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1.
Mater Sci Eng C Mater Biol Appl ; 128: 112261, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474820

RESUMO

Glioblastoma multiforme (GBM) remains a major cause of mortality because treatments are precluded by to the limited transport and penetration of chemotherapeutics across the blood-brain barrier. Pitavastatin (PTV) is a hydrophobic Food and Drug Administration (FDA)-approved anticholesterolemic agent with reported anti-GBM activity. In the present study, we encapsulate PTV in silica-coated polymeric micelles (SiO2 PMs) surface-modified with the cyclic peptide Arg-Gly-Asp-Phe-Val (cRGDfV) that actively targets the αvß3 integrin overexpressed in the BBB endothelium and GBM. A central composite design is utilized to optimize the preparation process and improve the drug encapsulation ratio from 131 to 780 µg/mL. The silica shell provides full colloidal stability upon extreme dilution and enables a better control of the release kinetics in vitro with 28% of the cargo released after 12 h. Furthermore, SiO2 PMs show excellent compatibility and are internalized by human BBB endothelial cells, astrocytes and pericytes, as shown by confocal laser scanning fluorescence microscopy and flow cytometry. Finally, the anticancer efficacy is assessed in a pediatric patient-derived glioma cell line expressing high levels of the integrin subunits αv, ß3 and ß5. This PTV-loaded nanocarrier triggers apoptosis by reducing the mRNA level of anti-apoptotic genes NF-kß, IL-6, BIRC1 and BIRC5 by 89%, 33%, 81% and 63%, respectively, and the cell viability by >60%. Overall, our results suggest the potential of these hybrid nanocarriers for the targeted therapy of GBM and other tumors overexpressing integrin receptors.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/tratamento farmacológico , Linhagem Celular Tumoral , Criança , Células Endoteliais , Glioblastoma/tratamento farmacológico , Humanos , Integrinas , Micelas , Dióxido de Silício
2.
Mater Sci Eng C Mater Biol Appl ; 128: 112272, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474831

RESUMO

Integrating multiple materials with different functionalities in a single nanostructure enables advances in many scientific and technological applications. However, such highly sophisticated nanomaterials usually require complex synthesis processes that complicate their preparation in a sustainable and industrially feasible manner. Herein, we designed a simple general method to grow a mesoporous silica shell onto any combination of hydrophilic nanoparticle cores. The synthetic strategy, based on the adjustment of the key parameters of the sol-gel process for the silica shell formation, allows for the embedment of single, double, and triple inorganic nanoparticles within the same shell, as well as the size-control of the obtained nanocomposites. No additional interfacial adhesive layer is required on the nanoparticle surfaces for the embedding process. Adopting this approach, electrostatically stabilized, small-sized (from 4 to 15 nm) CeO2, Fe3O4, Gd2O3, NaYF4, Au, and Ag cores were used to test the methodology. The mean diameter of the resulting nanocomposites could be as low as 55 nm, with high monodispersity. These are very feasible sizes for biological intervention, and we further observed increased nanoparticle stability in physiological environments. As a demonstration of their increased activity as a result of this, the antioxidant activity of CeO2 cores was enhanced when in core-shell form. Remarkably, the method is conducted entirely at room temperature, atmospheric conditions, and in aqueous solvent with the use of ethanol as co-solvent. These facile and even "green" synthesis conditions favor scalability and easy preparation of multicomponent nanocomposite libraries with standard laboratory glassware and simple benchtop chemistry, through this sustainable and cost-effective fabrication process.


Assuntos
Nanocompostos , Nanopartículas , Dióxido de Silício
3.
Mater Sci Eng C Mater Biol Appl ; 128: 112274, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474833

RESUMO

Corneal neovascularization (CNV) is one of the main factors that induce blindness worldwide. To effectively inhibit CNV, a novel nanohybrid has been developed by incorporating anti-VEGF bevacizumab (BEV)-loaded mesoporous silica nanoparticles (BEV@MSN) into the thermogel matrix with anti-inflammation cyclosporine A (CsA) (BEV@MSN-CsA@Thermogel). This nanohybrid regulates the in vitro release of both bevacizumab and cyclosporine A in a sustainable way for up to four weeks to enhance CNV inhibition through the synergistic anti-VEGF and anti-inflammation. The carrier materials (i.e. silica and thermogel) in this nanohybrid do not show any cytotoxicity to human Tenon's fibroblasts, corneal epithelial cells and corneal endothelial cells. BEV@MSN-CsA@Thermogel effectively prevents proliferation, migration, and tube-like structure formation of human umbilical vein endothelial cells. Moreover, subconjunctival injection of BEV@MSN-CsA@Thermogel significantly inhibits corneal neovascularization in terms of the CNV area, the new vessel length, the corneal opaque area, the corneal inflammation and abnormal fibrosis in a rabbit model. This nanohybrid is thus a promising alternative for effective CNV treatment.


Assuntos
Neovascularização da Córnea , Preparações Farmacêuticas , Animais , Bevacizumab/farmacologia , Neovascularização da Córnea/tratamento farmacológico , Modelos Animais de Doenças , Células Endoteliais da Veia Umbilical Humana , Humanos , Coelhos , Dióxido de Silício , Fator A de Crescimento do Endotélio Vascular
4.
Mater Sci Eng C Mater Biol Appl ; 128: 112316, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474867

RESUMO

To develop a nanoparticle-based vaccine against necrotic enteritis, a chimeric antigen (rNA) consisting of the main antigens of Clostridium perfringens, NetB, and Alpha toxin, was prepared. Then, the rNA molecules were loaded onto the functionalized mesoporous silica nanoparticles (MSNPs) using physical adsorption or covalent conjugation methods. The characterization of synthesized nanoparticles was performed by scanning electron microscopy, dynamic light scattering, zeta potential measurement, Fourier transform infrared spectroscopy, and thermogravimetry techniques. The results revealed that the spherical nanoparticles with an average diameter of 90 ±â€¯12 nm and suitable surface chemistries are prepared. MSNPs-based formulations did not show any significant toxicity on the chicken embryo fibroblast cells. The results of the challenge experiments using subcutaneous or oral administration of the as-prepared formulations in the animal model showed that the as-prepared nanosystems, similar to those formulated with a commercial adjuvant (Montanide), present stronger humoral immune responses as compared to that of the free proteins. It was also indicated that the best protection is obtained in groups vaccinated with MSNPs-based nanovaccine, especially those who orally received covalently conjugated nanovaccine candidates. These results recommend that the MSNPs-based formulated chimeric proteinous vaccine candidates can be considered as an effective immunizing system for the oral vaccination of poultry against gastrointestinal infectious diseases.


Assuntos
Toxinas Bacterianas , Infecções por Clostridium , Enterite , Nanopartículas , Doenças das Aves Domésticas , Vacinas , Animais , Anticorpos Antibacterianos , Embrião de Galinha , Galinhas , Infecções por Clostridium/prevenção & controle , Infecções por Clostridium/veterinária , Enterite/prevenção & controle , Enterite/veterinária , Doenças das Aves Domésticas/prevenção & controle , Dióxido de Silício
5.
Talanta ; 235: 122790, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517648

RESUMO

Abnormal glycosylation of exosomal proteins is related to many diseases. However, there is still a lack of convenient and easy methods for the determination of exosomal glycoproteins. In this work, a ratiometric electrochemical sensor based on the recognition of glycoproteins by boronic acid and core-shell nanoparticles of silica-silver (SiO2@Ag) amplified signals was developed for the highly sensitive detection of exosomal glycoproteins. The CD63 aptamer-SiO2-N-(2-((2-aminoethyl)disulfanyl)ethyl) ferrocene carboxamide (FcNHSSNH2) probe was first connected to graphene oxide-cucurbit [7] (GO-CB [7]) modified GCE through host-guest recognition. The CD63 aptamer was employed for the specific capture of exosomes, and the FcNHSSNH2 molecule was used as the internal reference signal of the sensor. The mercaptophenylboronic acid (MPBA) of MPBA-SiO2@Ag probe was used for the identification of exosomes surface glycoproteins. SiO2 nanoparticle has a large specific surface area, which can load a large amount of silver nanoparticles (AgNPs) for electrochemical signal amplification. The results were expressed as the current ratio of AgNPs and FcNHSSNH2. The introduction of the internal reference molecule FcNHSSNH2 could effectively reduce the measurement error caused by the different DNA density of the substrate, and further improve the sensitivity and accuracy of the detection. Under the optimal experimental conditions, this sensor allowed the sensitive detection of exosomal glycoproteins in the range of 4.2 × 102 to 4.2 × 108 particles/µL with a limit of detection (LOD) of 368 particles/µL. Furthermore, the ratiometric electrochemical sensor could be employed for the detection of exosomal glycoproteins in human serum samples, which has a good clinical application prospect.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Técnicas Eletroquímicas , Glicoproteínas , Limite de Detecção , Dióxido de Silício , Prata
6.
J Clin Pediatr Dent ; 45(4): 259-264, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34534309

RESUMO

OBJECTIVE: To determine the retentive force of three glass-ionomer luting cements used with prefabricated primary zirconium crowns (PPZCs) and to assess whether the retentive force was dependent on cementation material or different PPZCs brands. STUDY DESIGN: Four mandibular right second molar PPZCs were selected, one each from four manufacturers-NuSmile®ZR, Sprig Crowns, Cheng Crowns and Kinder Krowns. Silicone impressions of the outer surface of crowns were taken; stone dies prepared and reduced to fit the corresponding brand. 24 alginate impressions of each die obtained and filled with core buildup flowable composite. 96 composite tooth-replicas thus achieved were divided into four groups and further categorized into three subgroups of eight samples based on luting cements used - BioCem, FujiCEM®2 and KetacCem. Samples were thermocycled, placed in artificial saliva for one week followed by assessment of retentive force for crown dislodgment and failure mode. RESULTS: Data was statistically evaluated using two-way ANOVA, HSD (P <0.05). KetacCem had the lowest retentive force while BioCem showed comparatively higher value to FujiCEM®2. Adhesive failure modes were predominant with cement mainly adhering to crown's internal surface. CONCLUSIONS: Resin-based GI cements offered superior retention than conventional GI cements for PPZCs and retentive force was dependent on cement type.


Assuntos
Retenção em Prótese Dentária , Zircônio , Resinas Acrílicas , Cimentação , Coroas , Cimentos Dentários , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Cimentos de Resina , Dióxido de Silício
7.
Anal Chim Acta ; 1179: 338806, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34535268

RESUMO

We present a temperature-responsive spin column using an all-aqueous eluent. The method is intended as a simple sample preparation method for protein removal from serum, which is required for serum drug analysis. As packing materials for the spin column, we prepared two types of silica beads via surface-initiated radical polymerization. The large beads (diameter, 40-63 µm) were grafted with a temperature-responsive cationic copolymer, poly(N-isopropylacrylamide-co-N,N-dimethylaminopropyl acrylamide-co-n-butyl methacrylate) (P(NIPAAm-co-DMAPAAm-co-BMA)), and the small beads (diameter, 5 µm) were grafted with a temperature-responsive hydrophobic copolymer, P(NIPAAm-co-BMA). The beads were packed into the spin column as a double layer: P(NIPAAm-co-BMA) silica beads on the bottom and P(NIPAAm-co-DMAPAAm-co-BMA) silica beads on the top. The sample purification efficacy of the prepared spin column was evaluated on a model sample analyte (the antifungal drug voriconazole mixed with blood serum proteins). At 40 °C, the serum proteins and voriconazole were adsorbed on the prepared spin column via hydrophobic and electrostatic interactions. When the temperature was decreased to 4 °C, the adsorbed voriconazole was eluted from the column with the pure water eluent, while the serum proteins remained in the column. This temperature-responsive spin column realizes sample preparation simply by changing the temperature.


Assuntos
Polímeros , Dióxido de Silício , Interações Hidrofóbicas e Hidrofílicas , Temperatura , Água
8.
Se Pu ; 39(10): 1137-1145, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34505436

RESUMO

Aristolochic acids (AAs), which is commonly found in Aristolochia and Asarum plants, has been widely used in several traditional medicine practices due to their anti-inflammatory, anti-malarial, and anti-hyperglycemic activities. Recently, researchers have found a “decisive link” between liver cancer and aristolochic acid after analyzing a large number of liver cancer samples around the world. Therefore, a highly sensitive and selective method is required for the analysis of AAs in traditional Chinese medicines (TCM). For the determination of AAs in TCM, pretreatment is indispensable because in actual TCM samples, AAs is present in trace amounts and the complex matrix exerts interference. In the past decades, molecularly imprinted polymers (MIPs) have attracted considerable attention as an alternative for the trace analysis in complicated matrices. In this study, MIP-coated SiO2 nanoparticles (SiO2@MIP NPs) was prepared for the determination of aristolochic acid by surface molecular imprinting using aristolochic acid Ⅰ (AAI ) as the template molecule, 2-vinylpyridine (VPY) as the functional monomer, and ethyleneglycol dimethacrylate (EGDMA) as the cross-linking agent. Core-shell-structure SiO2@MIP NPs were obtained by modifying vinyl groups on the surface of SiO2 NPs, coating MIPs films onto the silica surface via selective polymerization, and final extraction of template AAI and generation of the recognition site. To find a suitable functional monomer for the best imprinting effect, the interaction between the template and the functional monomers, including acrylic acid (AA), methyl acrylic acid (MAA), 2-vinyl pyridine (VPY), acrylamide (AM), and methylacrylamide (MAM) was investigated. Electrostatic interaction between AAI and VPY resulted in the maximum decrease in absorbance of AAI at 250 nm. Therefore, VPY was chosen for the preparation of MIP. The morphological and physical properties of the MIPs were characterized by transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric analysis, and N2 adsorption and desorption surface analysis. TEM images showed that SiO2 NPs were monodispersed with diameter of about 200 nm. The clear core-shell structure of SiO2@MIP NPs was observed, and the thickness of MIPs coating was about 35 nm. The FT-IR spectra of SiO2 NPs, vinyl group modified SiO2 and SiO2@MIP NPs revealed that the vinyl group and organic MIP layer were successfully modified at SiO2 sequentially. The results of thermogravimetric analysis were consistent with the FT-IR data for different SiO2 NPs. The nitrogen gas adsorption-desorption experiments showed that SiO2@MIP NPs and non-imprinted polymer (SiO2@NIP NPs) have the same pore volumes, while the surface area and pore size of MIPs were slightly larger than those of NIPs. Therefore, the difference in adsorption between SiO2@MIP NPs and SiO2@NIP NPs resulted from the imprinted sites on the MIP surface, rather than the difference in their surface areas. The adsorption properties of SiO2@MIP NPs were demonstrated by kinetic, isothermal, and selective adsorption experiments. The results of these experiments displayed that SiO2@MIP NPs reached adsorption equilibrium within a short period (120 s) and possessed a much higher rebinding ability than SiO2@NIP NPs. To verify the selectivity of SiO2@MIP NPs for AAI, three structural analogues (viz. tanshinone ⅡA, 2-methoxy-5-nitrophenol, and benzoic acid) were selected. The results showed that the binding capacity of SiO2@MIP NPs was much higher than those of these analogues. SiO2@MIP NPs have high adsorption capacity (5.74 mg/g), high imprinting factor (4.9), good selectivity coefficient (2.3-6.6) towards the structural analogues. SiO2@MIP NPs was used as an adsorbent and combined with HPLC for the selective separation of AAI in TCM. The recoveries of Kebia trifoliate samples spiked with three levels of AAI (0.3, 0.5, and 1.0 μg/mL) ranged from 73% to 83%. The results suggested that the proposed SiO2@MIP NPs could be used for selective enrichment of AAI from real complex TCM samples.


Assuntos
Ácidos Aristolóquicos , Impressão Molecular , Nanopartículas , Adsorção , Polímeros Molecularmente Impressos , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier
9.
J Hazard Mater ; 416: 125913, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492847

RESUMO

Deep degradation of chlorophenols (CPs) into safe and ecofriendly cyclohexanol during catalytic hydrodechlorination (HDC), shows important practical significance and attractive prospect in the treatment of wastewater containing chlorophenols. An efficient Rh-La/SiO2 catalyst was developed, by employing La as promoter. The presence of La in catalyst promoted catalytic performance of HDC significantly. Characterization results revealed that the interaction occurred between Rh and La in Rh-La/SiO2 catalyst. This interaction accompanied with the high dispersion and finely particle size of active Rh, and generation of abundant Rh sites neighboring La atom. Kinetic study illustrated that Rh-La(1:1)/SiO2 catalyst possessed the fastest kinetic constants, and minimized the apparent activation energies of 4-CP, phenol and cyclohexanone greatly. Complete degradation of 4-CP with a very high yield of cyclohexanol (> 98%) can be achieved at room temperature, making Rh-La(1:1)/SiO2 catalyst to be a promising candidate for deep degradation of CPs during HDC and other Rh catalyzed hydrogenation reactions.


Assuntos
Clorofenóis , Catálise , Hidrogenação , Dióxido de Silício , Águas Residuárias
10.
J Hazard Mater ; 416: 126216, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492973

RESUMO

Thermal treatment of municipal solid waste incineration fly ash (FA) is an effective method to detoxicate FA and produce secondary material with good utilization properties, but the high temperature induced migration of carbon, chlorine, and catalytic metals from FA to flue gases can result in a considerable reformation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Herein, two typical fly ashes were thermally cotreated with sewage sludge (SS), respectively, and the decomposition and reformation of PCDD/Fs were systematically investigated. Thermal treatment effectively decomposed PCDD/Fs in all samples to a low level well meeting the reutilization criterion of 50 ng WHO-TEQ g-1. Cleavage of the oxygen bridge was identified as the primary decomposition pathway. Compared to mono-treating FA, cotreating FA with SS resulted in a better CaO-Al2O3-SiO2 ternary system for vitrification and effectively suppressed the reformation of PCDD/Fs in off-gases with inhibition efficiencies up to 96%. Based on the variation of chemical speciation of N, P, and S in SS after thermal treatment, SS appeared to be a S-N-containing inhibitor which passivated catalytic metals to suppress PCDD/Fs synthesis. The better suppression on de novo pathway than on chlorophenol-route identified by monitoring PCDD/F-fingerprints evolution further verified the suppression mechanism of passivating catalytic metals.


Assuntos
Benzofuranos , Dibenzodioxinas Policloradas , Cinza de Carvão , Dibenzofuranos , Dibenzofuranos Policlorados , Incineração , Dibenzodioxinas Policloradas/análise , Esgotos , Dióxido de Silício , Resíduos Sólidos/análise
11.
Talanta ; 235: 122737, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517605

RESUMO

As an important post-translational modification of proteins, phosphorylation plays a key role in regulating a variety of complicated biological reactions. Owing to the fact that phosphopeptides are low abundant and the ionization efficiency could be suppressed in mass spectroscopic detection, highly efficient and selective enrichment methods are essential to identify protein phosphorylation by mass spectrometry. Here, we develop novel titanium oxide coated core shell mesoporous silica (CSMS@TiO2) nanocomposites for enrichment of phosphopeptides with simultaneous exclusion of massive proteins. The CSMS@TiO2 nanocomposites have essential features, including uniform 1.0 µm diameter, 120 nm thick shell, 7.0 nm mesopores perpendicular to the surface, large surface area of 77 m2/g and pore volume of 0.15 cm3/g, therefore can greatly improve the sensitivity for identifying phosphopeptides by capillary electrophoresis-mass spectrometry. The proposed CSMS@TiO2 nanocomposites are applied for analysis of ß-casein tryptic digest and bovine serum albumin (BSA) protein mixture, respectively. The results show that the number of phosphopeptides detected is tremendously increased by using CSMS@TiO2 nanocomposite, proving selectively enriching phosphopeptides due to the size-exclusive and specific interaction of the TiO2-modified mesopores. The enrichment of the phosphopeptides is achieved even for the digests at very low concentration of ß-casein (1 fmol/µL). This research would open up a promising idea to utilize mesoporous materials in peptidomics analysis.


Assuntos
Fosfopeptídeos , Titânio , Animais , Caseínas , Bovinos , Dióxido de Silício , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
12.
Talanta ; 235: 122743, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517611

RESUMO

The analysis of contaminants in migration of food contact material (FCMs) is an urgent demand for food safety. In this study, melamine and formaldehyde in melamine kitchenware were selectively analyzed by surface-enhanced Raman scattering (SERS) via aptamer/derivatization-based membrane assembly. The membrane assembly was designed by simple filtration of Ag nanoparticles-decorated "stellate" silicon dioxide (SiO2/Ag) and composites of reduced graphene oxide and Ag nanoparticles (rGO/Ag) functioned with specific reagents. High selectivity can be realized by melamine aptamer and derivatization reagent of formaldehyde, respectively. The relative standard deviations (RSDs) of melamine and formaldehyde analysis for 11 replicate measurements, 14 consecutive days and 25 batches are less than 6.0 %, which shows excellent repeatability and reproducibility. After the method was validated, the limits of detection (LOD) for melamine and formaldehyde are 0.15 mg/L and 0.21 mg/L, respectively. The developed method was applied to determine the content of melamine and formaldehyde in migration of melamine kitchenware with low relative errors (less than 5.3 %) compared to chromatographic results. The recoveries of melamine and formaldehyde for migrations of melamine kitchenware are 91.2-110.0 % and 94.0-106.0 % with RSDs in range of 1.8-8.3 % and 4.7-9.1 %, respectively. The method proposed a new concept of convenient, portable and reliable strategy for analysis of melamine and formaldehyde in migration from FCMs.


Assuntos
Nanopartículas Metálicas , Análise Espectral Raman , Formaldeído , Reprodutibilidade dos Testes , Dióxido de Silício , Prata , Triazinas
13.
Talanta ; 235: 122754, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517622

RESUMO

Chiral covalent organic frameworks (CCOFs) have potential application in enantioseparation due to their advantages, such as large surface area, abundant chiral recognition sites and good chemical stability in organic solvents. However, the application of CCOFs in high performance liquid chromatography (HPLC) for enantioseparation has been rarely reported because of the shortcomings of CCOFs, such as light weight, irregular shape, and wide particle size distribution. In order to overcome the above shortcomings, a one-pot synthetic method was adopted to prepare a core-shell composite (ß-CD-COF@SiO2) via the growth of chiral ß-CD COF on the surface of amino-functionalized SiO2 microspheres. The as-prepared ß-CD-COF@SiO2 microspheres were used as a stationary phase for HPLC enantioseparation. The resolution ability of the ß-CD-COF@SiO2-packed column toward various chiral compounds was investigated using n-hexane/isopropanol as the mobile phase. The results show that the chiral ß-CD-COF@SiO2-packed column exhibited excellent chiral recognition ability for 24 pairs of chiral compounds with good reproducibility. These successful applications indicate that the preparation of the chiral COFs@SiO2 core-shell microspheres as a novel stationary phase for enantioseparation has good application prospects in HPLC.


Assuntos
Estruturas Metalorgânicas , Dióxido de Silício , Cromatografia Líquida de Alta Pressão , Microesferas , Reprodutibilidade dos Testes
14.
Talanta ; 235: 122772, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517631

RESUMO

In many cases of in-situ or point-of-care testing (POCT), the single pursuit of good detection performance cannot meet the testing requirements, and thus no-wash testing has become one of the most effective methods to develop sustainable biosensing assay, providing more convenient operation procedures and shorting the detection time. Herein, a disposable POC biosensing assay was prepared based on the RGB color detector software on the smartphone and the peroxide-like activity of gold nanoparticles (Au NPs) for aflatoxin B1 (AFB1) sensitive detection. Using syringe filters for a simple physical separation procedure can easily realize washing free detection, which is superior to most biosensing assays with cumbersome detection procedures. The syringe filters with 200 nm pore diameter could only pass through small Au NPs (30 nm) while the large-sized SiO2 nanoparticles (300 nm) was blocked on the membrane. In this work, Au NPs utilized their inherent peroxidase-like activity to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to ox-TMB under acidic conditions, which results in blue color in aqueous solution. The color change due to different antigen concentrations was quantitatively determined by measuring the color intensity with a smartphone and the RGB color detector. By measuring the color intensity, it was known that the linear concentration range of the biosensing assay was 100 fg mL-1 to 50 ng mL-1, and the detection limit of AFB1 was 33 fg mL-1 (S/N = 3). Additionally, the designed biosensing assay exhibited excellent selectivity, storage stability and reproducibility. More importantly, the innovation of detecting and analyzing technology is the outstanding advantage of the biosensing assay, providing a more flexible and convenient strategy for some other small molecule analysis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Aflatoxina B1/análise , Colorimetria , Ouro , Peróxido de Hidrogênio , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito , Reprodutibilidade dos Testes , Dióxido de Silício
15.
Talanta ; 235: 122795, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517653

RESUMO

In order to solve the problems of using a large proportion of acetonitrile on the hydrophilic interaction liquid chromatography (HILIC) columns that was not environmentally friendly, and the poor acid and base resistance of traditional bonded silica columns, we reported a novel stationary phase of Au nanoparticles (Au NPs) covalently bonded to ionic liquid (ILs) bridged periodic mesoporous organosilicas (PMO) hydrophilic microspheres (PMO-ILs-Au NPs) for per aqueous liquid chromatography (PALC). The PMO hydrophilic microspheres were prepared by condensation of 1,3-bis(trimethoxysilylpropyl)imidazoliumchloride and 1, 2-Bis (triethoxysilyl) ethane and then modified with Au NPs the surface. The obtained materials were characterized by elemental analysis, FT-IR spectra, scanning electron microscope and transmission electron microscopy. The retention behavior was evaluated by investigating the effect of various chromatographic factors on the retention of different types of solutes. The retention mechanism of the stationary phases in PALC was a mixed type of anion-exchange and hydrophobic interaction. Compared with C18-SiO2 column, the acid and base resistance of the stationary phase were greatly improved. Compared with the HILIC column and C18 column, some hydrophilic compounds such as six organic acids and eight biogenic amines were baseline separated with the enhanced resolution of the PMO-ILs-Au NPs column under the PALC mode. The efficiency of the new column was significantly higher than that of the HILIC column. Furthermore, the analysis of PALC-triple quadrupole mass spectrometry was developed for simultaneous detection of eight biogenic amines. This method could improve detection efficiency, save reagent and reduce environmental pollution. PALC as a green chromatography analytical method was suitable for the replacement of HILIC.


Assuntos
Líquidos Iônicos , Nanopartículas Metálicas , Aminas Biogênicas , Cromatografia Líquida , Ouro , Interações Hidrofóbicas e Hidrofílicas , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier
16.
J Biomed Nanotechnol ; 17(8): 1679-1689, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544544

RESUMO

We established a self-decomposable SiO2 encapsulated mitochondrial targeting short peptide SS31 drug loading system (SiO2@SS31) to determine its nano-sustained release characteristics in eukaryotic cells. We explored the protection of SiO2@SS31 on the 661W cells after oxidative injury by H2O2. After the drug loading, we detected the morphology of SiO2@SS31 by transmission electron microscopy (TEM). Moreover, high-pressure liquid chromatography (HPLC) was used to determine the drug capacity and encapsulation efficiency of the nanoparticles. Then, the release curve in vitro was drawn. The 661W cells were cultured in vitro to allow the detection of cytotoxicity by the MTT assay. The SS31loaded nanoscale microspheres labeled with fluorescein isothiocyanate (SiO2@FITC-SS31) were prepared, and their sustained release effect was detected with intracellular endocytosis, using confocal microscopy and flow cytometry. Within 15 days, the SiO2@SS31 nanoparticles were completely decomposed and simultaneously released the SS31 peptide in deionized water and normal saline. Nonetheless, the process was faster in simulated body fluid and serum. The MTT assay suggested that SiO2@SS31 has sustained protection compared with SS31 in the 661W cells at 48 h. Flow cytometry proved SiO2@FITC-SS31 could maintain a high level and last longer after 24 h. The SS31 peptide, which has excellent medical application prospects, can be slowly and continuously released from self-decomposable SiO2 and targeted to concentrate on mitochondria.


Assuntos
Células Eucarióticas , Peróxido de Hidrogênio , Mitocôndrias , Peptídeos , Dióxido de Silício
17.
Nanoscale ; 13(31): 13318-13327, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34477738

RESUMO

Investigation of the self-assembly of peptides is critically important to clarify certain biophysical phenomena, fulfill some biological functions, and construct functional materials. However, it is still a challenge to precisely predict the self-assembled structures of peptides because of their complicated driving forces and various assembling pathways. In this work, to elucidate the effects of noncovalent interactions including hydrogen bonding, molecular geometry, and hydrophobic and electrostatic interactions on the peptide self-assembly, a series of asymmetric bolaamphiphilic short peptides consisting of Ac-EI3K-NH2 (EI3K), Ac-EI4K-NH2 (EI4K), Ac-KI3E-NH2 (KI3E) and Ac-KI4E-NH2 (KI4E) were designed and their self-assembling behaviors at different solution pH values were investigated systematically. The peptides self-assembled into twisted nanofibers under most conditions except for EI4K in a strongly alkaline solution and KI4E under a strongly acidic condition, in which they self-assembled into nanotubes via helical monolayer nanosheet intermediates. In particular, KI4E nanotubes are formed under acidic conditions, and its diameters are ∼500 nm much greater than most of the self-assembled structures from bolaamphiphilic peptides. Moreover, reversible morphological transition between the nanotubes and twisted nanofibers was observed with the change in solution pH. Such tunable self-assembled structures and switchable surface properties of the asymmetric bolaamphiphilic short-peptides allow them to be used as templates to construct advanced materials. Silica and titania nanomaterials faithful to the peptide templates in morphology were prepared at ambient temperature. This work clearly elucidates the effects of noncovalent interactions on the peptide self-assembly and also provides new insights into the design and preparation of complicated inorganic materials from tunable organic templates.


Assuntos
Nanoestruturas , Dióxido de Silício , Interações Hidrofóbicas e Hidrofílicas , Peptídeos , Titânio
18.
Anal Chim Acta ; 1178: 338824, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482870

RESUMO

A simple and highly efficient method for the determination of highly toxic arsenic species using non-covalently aminated silica is proposed. The polyamines including poly(hexamethyleneguanidine), poly(4,9-dioxadodecane-1,12-guanidine), hexadimethrine, and poly(diallyldimethylammonium) were tested as silica modifiers. The prepared adsorbents allow effective preconcentration of anionic species of arsenic from aqueous solutions. It was found that As(V) can be quantitatively extracted from solutions at pH 4.5-7.0 by the anion exchange mechanism in less than 5 min, while neutral at this pH As(III) was not adsorbed at these conditions. A reaction with 2,3-dimercapto-1-propanesulphonic acid, which resulted in the formation of the negatively charged complex of As(III) with adsorbents was used for its quantitative extraction from solutions with a pH of 3.5-6.5. A system of two cartridges filled with poly(diallyldimethylammonium) modified silica and the on-line reaction of As(III) with 2,3-dimercapto-1-propanesulphonic acid proceeding between the cartridges was used for separate preconcentration and determination of As(V) and As(III) at pH 5. The proposed method was used for four-year monitoring of natural water pollution by arsenic in the area of residence of the indigenous peoples of Tyva Republic (Russia).


Assuntos
Arsênio , Concentração de Íons de Hidrogênio , Poliaminas , Dióxido de Silício , Água
19.
Enzyme Microb Technol ; 150: 109864, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489023

RESUMO

Encapsulated enzymes are stable under various conditions and used in enzyme therapy, catalysis, and biosensors. The capsules are often inspired by structures from nature such as viral capsids, DNA motifs and diatom frustules. They are based on inorganic minerals as well as soft or polymeric materials, or even a combination of these. The choice of material influences the enzyme loading and response to heat, pH and presence of proteases. This review provides a comparison of enzyme encapsulation based on these different principles with a focus on materials inspired by nature.


Assuntos
Biomimética , Polímeros , Biopolímeros , Cápsulas , Catálise , Dióxido de Silício
20.
Anal Chim Acta ; 1180: 338860, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538337

RESUMO

Mesopores silica nanotubes (MSNTs)-based chemical sensors for the rapid detection and of highly selective Fe2+ ions have been prepared. The novel nanosensors were prepared via immobilization of 1,10-phenanthroline-5-amine (PA) and bathophenanthroline (BP) onto the MSNTs. The resultant PA and BP sensors display high sensitivity for detection the Fe2+ ions in tap water, river water, sea water, two units in simple cycle power station, and biological samples. More interestingly, upon meeting ultra-trace amount of Fe2+ ions, a red complex appears at once. Color changes can be seen from the naked eye and tracked with a smartphone or spectrophotometric techniques. The response time that is necessary to achieve a stable signal was less than 15 s. The Univariate (Univar) calibration technique had been utilized for the determination of figures of merits. The detection limit obtained from the digital image analysis was 19 ppb (7.04 × 10-7 M) for Fe2+ ions, while the obtained from the spectrophotometric method was 6.7 ppb (2.48 × 10-7 M). Therefore, the two sensors had been successfully used in the determination of Fe2+ in several real samples with high sensitivity and selectivity. In addition, they can be used as a simple, rapid, and portable method to detect and quantify the pre rust in any cooler system.


Assuntos
Nanotubos , Águas Residuárias , Colorimetria , Íons , Dióxido de Silício
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