (MBfR), we studied perchlorate (ClO4(-)) reduction by a biofilm performing anaerobic methane oxidation coupled to denitrification (ANMO-D). We focused on the effects of nitrate (NO3(-)) and nitrite (NO2(-)) surface loadings on ClO4(-) reduction and on the biofilm community's mechanism for ClO4(-) reduction. The ANMO-D biofilm reduced up to 5 mg/L of ClO4(-) to a nondetectable level using CH4 as the only electron donor and carbon source when CH4 delivery was not limiting; NO3(-) was completely reduced as well when its surface loading was ≤ 0.32 g N/m(2)-d. When CH4 delivery was limiting, NO3(-) inhibited ClO4(-) reduction by competing for the scarce electron donor. NO2(-) inhibited ClO4(-) reduction when its surface loading was ≥ 0.10 g N/m(2)-d, probably because of cellular toxicity. Although Archaea were present through all stages, Bacteria dominated the ClO4(-)-reducing ANMO-D biofilm, and gene copies of the particulate methane mono-oxygenase (pMMO) correlated to the increase of respiratory gene copies. These pieces of evidence support that ClO4(-) reduction by the MBfR biofilm involved chlorite (ClO2(-)) dismutation to generate the O2 needed as a cosubstrate for the mono-oxygenation of CH4.


Asunto(s)
Reactores Biológicos , Metano/química , Consorcios Microbianos/fisiología , Percloratos/química , Anaerobiosis , Archaea/genética , Archaea/metabolismo , Bacterias/genética , Bacterias/metabolismo , Biopelículas , Reactores Biológicos/microbiología , Carbono/química , Desnitrificación , Electrones , Regulación de la Expresión Génica , Membranas Artificiales , Metano/metabolismo , Nitratos/metabolismo , Oxidación-Reducción , Percloratos/metabolismo , Permeabilidad , ARN Ribosómico 16S
7.
Onco Targets Ther ; 17: 643-653, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39131904

RESUMEN

Ameloblastoma (AB) is a common odontogenic tumor that develops in the mouth. Despite its benign nature, AB exhibits significant invasiveness leading to tumor metastasis and high postoperative recurrence rates. Studies have shown a relationship between the occurrence and development of various tumors and non-coding RNA (ncRNA). NcRNA, transcribed from the genomes of mammals and other complex organisms, are often products of alternative splicing and processing into smaller products. MicroRNA (miRNA), circular RNA (circRNA), and long non-coding RNA (lncRNA) are the main types of ncRNA. NcRNA play increasingly significant roles in the pathogenesis of human cancers, regulating their occurrence and progression as oncogenes or tumor suppressors. They are involved in tumor development and progression through alternative splicing of pre-mRNA, transcriptional regulation, mRNA stability, protein translation, and chromatin remodeling and modification. The importance of ncRNA in AB has received significant attention in recent years. However, the biological functions and mechanisms of ncRNA in AB remain largely unknown. In this review, we not only explore the functions and roles of ncRNA in AB, but also describe and envision their potential functional roles as biomarkers in AB diagnosis. In particular, we highlight the potential of miR-29a as a molecular marker for diagnosis and therapy. As promising novel therapeutic targets, the biological functions of ncRNA need further study, which is indispensable.

8.
Small ; 9(12): 2171-81, 2013 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-23322550

RESUMEN

In biological environments, nanomaterials associate with proteins forming a protein corona (PC). The PC may alter the nanomaterial's pharmacokinetics and pharmacodynamics, thereby influencing toxicity. Using a label-free mass spectrometry-based proteomics approach, the composition of the PC is examined for a set of nanotubes (NTs) including unmodified and carboxylated single- (SWCNT) and multi-walled carbon nanotubes (MWCNT), polyvinylpyrrolidone (PVP)-coated MWCNT (MWCNT-PVP), and nanoclay. NTs are incubated for 1 h in simulated cell culture conditions, then washed, resuspended in PBS, and assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for their associated PC. To determine those attributes that influence PC formation, the NTs are extensively characterized. NTs had negative zeta potentials in water (SWCNT-COOH < MWCNT-COOH < unmodified NTs) while carboxylation increases their hydrodynamic sizes. All NTs are also found to associate a common subset of proteins including albumin, titin, and apolipoproteins. SWCNT-COOH and MWCNT-COOH are found to bind the greatest number of proteins (181 and 133 respectively) compared to unmodified NTs (<100), suggesting covalent binding to protein amines. Modified NTs bind a number of unique proteins compared to unmodified NTs, implying hydrogen bonding and electrostatic interactions are involved in PC formation. PVP-coating of MWCNT did not influence PC composition, further reinforcing the possibility of hydrogen bonding and electrostatic interactions. No relationships are found between PC composition and corresponding isoelectric point, hydropathy, or aliphatic index, implying minimal roles of hydrophobic interaction and pi-stacking.


Asunto(s)
Nanotubos de Carbono/química , Proteínas/química , Medios de Cultivo , Espectrometría de Masas , Povidona/química , Proteómica
9.
Prenat Diagn ; 33(8): 711-5, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23637079

RESUMEN

OBJECTIVE: The aim of this research was to compare the fetal frontomaxillary facial (FMF) angle between normal and trisomy 21 fetuses at 11(+0) -13(+6) weeks gestation in a Chinese population. METHODS: A prospective observational study was performed that included 640 euploid and 45 trisomy 21 singleton pregnancies undergoing first trimester ultrasound screening between 11 and 13(+6) weeks of gestation. The FMF angle was measured in the midsagittal plane using the standard technique. RESULTS: The fetal mean FMF angle decreased with the increasing crown-rump length (CRL) from 88.6°at a CRL of 45 mm to 78.5° at a CRL of 84 mm (FMF angle = 100.212 - 0.258 × CRL, R(2) = 0.222, p < 0.001). The overall mean FMF angle in the euploid population was 82.9° ± 4.1° and in trisomy 21 cases, 92.3° ± 5.2°. CONCLUSIONS: Fetal FMF angle is affected by gestational age in a Chinese population, although it remains a significant predictor of fetal trisomy 21.


Asunto(s)
Síndrome de Down/diagnóstico por imagen , Síndrome de Down/etnología , Cara/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Ultrasonografía Prenatal/métodos , Adulto , Pueblo Asiatico , Cara/embriología , Femenino , Feto/anatomía & histología , Edad Gestacional , Humanos , Maxilar/embriología , Persona de Mediana Edad , Embarazo , Primer Trimestre del Embarazo/etnología , Segundo Trimestre del Embarazo/etnología , Población Blanca , Adulto Joven
10.
Mol Imaging ; 11(4): 286-300, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22954145

RESUMEN

The purpose of this study was to validate an integrin αvß3-targeted magnetic resonance contrast agent, PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2, for its ability to detect tumor angiogenesis and assess early response to antiangiogenic therapy using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). Integrin αvß3-positive U87 cells and control groups were incubated with fluorescein-labeled cRGD-conjugated dendrimer, and the cellular attachment of the dendrimer was observed. DCE MRI was performed on mice bearing KB xenograft tumors using either PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 or PEG-G3-(Gd-DTPA)6-(cRAD-DTPA)2. DCE MRI was also performed 2 hours after anti-integrin αvß3 monoclonal antibody treatment and after bevacizumab treatment on days 3 and 6t. Using DCE MRI, the 30-minute contrast washout percentage was significantly lower in the cRGD-conjugate injection groups. The enhancement patterns were different between the two contrast injection groups. In the antiangiogenic therapy groups, a rapid increase in 30-minute contrast washout percentage was observed in both the LM609 and bevacizumab treatment groups, and this occurred before there was an observable decrease in tumor size. The integrin αvß3 targeting ability of PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 in vitro and in vivo was demonstrated. The 30-minute contrast washout percentage is a useful parameter for examining tumor angiogenesis and for the early assessment of antiangiogenic treatment response.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Medios de Contraste , Dendrímeros , Gadolinio DTPA , Integrina alfaVbeta3/metabolismo , Imagen por Resonancia Magnética , Neoplasias/irrigación sanguínea , Polietilenglicoles , Inhibidores de la Angiogénesis/farmacología , Animales , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Bevacizumab , Adhesión Celular , Línea Celular Tumoral , Dendrímeros/síntesis química , Gadolinio DTPA/síntesis química , Humanos , Inmunohistoquímica , Masculino , Ratones Desnudos , Neoplasias/diagnóstico por imagen , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Neovascularización Patológica , Polietilenglicoles/síntesis química , ARN Interferente Pequeño/metabolismo , Cintigrafía , Resultado del Tratamiento , Ensayos Antitumor por Modelo de Xenoinjerto
11.
Front Genet ; 13: 1041524, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36457739

RESUMEN

Background: Periodontitis is a chronic inflammatory disease leading to tooth loss in severe cases, and early diagnosis is essential for periodontitis prevention. This study aimed to construct a diagnostic model for periodontitis using a random forest algorithm and an artificial neural network (ANN). Methods: Gene expression data of two large cohorts of patients with periodontitis, GSE10334 and GSE16134, were downloaded from the Gene Expression Omnibus database. We screened for differentially expressed genes in the GSE10334 cohort, identified key periodontitis biomarkers using a Random Forest algorithm, and constructed a classification artificial neural network model, using receiver operating characteristic curves to evaluate its diagnostic utility. Furthermore, patients with periodontitis were classified using a consensus clustering algorithm. The immune infiltration landscape was assessed using CIBERSOFT and single-sample Gene Set Enrichment Analysis. Results: A total of 153 differentially expressed genes were identified, of which 42 were downregulated. We utilized 13 key biomarkers to establish a periodontitis diagnostic model. The model had good predictive performance, with an area under the receiver operative characteristic curve (AUC) of 0.945. The independent cohort (GSE16134) was used to further validate the model's accuracy, showing an area under the receiver operative characteristic curve of 0.900. The proportion of plasma cells was highest in samples from patients with period ontitis, and 13 biomarkers were closely related to immunity. Two molecular subgroups were defined in periodontitis, with one cluster suggesting elevated levels of immune infiltration and immune function. Conclusion: We successfully identified key biomarkers of periodontitis using machine learning and developed a satisfactory diagnostic model. Our model may provide a valuable reference for the prevention and early detection of periodontitis.

12.
Pharmaceuticals (Basel) ; 15(2)2022 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-35215228

RESUMEN

Hand-foot-and-mouth disease (HFMD) caused by human enterovirus A71 (EV-A71) infection has been associated with severe neurological complications. With the lack of an internationally approved antiviral, coupled with a surge in outbreaks globally, EV-A71 has emerged as a neurotropic virus of high clinical importance. Andrographolide has many pharmacological effects including antiviral activity and its derivative, andrographolide sulfonate, has been used in China clinically to treat EV-A71 infections. This study sought to identify novel andrographolide derivatives as EV-A71 inhibitors and elucidate their antiviral mode of action. Using an immunofluorescence-based phenotypic screen, we identified novel EV-A71 inhibitors from a 344-compound library of andrographolide derivatives and validated them with viral plaque assays. Among these hits, ZAF-47, a quinolinoxy-andrographolide, was selected for downstream mechanistic studies. It was found that ZAF-47 acts on EV-A71 post-entry stages and inhibits EV-A71 protein expression. Subsequent luciferase studies confirm that ZAF-47 targets EV-A71 genome RNA replication specifically. Unsuccessful attempts in generating resistant mutants led us to believe a host factor is likely to be involved which coincide with the finding that ZAF-47 exhibits broad-spectrum antiviral activity against other enteroviruses (CV-A16, CV-A6, Echo7, CV-B5, CV-A24 and EV-D68). Furthermore, ZAF-46 and ZAF-47, hits from the screen, were derivatives of the same series containing quinolinoxy and olefin modifications, suggesting that an andrographolide scaffold mounted with these unique moieties could be a potential anti-EV-A71/HFMD strategy.

13.
Chem Commun (Camb) ; 58(95): 13218-13221, 2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36353945

RESUMEN

We present here new amperometric electrodes for the selective and quantitative detection of acetylcholine. The detection was achieved based on the electrodeposition of a carbon electrode with poly(3,4-ethylenedioxythiophene) (PEDOT) followed by the drop-casting of an ionophore-doped poly(vinyl) chloride (PVC) membrane. This work paves the way for future applied research to study neurological disorders.


Asunto(s)
Acetilcolina , Carbono , Cloruro de Polivinilo , Técnicas Electroquímicas , Electrodos , Compuestos Bicíclicos Heterocíclicos con Puentes
14.
Front Immunol ; 12: 763334, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34950140

RESUMEN

Periodontitis (PD) is a common chronic infectious disease. The local inflammatory response in the host may cause the destruction of supporting periodontal tissue. Macrophages play a variety of roles in PD, including regulatory and phagocytosis. Moreover, under the induction of different factors, macrophages polarize and form different functional phenotypes. Among them, M1-type macrophages with proinflammatory functions and M2-type macrophages with anti-inflammatory functions are the most representative, and both of them can regulate the tendency of the immune system to exert proinflammatory or anti-inflammatory functions. M1 and M2 macrophages are involved in the destructive and reparative stages of PD. Due to the complex microenvironment of PD, the dynamic development of PD, and various local mediators, increasing attention has been given to the study of macrophage polarization in PD. This review summarizes the role of macrophage polarization in the development of PD and its research progress.


Asunto(s)
Macrófagos/fisiología , Periodontitis/inmunología , Animales , Polaridad Celular , Citocinas/fisiología , Humanos , Quinasas Janus/fisiología , FN-kappa B/fisiología , Periodontitis/tratamiento farmacológico , Periodontitis/etiología , Periodoncio/inmunología , Factores de Transcripción STAT/fisiología , Transducción de Señal/fisiología
15.
J Agric Food Chem ; 68(19): 5391-5401, 2020 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-32338906

RESUMEN

In this study, a Petri-dish-based double-layer high-throughput screening method was established to improve glucose tolerance of ß-glucosidase Bgl15. Two beneficial mutations were identified, and the joint mutant 2R1 improved the half-maximal inhibitory concentration of glucose from 0.04 to 2.1 M. The crystal structure of 2R1 was subsequently determined at 2.7 Å. Structure analysis revealed that enhancement of glucose tolerance may be due to improved transglycosylation activity made possible by a hydrophobic binding site for glucose as an acceptor and more stringent control of a putative water channel. To further ameliorate the application potential of the enzyme, it was engineered to increase the half-life at 50 °C from 0.8 h (Bgl15) to 180 h (mutant 5R1). Furthermore, supplementation of 5R1 to the cellulase cocktail significantly improved glucose production from pretreated sugar cane bagasse by 38%. Consequently, this study provided an efficient approach to enhance glucose tolerance and generated a promising catalyst for cellulose saccharification.


Asunto(s)
Celulosa/metabolismo , Glucosa/metabolismo , beta-Glucosidasa/química , beta-Glucosidasa/metabolismo , Catálisis , Celulosa/química , Estabilidad de Enzimas , Glucosa/química , Hidrólisis , Cinética , Mutación , Ingeniería de Proteínas , beta-Glucosidasa/genética
16.
Water Res ; 160: 148-157, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31136848

RESUMEN

Chromate is considered to be a toxic contaminant because of its potential to harm animal and human health. In this study, polypyrrole/calcium rectorite clay composites (PPy/Ca-REC composites) were prepared as a potential adsorbent, via in situ polymerization of pyrrole monomer for adsorption of Cr(VI) from aqueous solution. The XRD results indicated that the clay sheets were exfoliated in the prepared composites. SEM results showed good dispersion of the PPy on the clay sheets. The adsorption of Cr(VI) onto the PPy/Ca-REC adsorbent was highly pH-dependent, and the removal efficiency by PPy/Ca-REC composites was much higher than the PPy homopolymer. Adsorption kinetics followed a pseudo-second-order kinetic model with an equilibrium reached within 30-180 min. The adsorption isotherm data were fitted well by the Langmuir isotherm model with the maximum adsorption capacity of 714.29-833.33 mg/g at 25-45 °C. The PPy/Ca-REC composites could be regenerated and reused for three consecutive adsorption-desorption cycles without loss of the original removal efficiency for Cr(VI) removal. Furthermore, the selective adsorption of Cr(VI) was demonstrated in binary adsorption systems with coexisting ions. The mechanisms of Cr(VI) removal containing electrostatic interactions, ionic interaction as well as reduction of Cr(VI) to Cr(III), which could be observed by the XPS results.


Asunto(s)
Cromo , Contaminantes Químicos del Agua , Adsorción , Silicatos de Aluminio , Animales , Calcio , Concentración de Iones de Hidrógeno , Cinética , Minerales , Polímeros , Pirroles
17.
Lab Chip ; 19(12): 2089-2095, 2019 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-31111136

RESUMEN

Natural colorants, which impart a vivid color to food and add additional health benefits, are favored over synthetic colorants; however, their applications are limited by their low solubility in water and low stability. Here, we develop a versatile microfluidic strategy to incorporate natural colorants in shellac nanoparticles with controlled physicochemical properties. The rapid mixing in the microfluidic channels ensures that the mixing time is shorter than the aggregation time, thus providing control over the co-precipitation of the colorant and the polymer. By introducing molecular interactions, colorant nanoaggregates are efficiently embedded in the polymer matrix, forming hierarchical colorant-loaded nanoparticles. The colorant-loaded nanoparticles dispersed in water are transparent and stable over a wide pH range and their polymer matrix also provides a favorable microenvironment that greatly improves the shelf life of the colorants. The improved solubility, stability and bioavailability of the natural colorants suggest that shellac nanoparticles are ideal carriers and the stable, transparent dispersions of biocompatible colorant-loaded nanoparticles in water are well-suited for the development of functional foods, such as natural color drinks.


Asunto(s)
Bebidas/análisis , Materiales Biocompatibles/química , Aditivos Alimentarios/química , Colorantes de Alimentos/química , Técnicas Analíticas Microfluídicas , Nanopartículas/química , Color , Técnicas Analíticas Microfluídicas/instrumentación
18.
Artículo en Inglés | MEDLINE | ID: mdl-27863136

RESUMEN

The understanding of nano-bio interactions is deemed essential in the design, application, and safe handling of nanomaterials. Proper characterization of the intrinsic physicochemical properties, including their size, surface charge, shape, and functionalization, is needed to consider the fate or impact of nanomaterials in biological and environmental systems. The characterizations of their interactions with surrounding chemical species are often hindered by the complexity of biological or environmental systems, and the drastically different surface physicochemical properties among a large population of nanomaterials. The complexity of these interactions is also due to the diverse ligands of different chemical properties present in most biomacromolecules, and multiple conformations they can assume at different conditions to minimize their conformational free energy. Often these interactions are collectively determined by multiple physical or chemical forces, including electrostatic forces, hydrogen bonding, and hydrophobic forces, and calls for multidimensional characterization strategies, both experimentally and computationally. Through these characterizations, the understanding of the roles surface physicochemical properties of nanomaterials and their surface interactions with biomacromolecules can play in their applications in biomedical and environmental fields can be obtained. To quantitatively decipher these physicochemical surface interactions, computational methods, including physical, statistical, and pharmacokinetic models, can be used for either analyses of large amounts of experimental characterization data, or theoretical prediction of the interactions, and consequent biological behavior in the body after administration. These computational methods include molecular dynamics simulation, structure-activity relationship models such as biological surface adsorption index, and physiologically-based pharmacokinetic models. WIREs Nanomed Nanobiotechnol 2017, 9:e1440. doi: 10.1002/wnan.1440 For further resources related to this article, please visit the WIREs website.


Asunto(s)
Materiales Biocompatibles , Nanoestructuras , Propiedades de Superficie , Animales , Investigación Biomédica , Humanos , Ratones , Modelos Teóricos , Simulación de Dinámica Molecular , Relación Estructura-Actividad
19.
J Phys Chem B ; 121(27): 6673-6684, 2017 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-28614660

RESUMEN

In situ small-, ultrasmall-, and wide-angle X-ray scattering measurements were performed to investigate the structural evolution of crystalline lamellae and cavities as a function of deformation ratio during tensile deformation of isothermally crystallized poly(ε-caprolactone). The cavities were modeled as cylinder-shaped objects which are oriented along the stretching direction and randomly distributed in the samples, and their dimensions were evaluated by direct model fitting of scattering patterns. At small deformations, the orientation of these cavities at the onset of cavity formation was related to the isothermal crystallization temperature. Upon further stretching, the cavities were found to cluster in the interfibrillar regions at moderate strains where the long spacing of the newly developed lamellae along the stretching direction remained essentially constant. At large orientations, the cooperative deformational behavior mediated via slippage of fibrils was evidenced, the extent of which depended on the cavity number, which could be traced back to the significantly different coupling forces imposed by chains connecting adjacent fibrils. Furthermore, wide-angle X-ray scattering results revealed that a fraction of the polymer chains with their orientation perpendicular to the stretching direction were still preserved even at large macroscopic strains.


Asunto(s)
Poliésteres/química , Temperatura , Rastreo Diferencial de Calorimetría , Cristalización , Dispersión del Ángulo Pequeño , Difracción de Rayos X
20.
J Chromatogr A ; 1347: 49-55, 2014 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-24792699

RESUMEN

We have previously found that addition of like-charged media in a refolding solution can greatly enhance the refolding of pure proteins by suppressing protein aggregation. Herein, negatively charged mono-sized microspheres with sulfonic groups were fabricated to explore the facilitating effect of like-charged media on the refolding of enhanced green fluorescent protein (EGFP) expressed as inclusion bodies (IBs). A sequential polymer-tentacle grafting and sulfonate modification strategy was developed to increase the charge density of mono-sized poly(glycidyl methacrylate) (pGMA) beads (2.4µm). Namely, GMA was first grafted onto the beads by grafting polymerization to form poly(GMA) tentacles on the pGMA beads, and then the epoxy groups on the tentacles were converted into sulfonic groups by modification with sodium sulfite. By this fabrication strategy, the charge density of the beads reached 793µmol/g, about 2.8 times higher than that modified without prior grafting of the pGMA beads (285µmol/g). The negatively charged beads of different charge densities were used for facilitating the refolding of like-charged EGFP from IBs. The refolding yield as well as refolding rate increased with increasing charge density. The anti-aggregation effects of urea and like-charged microspheres were synergetic. In addition, partial purification of EGFP was achieved because the ion-exchange adsorption led to 52% removal of positively charged contaminant proteins in the refolded solution. Finally, reusability of the tentacle beads was demonstrated by repetitive EGFP refolding and recovery cycles.


Asunto(s)
Proteínas Fluorescentes Verdes/aislamiento & purificación , Cuerpos de Inclusión/química , Ácidos Polimetacrílicos , Adsorción , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Cuerpos de Inclusión/metabolismo , Intercambio Iónico , Microesferas , Replegamiento Proteico
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