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1.
J Biomed Nanotechnol ; 17(3): 439-446, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33875078

RESUMEN

As it is difficult to prevent secondary nucleation and agglomeration during the preparation of core-shell silica microspheres, these issues have been successfully resolved in this study using template-dissolution-induced redeposition. The non-porous particles are transformed into core-shell silica microspheres (CSSMs) in the presence of cetyltrimethylammonium bromide and octyltrimethylammonium bromide under basic conditions. The shell thickness and pore sizes of the CSSMs are controlled by adjusting the etching time and molar ratio of the template, respectively. The CSSMs are modified using octadecyltrimethylammonium chloride to separate the mixture of alkyl benzenes, and a high column separation efficiency is achieved within two minutes. The CSSMs are used for the separation and analysis of proteins and the digests of bovine serum albumin. The chromatographic column packed with core-shell particles affords a significantly higher separation efficiency than the commercial column. Therefore, as a chromatographic stationary phase, these core-shell particles can potentially be used for the fast separation of proteins, small solutes, and complex samples.


Asunto(s)
Albúmina Sérica Bovina , Dióxido de Silicio , Cromatografía Líquida de Alta Presión , Microesferas , Porosidad
2.
Int J Mol Sci ; 22(5)2021 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-33800363

RESUMEN

Quantitative and robust serology assays are critical measurements underpinning global COVID-19 response to diagnostic, surveillance, and vaccine development. Here, we report a proof-of-concept approach for the development of quantitative, multiplexed flow cytometry-based serological and neutralization assays. The serology assays test the IgG and IgM against both the full-length spike antigens and the receptor binding domain (RBD) of the spike antigen. Benchmarking against an RBD-specific SARS-CoV IgG reference standard, the anti-SARS-CoV-2 RBD antibody titer was quantified in the range of 37.6 µg/mL to 31.0 ng/mL. The quantitative assays are highly specific with no correlative cross-reactivity with the spike proteins of MERS, SARS1, OC43 and HKU1 viruses. We further demonstrated good correlation between anti-RBD antibody titers and neutralizing antibody titers. The suite of serology and neutralization assays help to improve measurement confidence and are complementary and foundational for clinical and epidemiologic studies.


Asunto(s)
/métodos , /sangre , Pruebas de Neutralización/métodos , Pruebas de Neutralización/normas , /inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Reacciones Cruzadas , Citometría de Flujo/métodos , Fluorescencia , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Microesferas , Receptores Virales/química , Receptores Virales/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología
3.
Sensors (Basel) ; 21(5)2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33807789

RESUMEN

The detection of viruses using imaging techniques is challenging because of the weak scattering of light generated by the targets of sizes in the nanometer range. The system we have developed overcomes the light scattering problems by utilizing antibody-coated microbeads of higher index of refraction that can specifically bind with viruses and increase the acceptance angle. Using the new technology, we have developed a portable, cost-effective, and field-deployable platform for the rapid quantification of HIV-1 viral load for point-of-care (POC) settings. The system combines microfluidics with a wide field of view lensless imaging technology. Highly specific antibodies are functionalized to a glass slide inside a microchip to capture HIV-1 virions. The captured virions are then bound by antibody-conjugated microbeads, which have a higher refraction index. The microbeads-HIV-1 virions complexes generate diffraction patterns that are detected with a custom-built imaging setup and rapidly and accurately quantified by computational analysis. This platform technology enables fast nanoscale virus imaging and quantification from biological samples and thus can play a significant role in the detection and management of viral diseases.


Asunto(s)
VIH-1 , Microesferas , Sistemas de Atención de Punto , Refractometría , Carga Viral
4.
Langmuir ; 37(14): 4137-4146, 2021 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-33813823

RESUMEN

Hydroxyapatite (HA) is the main inorganic component of human bones and teeth. It has good biocompatibility and bioactivity, which promotes its good application prospects in the field of bone drug carriers. In this study, tetraethylenepentamine-graphene (rGO-TEPA)/CaCO3:HA composite microspheres were prepared via microwave hydrothermal synthesis using rGO-TEPA/CaCO3 solid microspheres as intermediates. Furthermore, the incompletely transformed CaCO3 was removed by soaking in a citric acid buffer to obtain rGO-TEPA/HA hollow composite microspheres. The two types of as-prepared composite microspheres exhibited sea urchin-like structures, large BET surface areas, and good dispersibility. Mouse preosteoblast cells (MC3T3-E1) were used for in vitro cytotoxicity experiments. The in vitro cell viability test showed that the two composite drug carriers exhibited noncytotoxicity. Moreover, the doxorubicin (DOX) loading and releasing investigations revealed that the two types of prepared carriers had mild storage-release behaviors and good pH responsiveness. Hence, these rGO-TEPA/HA hollow microspheres have promising applications as bone drug carriers.


Asunto(s)
Materiales Biomiméticos , Huesos/metabolismo , Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Durapatita , Grafito , Microesferas , Erizos de Mar , Animales , Huesos/citología , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/farmacología , Etilenodiaminas , Concentración de Iones de Hidrógeno , Ratones , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Células Madre/efectos de los fármacos
5.
Talanta ; 229: 122272, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33838774

RESUMEN

Aberrant transcription factors (TFs) activities are closely related to the occurrence and development of various diseases. Herein, we presented a fluorescence-encoded microsphere-based approach for TFs detection coupling with common DNA footprinting assay. Target TFs specifically bound the binding sites of double-stranded DNA (dsDNA) probes which were conjugated to microspheres. Thus, the probes were protected from being hydrolyzed by exonuclease III (Exo III). Afterwards, biotins labeled on the probes reacted with streptavidin-phycoerythrin (SA-PE) to produce fluorescent signal; however, in the absence of target TFs, the dsDNA probes would be hydrolyzed by Exo III resulting in biotins falling off and thus fluorescence signal was not generated. This strategy can be used to detect nuclear factor-kappa B p50 (NF-κB p50) with a detection limit of 0.2 nM. The steric hindrance of microspheres overcome the disadvantage of Exo III that can nibble into the protein-bound DNA region. Meanwhile, the fluorescent label of microsphere was specific to each TF, enabling multiplex detection could be achieved by changing specific protein binding site of corresponding dsDNA probe. This method has been successfully applied for simultaneous detection of NF-κB p50, AP-1 and CREB in nuclear extract isolated from HeLa cells stimulated or unstimulated by TNF-α, showing great potential for biomedical researches and precise disease diagnosis.


Asunto(s)
Técnicas Biosensibles , Microesferas , ADN/genética , Sondas de ADN/genética , Exodesoxirribonucleasas , Células HeLa , Humanos , Límite de Detección , Subunidad p50 de NF-kappa B
6.
Int J Mol Sci ; 22(6)2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33801871

RESUMEN

Recently, nano- and micro-particulate systems have been widely utilized to deliver pharmaceutical compounds to achieve enhanced therapeutic effects and reduced side effects. Poly (DL-lactide-co-glycolide) (PLGA), as one of the biodegradable polyesters, has been widely used to fabricate particulate systems because of advantages including controlled and sustained release, biodegradability, and biocompatibility. However, PLGA is known for low encapsulation efficiency (%) and insufficient controlled release of water-soluble drugs. It would result in fluctuation in the plasma levels and unexpected side effects of drugs. Therefore, the purpose of this work was to develop microcapsules loaded with alginate-coated chitosan that can increase the encapsulation efficiency of the hydrophilic drug while exhibiting a controlled and sustained release profile with reduced initial burst release. The encapsulation of nanoparticles in PLGA microcapsules was done by the emulsion solvent evaporation method. The encapsulation of nanoparticles in PLGA microcapsules was confirmed by scanning electron microscopy and confocal microscopy. The release profile of hydrophilic drugs can further be altered by the chitosan coating. The chitosan coating onto alginate exhibited a less initial burst release and sustained release of the hydrophilic drug. In addition, the encapsulation of alginate nanoparticles and alginate nanoparticles coated with chitosan in PLGA microcapsules was shown to enhance the encapsulation efficiency of a hydrophilic drug. Based on the results, this delivery system could be a promising platform for the high encapsulation efficiency and sustained release with reduced initial burst release of the hydrophilic drug.


Asunto(s)
Preparaciones de Acción Retardada/farmacocinética , Nanopartículas/química , Preparaciones Farmacéuticas/metabolismo , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/farmacocinética , Alginatos/química , Biodegradación Ambiental , Cápsulas , Quitosano/química , Preparaciones de Acción Retardada/química , Portadores de Fármacos , Liberación de Fármacos , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Microesferas , Nanopartículas/ultraestructura , Tamaño de la Partícula , Preparaciones Farmacéuticas/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química
7.
Carbohydr Polym ; 259: 117501, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33673978

RESUMEN

The study's purpose was to fabricate a 3-D porous scaffold, in which chitosan was coated onto the pore wall of polycaprolactone (PCL) scaffolds as a bioactive agent to maximize the cell recognition signals, to improve the osteoconductivity of the scaffolds. The pppporogen leaching technique has been modified and used in the fabrication process, comprising of the coating of chitosan over the porogen followed by transferring of coating to the pore wall of the PCL scaffold. The cytotoxicity and hemolysis results indicated chitosan's presence over the surface of the scaffold's pore walls has significantly enhanced its biocompatibility. Scaffolds coated with 2.5 %(w/v) chitosan shows 6.74 % increase in porosity and 207.96 % upsurge in mechanical strength, compared to PCL scaffolds. The Gene-expression also proves the study groups of scaffolds show the minimal osteogenic expression. Therefore, chitosan coating over the scaffold's pore wall's surface opens an unconventional approach for tissue engineering applications.


Asunto(s)
Quitosano/química , Poliésteres/química , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Fuerza Compresiva , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Hemólisis , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Microesferas , Osteogénesis/efectos de los fármacos , Parafina/química , Porosidad , Ratas
8.
Molecules ; 26(5)2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33669152

RESUMEN

The FDA (U.S. Food and Drug Administration) has approved only a negligible number of poly(lactide-co-glycolide) (PLGA)-based microsphere formulations, indicating the difficulty in developing a PLGA microsphere. A thorough understanding of microsphere formulations is essential to meet the challenge of developing innovative or generic microspheres. In this study, the key factors, especially the key process factors of the marketed PLGA microspheres, were revealed for the first time via a reverse engineering study on Vivitrol® and verified by the development of a generic naltrexone-loaded microsphere (GNM). Qualitative and quantitative similarity with Vivitrol®, in terms of inactive ingredients, was accomplished by the determination of PLGA. Physicochemical characterization of Vivitrol® helped to identify the critical process parameters in each manufacturing step. After being prepared according to the process parameters revealed by reverse engineering, the GNM demonstrated similarity to Vivitrol® in terms of quality attributes and in vitro release (f2 = 65.3). The research on the development of bioequivalent microspheres based on the similar technology of Vivitrol® will benefit the development of other generic or innovative microspheres.


Asunto(s)
Microesferas , Naltrexona/química , Poliglactina 910/química , Tamaño de la Partícula , Propiedades de Superficie
9.
Carbohydr Polym ; 260: 117770, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712128

RESUMEN

Chitin-derived three-dimensional nanomaterials has tremendous potential in pesticide residue analysis as an attractive green substitute for toxic solvents. The work presented herein focuses on constructing the environmentally friendly nitrogen-containing chitin-derived carbon microspheres (N-CCMP) for the efficient adsorption of neonicotinoid pesticides (NPs) including acetamiprid, clothianidin, imidacloprid and thiamethoxam. The N-CCMP displayed hierarchical porous structure, uniform size distribution, and excellent specific surface area of 680.8 m2 g-1. The N-CCMP with N-heterocyclic ring structure and surface oxygen functional groups exhibited good affinity to NPs, which was beneficial for the rapid adsorption. Then, the N-CCMP were utilized as sorbent in extraction of NP residues. Under the optimum conditions, the relative recoveries in water and juice sample were in the range of 85 %-116 % and 74 %-108 %, with relative standard deviations (RSDs) of 0.1 %∼5.2 % and 0.7 %∼5.2 %, respectively. The extraction performance of N-CCMP were still over 80 % after 5 times of reuse.


Asunto(s)
Carbono/química , Quitina/química , Microesferas , Neonicotinoides/química , Nitrógeno/química , Residuos de Plaguicidas/química , Adsorción , Cromatografía Líquida de Alta Presión , Agua Dulce/análisis , Jugos de Frutas y Vegetales/análisis , Neonicotinoides/análisis , Residuos de Plaguicidas/análisis , Porosidad , Espectrometría de Masas en Tándem
10.
Carbohydr Polym ; 260: 117811, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712156

RESUMEN

Novel pectin/poly(m-phenylenediamine) (P/PmPDA) microspheres with different content of PmPDA were prepared by assembling PmPDA on the surface of pectin microsphere. The successful preparation was confirmed by the results of Fourier Transform Infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis. Compared with pectin microsphere, the Pb2+ adsorption performance of P/PmPDA microspheres was significantly improved. The results of batch adsorption experiments were in good agreement with the Langmuir isotherm model for Pb2+ adsorption, indicating the adsorption was monolayer. The maximum adsorption capacity of Pb2+ was found to be 390.9 mg/g. The kinetic adsorption process was well described by the pseudo-second-order model and chemical adsorption dominated the adsorption process. The potential mechanisms of Pb2+ adsorption were speculated as ion exchange and chelation, which were supported by X-ray photoelectron spectroscopy (XPS). The P/PmPDA microspheres showed good recyclability after five adsorption/desorption cycles. All these results indicated the potential of P/PmPDA microspheres for removing Pb2+.


Asunto(s)
Plomo/química , Microesferas , Pectinas/química , Fenilendiaminas/química , Adsorción , Concentración de Iones de Hidrógeno , Iones/química , Cinética , Plomo/aislamiento & purificación , Espectroscopía de Fotoelectrones , Propiedades de Superficie
11.
J Chromatogr A ; 1642: 462000, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33684874

RESUMEN

The anti-citrillinated protein antibody (ACPA) plays an important role in early diagnosis of rheumatoid arthritis (RA), and is usually detected by using cyclic citrullinated peptide (CCP) as antigen. The ACPA against CCP test is usually performed utilizing enzyme-linked immunosorbent assay (ELISA), but the ELISA is expensive and time-consuming. Here, latex particle-enhanced turbidimetric immunoassay (LTIA) based on CCP-immobilized latex bead was proposed for fast measurements of ACPA of RA patients. CCP-immobilized latex bead was fabricated through three methods, including direct coupling, overall coupling and layer by layer coupling. According to the optimized experiments, layer-by-layer coupling was the best method with advantages of time-saving, simple operation and good repeatability. In addition, a spacer arm of appropriate length between latex beads and CCP could avoid stereoscopic obstacles and make ACPA closer to CCP. The CCP-immobilized latex bead based on layer by layer coupling (CCP-LB-LLC) was used for assembling the homemade kit, which was applied in fast measurements of ACPA through LTIA. The homemade kit possessed a low limit of detection (0.2 U/mL) and an acceptable the batch-to-batch reproducibility. In addition, the homemade kit can be stored at 4 °C for at least one month. When used to detect 20 clinical samples, the results of homemade kit were consistent with commercial ELISA. Furthermore, LTIA based on the homemade kit was simpler and cheaper than ELISA. These results demonstrated that the homemade kit could be useful for diagnosis of RA patients.


Asunto(s)
Autoanticuerpos/análisis , Citrulinación/inmunología , Inmunoturbidimetría/métodos , Látex/química , Microesferas , Péptidos Cíclicos/química , Animales , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/inmunología , Autoanticuerpos/inmunología , Bovinos , Humanos , Nefelometría y Turbidimetría , Tamaño de la Partícula , Polisorbatos/química , Poliestirenos/química , Reproducibilidad de los Resultados , Albúmina Sérica Bovina/química , Electricidad Estática , Factores de Tiempo
12.
J Chromatogr A ; 1642: 462009, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33721811

RESUMEN

Monodisperse restricted-access media bi-functional monomers with molecularly imprinted polymers (RAM-MIPs) were constructed using surface-initiated atom transfer radical polymerization. They were used as solid-phase extraction (SPE) adsorbents to enrich sarafloxacin (SAR) residues from egg samples, and influences on their performance were investigated. Optimum synthesis of RAM-MIPs was achieved by combining a bi-functional monomer (4-vinylpyridine-co-methacrylic acid, 1:3) with an 8:1:32:8 ratio of a template molecule, cross-linker, and restricted-access functional monomer. The SAR imprinting factor of RAM-MIPs was 6.05 and the selectivity coefficient between SAR and other fluoroquinolones was 1.86-2.64. Compared with traditional MIPs, the RAM-MIPs showed better SAR enrichment and selectivity during extraction of a complex protein-containing solution. Empty SPE cartridges were filled with RAM-MIP microspheres as SPE adsorbents. The limit of quantitation for SAR was 4.23 ng g-1 (signal-to-noise ratio = 10) and the mean SAR recovery from spiked egg samples was 94.0-101.3%. Intra-day and inter-day relative standard deviations were 1.1-9% and 1.5-3.3%, respectively.


Asunto(s)
Ciprofloxacino/análogos & derivados , Extracción en Fase Sólida/métodos , Adsorción , Ciprofloxacino/aislamiento & purificación , Reactivos de Enlaces Cruzados/química , Cinética , Metacrilatos/química , Microesferas , Impresión Molecular , Polimerizacion
13.
AAPS PharmSciTech ; 22(3): 119, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33782794

RESUMEN

Despite the importance of drug release testing of parenteral depot formulations, the current in vitro methods still require ameliorations in biorelevance. We have investigated here the use of muscle tissue components to better mimic the intramuscular administration. For convenient handling, muscle tissue was used in form of a freeze-dried powder, and a reproducible process of incorporation of tested microspheres to an assembly of muscle tissue of standardized dimensions was successfully developed. Microspheres were prepared from various grades of poly(lactic-co-glycolic acid) (PLGA) or ethyl cellulose, entrapping flurbiprofen, lidocaine, or risperidone. The deposition of microspheres in the muscle tissue or addition of only isolated lipids into the medium accelerated the release rate of all model drugs from microspheres prepared from ester-terminated PLGA grades and ethyl cellulose, however, not from the acid-terminated PLGA grades. The addition of lipids into the release medium increased the solubility of all model drugs; nonetheless, also interactions of the lipids with the polymer matrix (ad- and absorption) might be responsible for the faster drug release. As the in vivo drug release from implants is also often faster than in simple buffers in vitro, these findings suggest that interactions with the tissue lipids may play an important role in these still unexplained observations.


Asunto(s)
Preparaciones de Acción Retardada , Infusiones Parenterales , Músculos/metabolismo , Animales , Celulosa/análogos & derivados , Portadores de Fármacos , Composición de Medicamentos , Liberación de Fármacos , Excipientes , Flurbiprofeno/administración & dosificación , Técnicas In Vitro , Lidocaína/administración & dosificación , Microesferas , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Risperidona/administración & dosificación , Porcinos
15.
Cell Prolif ; 54(3): e13004, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33543561

RESUMEN

OBJECTIVES: Endoscopic submucosal dissection (ESD), a preferential approach for early oesophageal neoplasms, inevitably results in oesophageal strictures in patients. Clinical use of glucocorticoids through submucosal injection is beneficial for inhibiting oesophageal stricture following injury; however, it also has limitations, such as dose loss and perforation. Hence, alternatives to glucocorticoid therapy should be developed. METHODS: A novel porous composite scaffold, ChCo-TAMS, composed of chitosan, collagen-I and triamcinolone acetonide (TA) loaded into poly (lactic-co-glycolic) acid (PLGA) microspheres (TAMS), was successfully constructed and subjected to biological testing to ameliorate oesophageal ESD-related stenosis. RESULTS: The synthesized biomaterials displayed unique properties in inhibiting the activation of macrophages, chemokine-mediated cell recruitment and fibrogenesis of fibroblasts. Further application of the scaffolds in the rat dermal defect and porcine oesophageal ESD model showed that these novel scaffolds played a robust role in inhibiting wound contracture and oesophageal ESD strictures. CONCLUSIONS: The developed composite scaffolds provide a promising clinical medical device for the prevention of post-operative oesophageal stricture.


Asunto(s)
Quitosano/farmacología , Colágeno/efectos de los fármacos , Constricción Patológica/patología , Neoplasias Esofágicas/tratamiento farmacológico , Estenosis Esofágica/tratamiento farmacológico , Animales , Materiales Biocompatibles/metabolismo , Quitosano/metabolismo , Colágeno/metabolismo , Constricción Patológica/etiología , Neoplasias Esofágicas/patología , Estenosis Esofágica/prevención & control , Ratones , Microesferas , Triamcinolona/metabolismo , Triamcinolona Acetonida/administración & dosificación , Triamcinolona Acetonida/farmacología
16.
J Chromatogr A ; 1640: 461948, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33561708

RESUMEN

Fast-throughput and cost reduction of current purification platforms are becoming increasing requests during antibody manufacture. The macroporous-matrix absorbents have presented extensive potentiality in improving operational throughput during purification of macromolecule. And meanwhile the peptide ligand has become a promising alternative to recombinant protein ligands for cost reduction of chromatographic purification. Therefore, here we designed a functionalized microspheres resin with both macroporous matrix of polymerized glycidyl methacrylate and ethylene glycol dimethacrylate (PGMA-EDMA) and peptide ligand of hexapeptide (FYEILH). In order to circumvent the steric effect of peptides and amplify the binding sites on macroporous matrix, the peptide ligand was coupled on a liner PGMA polymer brushes grafted on microspheres. Comparing to the conventional agarose-matrix resin and the general peptide-grafted microspheres, the functionalized microspheres presented excellent permeability and high capacity to rapid loading hIgG by maintaining a stable level of dynamic binding capacity at fast flow rate above 110 column volume per hour (cv/h) and very short residence time below 0.5 min. Such functionalized microspheres provide a facile and broadly applicable strategy to develop the attractive candidate for rapid and cost-reduced purification of antibody.


Asunto(s)
Anticuerpos Monoclonales/aislamiento & purificación , Inmunoglobulina G/aislamiento & purificación , Microesferas , Péptidos/química , Polímeros/química , Adsorción , Animales , Células CHO , Cromatografía , Cricetulus , Difusión , Humanos , Ligandos , Permeabilidad , Polimerizacion , Porosidad , Dominios Proteicos , Proteínas Recombinantes/química , Resinas Sintéticas/química , Sefarosa/química , Albúmina Sérica Bovina/química , Proteína Estafilocócica A/química , Propiedades de Superficie
17.
J Chromatogr A ; 1640: 461967, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582513

RESUMEN

In this work, for the first time five amine-ligands including mono-amine, di-amine, tri-amine, secondary and tertiary amine, were functionalized on mesoporous micro-silicas and developed as stationary phases for hydrophilic interaction liquid chromatography (HILIC). The investigations about the retention mechanisms, effects of different chromatographic conditions and stability were systematically conducted. Three kinds of polar and hydrophilic compounds (saccharides, sulfonamides, nucleosides and nucleobases) were selected as probe molecules to evaluate their separation performances. Among the five stationary phases, only aminopropyl-bonded silica has already gained wide developments and applications. Whereas, there are no related researches about the other four to be utilized as separation media. By a series of chromatographic evaluations, the results revealed the other four mesoporous micro-silica materials functionalized with di-amine, tri-amine, secondary and tertiary amine, had great potential to be explored as novel stationary phases of HILIC. Particularly, the two stationary phases functionalized with di-amine and tri-amine exhibited outstanding separation and retention abilities. This work offered some insights on the understanding of retention in HILIC mode and provided us possibility to explore other amine-based HILIC stationary phases.


Asunto(s)
Aminas/química , Cromatografía Liquida/métodos , Interacciones Hidrofóbicas e Hidrofílicas , Microesferas , Dióxido de Silicio/química , Acetonitrilos/química , Adsorción , Tampones (Química) , Concentración de Iones de Hidrógeno , Ligandos , Nucleósidos/química , Nucleósidos/aislamiento & purificación , Sulfonamidas/aislamiento & purificación , Temperatura
18.
Int J Nanomedicine ; 16: 1157-1174, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33623380

RESUMEN

Introduction: Candida albicans is a major opportunistic pathogen that causes a wide range of human infections. Currently available therapeutic agents are limited for treating these fungal infections due to multidrug resistance as well as their nonbiodegradability, poor biocompatibility and toxicity. In order to battle these limitations, we have synthesized a polymeric system as microcarriers to deliver the antifungal drug. The objective of the present study was to immobilize MgO/CuO nanocomposite and nystatin-loaded MgO/CuO nanocomposites in nontoxic, nonimmunogenic, biodegradable and biocompatible sodium alginate microspheres for the first time. Materials and Methods: Nanoparticle-loaded sodium alginate microspheres were prepared by ionotropic gelation technique using calcium chloride as a cross-linker. Synthesized microspheres were characterized using standard characterization techniques and were evaluated for biological activity against MDR strain of C. albicans. Results: Characterization of microspheres by Fourier-transform infrared spectroscopy confirmed loading of Nys-MgO/CuO NPs, scanning electron microscopy (SEM) revealed rough spherical beads with a highly porous surface having an average size in the range of 8-10 µm. X-ray diffraction (XRD) analyzed its semicrystalline structure. Entrapment efficiency of Nys-MgO/CuO NPs was 80% and release kinetic study revealed sustained and prolonged release of drug in pH 5.5. Flow cytometry analysis showed yeast cell death caused by Nys-MgO/CuO MS exhibits late apoptotic features. In cytotoxicity assay 5-14 mg of microspheres did not cause hemolysis. Microspheres reduced virulence traits of C. albicans such as germ tube and biofilm formation were compromised at concentration of 5 mg/mL. Antimicrobial assessment results revealed a pronounced inhibitory effect against C. albicans. Conclusion: The in vitro experiments have shown promising results based on good stability, Nys-MgO/CuO NP-encapsulated microspheres can be used as a prolonged controlled release system against MDR pathogenic C. albicans.


Asunto(s)
Alginatos/química , Candida albicans/patogenicidad , Cobre/química , Resistencia a Múltiples Medicamentos , Óxido de Magnesio/química , Microesferas , Nanocompuestos/química , Nistatina/farmacología , Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Liberación de Fármacos , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Humanos , Cinética , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Fenotipo , Espectroscopía Infrarroja por Transformada de Fourier , Virulencia/efectos de los fármacos , Factores de Virulencia/metabolismo , Difracción de Rayos X
19.
Nat Commun ; 12(1): 1116, 2021 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-33602911

RESUMEN

Microscale propulsion impacts a diverse array of fields ranging from biology and ecology to health applications, such as infection, fertility, drug delivery, and microsurgery. However, propulsion in such viscous drag-dominated fluid environments is highly constrained, with time-reversal and geometric symmetries ruling out entire classes of propulsion. Here, we report the spontaneous symmetry-breaking propulsion of rotating spherical microparticles within non-Newtonian fluids. While symmetry analysis suggests that propulsion is not possible along the fore-aft directions, we demonstrate the existence of two equal and opposite propulsion states along the sphere's rotation axis. We propose and experimentally corroborate a propulsion mechanism for these spherical microparticles, the simplest microswimmers to date, arising from nonlinear viscoelastic effects in rotating flows similar to the rod-climbing effect. Similar possibilities of spontaneous symmetry-breaking could be used to circumvent other restrictions on propulsion, revising notions of microrobotic design and control, drug delivery, microscale pumping, and locomotion of microorganisms.


Asunto(s)
Elasticidad , Fenómenos Magnéticos , Microesferas , Dinámicas no Lineales , Resinas Acrílicas/química , Humanos , Mucinas/química , Mucinas/ultraestructura , Reología , Viscosidad
20.
J Chromatogr A ; 1641: 462006, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33640807

RESUMEN

Bio-based and low-cost hybrid polyvinyl alcohol (PVA) and gelatin (Gel) hydrophilic macromolecular complex coated microspheres were prepared based on one-pot process, characterized, and applied as novel sorbent materials for the purification of trace aminoglycosides from complex matrices. PVA acts as a "rigid" component in the hybrid complex to enhance its mechanical properties, while Gel's "flexible" role is to improve the swelling properties of the hybrid complex in water. It is shown that hybrid PVA/Gel-functionalized sorbents are more efficient than the respective PVA or Gel sorbents since the presence of Gel increases the material selectivity for aminoglycosides, which is due to the specific interactions occurring between the targets and amino acid residues in the hybrid materials. Under the optimum conditions, material preparation and pretreatment processes were entirely carried out in single water system without toxic organic solvent. The detection limit (LOD) of spectinomycin, kanamycin, streptomycin and dihydrostreptomycin in honey were 0.811, 0.303, 0.168, 0.045 µg⋅kg-1 respectively. Linearity was obtained in the range of 20 to 2000 ug⋅kg-1, relative recovery yield up to 84.1-111.7% were obtained and matrix effect of all four aminoglycosides was within 100.8-107.6%. Intra-day and inter-day precision under four spiking levels (5, 200, 500 and 1000 ug⋅kg-1) were less than 10.9% (n=6) and 13.6% (n=3) respectively. In addition, the sorbents exhibited excellent reusability even after six recycles. This work demonstrates the potential of bio-based and low-cost hybrid polymer extraction platforms as promising bonded phase alternatives, in which eco-friendly and natural-based polymers can be used to improve the material selectivity and are conducive to the realization of "green chemistry".


Asunto(s)
Aminoglicósidos/aislamiento & purificación , Alcohol Polivinílico/química , Dióxido de Silicio/química , Adsorción , Calibración , Geles , Miel/análisis , Límite de Detección , Microesferas , Estándares de Referencia , Reproducibilidad de los Resultados , Extracción en Fase Sólida
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