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1.
Int J Nanomedicine ; 17: 17-29, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35023917

RESUMO

Background: Compared with the healthy condition, osteoporotic bone defects are often accompanied by poor osteogenesis and excessive reactive oxygen species (ROS), which pose serious challenges to bone augmentation and repair by normal resorbable guided bone regeneration (GBR) membrane. Purpose: Polaprezinc (PZ) was loaded into polycaprolactone/gelatin (PG) hybrid electrospun nanofibers to fabricate a GBR membrane with antioxidant and osteogenesis ability. Methods: A series of physicochemical characterization were performed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and water contact angle measurement. In addition to membrane degradation and PZ release detection, membranes were tested for cell viability, differentiation, and protein expression in MC3T3-E1 cells by CCK8, alkaline phosphatase activity, mineralization, and Western blotting assays. The membrane osteogenic capacity in cranial bone defects was studied by micro-CT in vivo. Results: PZ was successfully doped into the PCL/GEL nanofibers to form a hydrophilic GBR membrane. The cumulative release of PZ was closely related to the membrane degradation behavior. PG/0.4%PZ membranes produced the best protective effect on cell proliferation/differentiation under oxidative stress microenvironment; however, the PG/0.8%PZ membrane was cytotoxic. Western blotting demonstrated that the PZ-loaded membrane upregulated the Nrf2/HO-1/SOD1 signaling molecules in a concentration-dependent manner. In addition, micro-CT results showed an abundant formation of new bones in the PG/0.4%PZ group compared to the PG group. Conclusion: PZ-loaded degradable PG membranes (especially PG/0.4%PZ) have great potential to accelerate bone regeneration in oxidative stress-related diseases.


Assuntos
Nanofibras , Osteoporose , Antioxidantes/farmacologia , Regeneração Óssea , Carnosina/análogos & derivados , Proliferação de Células , Humanos , Compostos Organometálicos , Osteogênese , Osteoporose/tratamento farmacológico , Poliésteres , Tecidos Suporte , Compostos de Zinco
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 269: 120702, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34922287

RESUMO

Urgent identification of COVID-19 in infected patients is highly important nowadays. Förster or fluorescence resonance energy transfer (FRET) is a powerful and sensitive method for nanosensing applications, and quantum dots are essential materials in FRET-based nanosensors. The QDs are conjugated to DNA or RNA and used in many applications. Therefore, in the present study, novel fluorescence DNA-conjugated CdTe/ZnS quantum dots nanoprobe designed for detection of Covid-19 after extracting their RNA from saliva of hesitant people. For achieving this purpose, the water-soluble CdTe/ZnS QDs-DNA prepared via replacing the thioglycolic acid (TGA) on the surface of QDs with capture DNA (thiolated DNA) throw a ligand-exchange method. Subsequently, by adding the different concentrations of complementary (target DNA) in a mixture of quencher DNA (BHQ2-labeled DNA) and the QDs-DNA conjugates at different conditions, sandwiched hybrids were formed. The results showed that the fluorescence intensity was decreased with increasing the concentration of target DNA (as a positive control). The linear equation and regression (Y = 40.302 X  + 1 and R2 = 0.98) were obtained by using the Stern-Volmer relationship. The Limit of detection (LOD) was determined 0.000823 µM. The achieved results well confirm the outcomes of the RT-PCR method in real samples.


Assuntos
COVID-19 , Compostos de Cádmio , Pontos Quânticos , DNA , Humanos , SARS-CoV-2 , Sulfetos , Telúrio , Compostos de Zinco
3.
J Environ Sci (China) ; 113: 72-80, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34963551

RESUMO

As a typical class of emerging organic contaminants (EOCs), the environmental transformation and abatement of preservative parabens have raised certain environmental concerns. However, the remediation of parabens-contaminated water using natural matrixes (such as, naturally abundant minerals) is not reported extensively in literature. In this study, the transformation kinetics and the mechanism of ethylparaben using natural sphalerite (NS) were investigated. The results show that around 63% of ethylparaben could be absorbed onto NS within 38 hr, whereas the maximum adsorption capacity was 0.45 mg/g under room temperature. High temperature could improve the adsorption performance of ethylparaben using NS. In particular, for the temperature of 313 K, the adsorption turned spontaneous. The well-fitted adsorption kinetics indicated that both the surface adsorption and intra-particle diffusion contribute to the overall adsorption process. The monolayer adsorption on the surface of NS was primarily responsible for the elimination of ethylparaben. The adsorption mechanism showed that hydrophobic partitioning into organic matter could largely govern the adsorption process, rather than the ZnS that was the main component of NS. Furthermore, the ethylparaben adsorbed on the surface of NS was stable, as only less than 2% was desorbed and photochemically degraded under irradiation of simulated sunlight for 5 days. This study revealed that NS might serve as a potential natural remediation agent for some hydrophobic EOCs including parabens, and emphasized the significant role of naturally abundant minerals on the remediation of EOCs-contaminated water bodies.


Assuntos
Parabenos , Poluentes Químicos da Água , Adsorção , Cinética , Sulfetos , Água , Compostos de Zinco
4.
Environ Pollut ; 292(Pt B): 118414, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34728325

RESUMO

Incidental zinc sulfide nanoparticles (nano-ZnS) are spread on soils through organic waste (OW) recycling. Here we performed soil incubations with synthetic nano-ZnS (3 nm crystallite size), representative of the form found in OW. We used an original set of techniques to reveal the fate of nano-ZnS in two soils with different properties. 68Zn tracing and nano-DGT were combined during soil incubation to discriminate the available natural Zn from the soil, and the available Zn from the dissolved nano-68ZnS. This combination was crucial to highlight the dissolution of nano-68ZnS as of the third day of incubation. Based on the extended X-ray absorption fine structure, we revealed faster dissolution of nano-ZnS in clayey soil (82% within 1 month) than in sandy soil (2% within 1 month). However, the nano-DGT results showed limited availability of Zn released by nano-ZnS dissolution after 1 month in the clayey soil compared with the sandy soil. These results highlighted: (i) the key role of soil properties for nano-ZnS fate, and (ii) fast dissolution of nano-ZnS in clayey soil. Finally, the higher availability of Zn in the sandy soil despite the lower nano-ZnS dissolution rate is counterintuitive. This study demonstrated that, in addition to nanoparticle dissolution, it is also essential to take the availability of released ions into account when studying the fate of nanoparticles in soil.


Assuntos
Nanopartículas , Poluentes do Solo , Isótopos , Solo , Poluentes do Solo/análise , Sulfetos , Espectroscopia por Absorção de Raios X , Zinco/análise , Compostos de Zinco
5.
Chemosphere ; 286(Pt 1): 131672, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34346328

RESUMO

The glass system SiO2-B2O3-Na2O3-ZnO containing 2 wt% CdS and 1 wt% ZnS was synthesized by the conventional melt quench method. Glass transition temperature and crystallization temperature was determined from Differential thermal analysis (DTA) measurement to optimize heat-treatment. The amorphous structure of the glass was confirmed by the X-ray diffraction (XRD) measurement. Glasses were heat-treated by optimized heat-treatment schedule to grow CdS/ZnS QDs and crystalline phases of CdS and ZnS were confirmed by the XRD measurement. High-Resolution Transmission Electron Microscopy (HRTEM) was used to determine the size and shape of quantum dots (QDs) grown in the glass matrix. The optical band gap was calculated from the absorption spectra and found to decrease with increase in size of QDs. Electron-hole recombination rate was studied using a decay time and impedance analyzer. Prepared samples were tested as a photocatalyst under sunlight for the degradation of indigo carmine (IC) dye and photodegradation efficiency was found to be 73.6 % and 87.2 % for samples CZ1 and CZ4 respectively. No significant change is observed in degradation efficiency even for 4 cycles which confirms the stability of prepared glasses for dye degradation.


Assuntos
Pontos Quânticos , Carmim , Índigo Carmim , Dióxido de Silício , Sulfetos , Compostos de Zinco
6.
Food Chem ; 367: 130754, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384983

RESUMO

N-acetylneuraminic acid (Neu5Ac) is widely spread in many biologically significant glycans of mammals, commonly as a terminal α-glycoside. It is of great significance to develop analytical techniques for detection of Neu5Ac. Herein, a high-sensitive fluorescent biosensor for Neu5Ac has been developed based on FRET between CdSe/ZnS quantum dots (QDs) and BHQ2, as well as exonuclease III (Exo III)-assisted recycling amplification strategy. Employing the specially designed three-level FRET systems and fluorescent signal recovery mechanism, together with five-step recycling signal amplification chain reactions, an ultralow detection limit of 24 fM was achieved. Meanwhile, good linear response ranges within 0.2-12.5 pM and 12.5-1000 pM were founded. The assay has excellent performance in real sample detection, and thus offers great potential for detection of sialic acids modified glycans/lipids in the fields of medical diagnosis and food testing.


Assuntos
Compostos de Cádmio , Pontos Quânticos , Compostos de Selênio , Animais , DNA , Exodesoxirribonucleases , Transferência Ressonante de Energia de Fluorescência , Limite de Detecção , Ácidos Siálicos , Sulfetos , Compostos de Zinco
7.
Biosens Bioelectron ; 199: 113892, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34933225

RESUMO

Incorporating quantum dots (QDs) into dendritic mesoporous silica nanoparticles (DMSNs) for signal amplification of label materials represents an efficient strategy to improve the performance of lateral flow immunoassays (LFIAs). In this work, it is found that the CdSe/ZnS QD's size matters for balancing their loading amount and quantum yields (QYs) in the DMSNs-QDs based label materials and ultimately determining the performance of LFIA. The impacts of three CdSe/ZnS QDs with diameters of 9.1, 10.5 and 11.7 nm on CdSe/ZnS QDs incorporation and LFIA applications are studied. The increase of CdSe/ZnS QDs size from 9.1 to 11.7 nm results in a decrease in CdSe/ZnS QDs loading amount and an increase in QYs of incorporated CdSe/ZnS QDs. This trade-off leads to an optimized CdSe/ZnS QDs size of 10.5 nm, which exhibits the best LFIA performance due to the balanced QDs loading (2.26 g g-1) and QY (57.1%). The 10.5 nm CdSe/ZnS QDs incorporated DMSNs-QDs for C-reactive protein (CRP) detection achieved a limit of detection of 5 pg mL-1 (equivalent to 4.2 × 10-14 M) with naked eye, which is lower than literature reports and commercial LFIA products. This study demonstrates that the CdSe/ZnS QD's size matters for improving the quality of DMSNs-QDs and their LFIA performance for CRP determination, providing new insights into the rational design of advanced label materials for improving LFIA performance.


Assuntos
Técnicas Biossensoriais , Compostos de Cádmio , Pontos Quânticos , Compostos de Selênio , Proteína C-Reativa , Imunoensaio , Sulfetos , Compostos de Zinco
8.
Anal Chem ; 93(51): 17134-17140, 2021 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-34911298

RESUMO

The sensitive and accurate detection of microRNA (miRNA) has meaningful values for clinical diagnosis application as an early stage of tumor markers. Herein, a novel photoelectrochemical (PEC) biosensor was developed for the ultrasensitive and highly selective detection of microRNA-122 (miRNA-122) based on a direct Z-scheme heterojunction of Zn vacancy-mediated CdS/ZnS (CSZS-VZn). Impressively, the prepared Z-scheme heterojunction nanocomposite with defect level properties could make the photogenerated charges stay at the Zn vacancy defect levels and combine photogenerated holes in the valence bands of CdS, thus significantly achieving a better charge carrier separation efficiency and broadening the absorption of visible light and demonstrating 5-8 times enhancement of PEC response compared to single-component materials. Simultaneously, an exonuclease III (Exo-III)-assisted signal amplification strategy and a strand displacement reaction were combined to improve the conversion efficiency of the target and further increase the detection sensitivity. More importantly, the elaborated biosensor showed ultrasensitive and highly specific detection of the target miRNA-122 over a wide linear range from 10 aM to 100 pM with a low detection limit of 3.3 aM and exhibited enormous potential in the fields of bioanalysis and clinical diagnosis.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Técnicas Eletroquímicas , Limite de Detecção , MicroRNAs/genética , Sulfetos , Zinco , Compostos de Zinco
9.
Anticancer Res ; 41(11): 5453-5459, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34732414

RESUMO

BACKGROUND: Zinc is a mineral that is essential for biological molecules, such as transcription factors, and is involved in the maintenance of intestinal homeostasis. Vitamin D signaling is mediated by vitamin D receptor (VDR) activated by 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] and is also important in intestinal functions, such as calcium absorption and epithelial barrier maintenance. However, the crosstalk between vitamin D signaling and zinc signaling in intestinal cells remains poorly understood. MATERIALS AND METHODS: Colon cancer SW480 and HCT116 cells were treated with zinc chloride (ZnCl2) with/without 1,25(OH)2D3 Expression of zinc-inducible genes [metallothionein 1A (MT1A) and MT2A] and VDR target genes [cytochrome P450 family 24 subfamily A member 1 (CYP24A1), transient receptor potential cation channel subfamily V member 6 (TRPV6) and cadherin 1 (CDH1)] was examined. RESULTS: Treatment of cells with ZnCl2 effectively induced MT1A and MT2A mRNA expression, and interestingly suppressed mRNA expression of CDH1, which was induced by 1,25(OH)2D3 in both cell lines. ZnCl2 also reduced the CDH1 protein level in HCT116 cells. CONCLUSION: Zinc signaling suppresses VDR-induced expression of CDH1.


Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Calcitriol/farmacologia , Cloretos/farmacologia , Neoplasias do Colo/metabolismo , Receptores de Calcitriol/agonistas , Compostos de Zinco/farmacologia , Antígenos CD/genética , Caderinas/genética , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Humanos , Metalotioneína/genética , Metalotioneína/metabolismo , Receptores de Calcitriol/metabolismo , Transdução de Sinais
10.
Int J Mol Sci ; 22(19)2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34638673

RESUMO

Steroid-associated osteonecrosis (SAON) is a chronic disease that leads to the destruction and collapse of bone near the joint that is subjected to weight bearing, ultimately resulting in a loss of hip and knee function. Zn2+ ions, as an essential trace element, have functional roles in improving the immunophysiological cellular environment, accelerating bone regeneration, and inhibiting biofilm formation. In this study, we reconstruct SAON lesions with a three-dimensional (3D)-a printed composite made of poly (epsilon-caprolactone) (PCL) and nanoparticulate Willemite (npW). Rabbit bone marrow stem cells were used to evaluate the cytocompatibility and osteogenic differentiation capability of the PCL/npW composite scaffolds. The 2-month bone regeneration was assessed by a Micro-computed tomography (micro-CT) scan and the expression of bone regeneration proteins by Western blot. Compared with the neat PCL group, PCL/npW scaffolds exhibited significantly increased cytocompatibility and osteogenic activity. This finding reveals a new concept for the design of a 3D-printed PCL/npW composite-based bone substitute for the early treatment of osteonecrosis defects.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Fêmur/efeitos dos fármacos , Nanopartículas/administração & dosagem , Osteogênese/efeitos dos fármacos , Poliésteres/farmacologia , Tecidos Suporte/química , Animais , Caproatos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Lactonas/farmacologia , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteonecrose/tratamento farmacológico , Impressão Tridimensional , Coelhos , Silicatos/farmacologia , Engenharia Tecidual/métodos , Microtomografia por Raio-X/métodos , Compostos de Zinco/farmacologia
11.
Int J Mol Sci ; 22(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34638795

RESUMO

Liposome size and in vitro release of the active substance belong to critical quality attributes of liposomal carriers. Here, we apply asymmetric flow field-flow fractionation (AF4) to characterize theranostic liposomes prepared by thin lipid film hydration/extrusion or microfluidics. The vesicles' size was derived from multi-angle laser light scattering following fractionation (AF4) and compared to sizes derived from dynamic light scattering measurements. Additionally, we adapted a previously developed AF4 method to study zinc phthalocyanine (ZnPc) release/transfer from theranostic liposomes. To this end, theranostic liposomes were incubated with large acceptor liposomes serving as a sink (mimicking biological sinks) and were subsequently separated by AF4. During incubation, ZnPc was transferred from donor to acceptor fraction until reaching equilibrium. The process followed first-order kinetics with half-lives between 119.5-277.3 min, depending on the formulation. The release mechanism was postulated to represent a combination of Fickian diffusion and liposome relaxation. The rate constant of the transfer was proportional to the liposome size and inversely proportional to the ZnPc/POPC molar ratio. Our results confirm the usefulness of AF4 based method to study in vitro release/transfer of lipophilic payload, which may be useful to estimate the unwanted loss of drug from the liposomal carrier in vivo.


Assuntos
Liberação Controlada de Fármacos , Isoindóis/farmacocinética , Lipossomos , Microfluídica , Compostos Organometálicos/farmacocinética , Compostos de Zinco/farmacocinética , Fracionamento por Campo e Fluxo , Cinética , Tamanho da Partícula , Medicina de Precisão
12.
Colloids Surf B Biointerfaces ; 208: 112140, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34597939

RESUMO

Semiconductor quantum dots (QDs) have been extensively explored for extensive bioapplications, yet their cellular fate, especially exocytosis, has not been thoroughly investigated. Herein, we systematically investigated the whole cellular process from the endocytosis, intercellular trafficking, to the exocytosis of a typical QD, core/shell CdSe/ZnS QD. Using confocal laser scanning microscopy and flow cytometry, and after carefully eliminating the effect of cell division, we found that the QDs were internalized by HeLa cells with a time-, dose-, and serum-dependent manner. The cellular uptake was inhibited by serum, but eventually peaked after 4-6 h incubation with or without serum. The primary endocytosis pathway was clathrin-mediated, and actin- and microtubule-dependent in the medium with serum, while the caveolae-mediated endocytosis and macropinocytosis were more important for the QDs in the serum-free medium. Inside cells, most QDs distributed in lysosomes, and some entered mitochondria, endoplasmic reticulum, and Golgi apparatus. The translocation of the QDs from other organelles to Golgi apparatus was observed. The exocytosis of QDs was faster than the endocytosis, reaching the maximum in about one hour after cultured in fresh culture medium, with around 60% of the internalized QDs remained undischarged. The exocytosis process was energy- and actin-dependent, and the lysosome exocytosis and endoplasmic reticulum/Golgi pathway were the main routes. This study provides a full picture of behavior and fate of QDs in cells, which may facilitate the design of ideal QDs applied in biomedical and other fields.


Assuntos
Compostos de Cádmio , Pontos Quânticos , Compostos de Selênio , Endocitose , Exocitose , Células HeLa , Humanos , Sulfetos , Compostos de Zinco
13.
IET Nanobiotechnol ; 15(8): 664-673, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34694721

RESUMO

Zinc sulphide (ZnS) nanoparticles were synthesized by the coprecipitation method. The ZnS nanoparticle surface was polymerized with allyl glycidyl ether (AGE), and 3-aminophenol was then deposited as a ligand on nanosorbent. The modified nanosorbent was investigated with Fourier transform infrared spectroscopy and thermogravimetric analysis. The particle size of the modified nanosorbent was studied with scanning electron microscopy. Some characteristic factors of the adsorption process such as pH and time were investigated for famotidine using the modified nanosorbent. The equilibrium adsorption study of famotidine by 3-aminophenol-grafted AGE/ZnS was analysed by adsorption isotherms of the Langmuir, Freundlich, and Temkin models. The famotidine-releasing process was investigated in simulated biological fluids (intestinal fluid at pH of 7.4 and gastric fluid at pH of 1.2) and demonstrated 65% and 73% famotidine release during periods of 30 h (pH = 7.4) and 60 min (pH = 1.2), respectively. These results reveal the optimal performance of 3-aminophenol-grafted AGE/ZnS for sustained drug delivery.


Assuntos
Nanopartículas de Magnetita , Nanopartículas , Adsorção , Aminofenóis , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Cinética , Polímeros , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfetos , Compostos de Zinco
14.
Biomacromolecules ; 22(10): 4284-4294, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34569232

RESUMO

Highly tumor-tissue-selective drugs are a prerequisite for accurate diagnosis and efficient photodynamic therapy (PDT) of tumors, but the currently used fluorescent dyes and photosensitizers generally lack the ability for high accumulation and precise localization in tumor tissues. Here we report that monomethoxy polyethylene glycol (MPEG)-modified zinc phthalocyanine (ZnPc) can be selectively accumulated in multiple tumor tissues, and that the selectivity is controlled by the chain length of MPEG. MPEG-monosubstituted ZnPcs with different chain lengths were synthesized, among which the shorter chain (mw < 2k)-modified ZnPc did not show tumor tissue selectivity, while MPEG2k-5k-substituted ZnPc could be rapidly and selectively accumulated in H22 tumor tissues in mice after intravenous injection. Especially, MPEG4k-Pc showed the best tumor tissue selectivity with a tumor/liver (T/L) ratio of 1.7-2.2 in HepG2, MDA-MB231, AGS, and HT-29 tumor-bearing mice. It also exhibited potent photodynamic therapy effects after one PDT treatment, and tumor growth was significantly inhibited in H22-bearing mice with an inhibition rate over 98% and no obvious toxicity. Consequently, MPEG-modified ZnPc could serve as a potential platform for selective fluorescence imaging and photodynamic therapy of multiple tumors.


Assuntos
Compostos Organometálicos , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Isoindóis , Camundongos , Imagem Óptica , Compostos Organometálicos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis , Compostos de Zinco
15.
Water Sci Technol ; 84(5): 1170-1181, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534114

RESUMO

Food waste has been a complex component added to municipal solid waste, making it a major reason for the evolution of greenhouse gases, foul odour and a dwelling habitat for insects and microbes. Diversion of the mixed food waste (unsegregated) to useful materials (activated carbon) would have immense industrial significance. In this study, rice, vegetables, oil and spice (WCVR); mixed fruit peels including banana peel, pomegranate peel, orange peel and lemon peel (MFPW); plain rice (WCR) and mixed food waste (rice, dhal, vegetables, fruits, meat and bones) (MFW) were used. Food waste samples were heated at a temperature of 350 °C for 3 h in an incinerator and then activated with zinc chloride for 2 h in a muffle furnace maintained at 500-600 °C temperature. Zinc chloride activated carbon was characterized through X-ray diffraction, field emission scanning electron microscopy and fourier transform infrared spectroscopy. WCR carbon was the best-activated carbon, yielding nanomaterials with 2θ = 25.81, 31.76, 34.41 and 56.54, which was in accordance with the JCPDS card number. The MFW activated carbon reduced the biodiesel wash water pH from 10 to 6.5 making it suitable for recycling. Turbidity was reduced by 98.41%, chemical oxygen demand by 41.33%, oil and grease by 99.05% for MFW carbon.


Assuntos
Poluentes Ambientais , Eliminação de Resíduos , Adsorção , Biocombustíveis , Carvão Vegetal , Cloretos , Frutas , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias , Água , Compostos de Zinco
16.
ACS Infect Dis ; 7(10): 2917-2929, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34570483

RESUMO

Multifunctional antimicrobial peptides that combine the intrinsic microbicidal property of cationic polypeptide chains and additional antibacterial strategy hold promising applications for the treatment of infections caused by antibiotic-resistant bacteria, especially "superbugs". In the present study, star-shaped copolymers ZnPc-g-PLO with a zinc phthalocyanine (ZnPc) core and four poly(l-ornithine) (PLO) arms were designed, synthesized, and evaluated as dual-functional antimicrobial agents, that is, intrinsic membrane damage and photothermal ablation capacity. In an aqueous solution, amphiphilic ZnPc-g-PLO molecules self-assemble into nanosized polymeric micelles with an aggregated ZnPc core and star-shaped PLO periphery, where the ZnPc core exhibits appreciable aggregation-induced photothermal conversion efficiency. In the absence of laser irradiation, ZnPc-g-PLO micelles display potent and broad-spectrum antibacterial activities via physical bacterial membrane disruption as a result of the high cationic charge density of the star-shaped PLO. Upon laser irradiation, significant improvement in bactericidal potency was realized due to the efficacious photothermal sterilization from the ZnPc core. Notably, ZnPc-g-PLO micelles did not induce drug-resistance upon subinhibitory passages. In summary, dual-functional ZnPc-g-PLO copolymers can serve as promising antibacterial agents for the treatment of infectious diseases caused by antibiotic-resistant bacteria.


Assuntos
Anti-Infecciosos , Compostos Organometálicos , Indóis , Isoindóis , Ornitina , Compostos de Zinco
17.
Viruses ; 13(8)2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34452480

RESUMO

We compared the electrostatic properties of the spike proteins (S-proteins) of three coronaviruses, SARS-CoV, MERS-CoV, and SARS-CoV-2, and their interactions with photosensitizers (PSs), octacationic octakis(cholinyl)zinc phthalocyanine (Zn-PcChol8+) and monocationic methylene blue (MB). We found a major common PS binding site at the connection of the S-protein stalk and head. The molecules of Zn-PcChol8+ and MB also form electrostatic encounter complexes with large area of negative electrostatic potential at the head of the S-protein of SARS-CoV-2, between fusion protein and heptad repeat 1 domain. The top of the SARS-CoV spike head demonstrates a notable area of electrostatic contacts with Zn-PcChol8+ and MB that corresponds to the N-terminal domain. The S-protein protomers of SARS-CoV-2 in "open" and "closed" conformations demonstrate different ability to attract PS molecules. In contrast with Zn-PcChol8+, MB possesses the ability to penetrate inside the pocket formed as a result of SARS-CoV-2 receptor binding domain transition into the "open" state. The existence of binding site for cationic PSs common to the S-proteins of SARS-CoV, SARS-CoV-2, and MERS-CoV creates prospects for the wide use of this type of PSs to combat the spread of coronaviruses.


Assuntos
Indóis/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Compostos Organometálicos/metabolismo , Fármacos Fotossensibilizantes/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Sítios de Ligação , Indóis/química , Isoindóis , Azul de Metileno/metabolismo , Modelos Moleculares , Simulação de Dinâmica Molecular , Compostos Organometálicos/química , Conformação Proteica , Domínios Proteicos , Subunidades Proteicas/química , Vírus da SARS/química , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/química , Eletricidade Estática , Compostos de Zinco
18.
Anal Chem ; 93(36): 12250-12256, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34463494

RESUMO

Electrochemiluminescence (ECL) of low triggering potential is strongly anticipated for ECL assays with less inherent electrochemical interference and improved long-term stability of the working electrode. Herein, effects of the thiol capping agents and the states of luminophores, i.e., the thiol-capped CuInS2@ZnS nanocrystals (CuInS2@ZnS-Thiol), on the ECL triggering potential of CuInS2@ZnS-Thiol/N2H4·H2O were explored on the Au working electrode. The thiol capping agent of glutathione (GSH) not only enabled CuInS2@ZnS-Thiol/N2H4·H2O with the stronger oxidative-reduction ECL than other thiol capping agents but also demonstrated the largest shift for the ECL triggering potential of CuInS2@ZnS-Thiol/N2H4·H2O upon changing the luminophores from the monodispersed state to the surface-confined state. CuInS2@ZnS-GSH/N2H4·H2O exhibited an efficient oxidative-reduction ECL around 0.78 V (vs Ag/AgCl) with CuInS2@ZnS-GSH of the monodispersed state. Upon employing CuInS2@ZnS-GSH as the ECL tag and immobilizing them onto the Au working electrode, the oxidative-reduction ECL of CuInS2@ZnS-GSH/N2H4·H2O was lowered to 0.32 V (vs Ag/AgCl), which was about 0.88 V lower than that of traditional Ru(bpy)32+/TPrA (typically ∼1.2 V, vs Ag/AgCl). The ECL of the CuInS2@ZnS-GSH/N2H4·H2O system with the luminophore of both monodispersed and surface-confined states was spectrally identical to each other, indicating that this surface-confining strategy exhibited negligible effect on the excited state for the ECL of CuInS2@ZnS-GSH. A surface-confined ECL sensor around 0.32 V was fabricated with CuInS2@ZnS-GSH as a luminophore, which could sensitively and selectively determine the K-RAS gene from 1 to 500 pM with a limit of detection at 0.5 pmol L-1 (S/N = 3).


Assuntos
Medições Luminescentes , Nanopartículas , Sulfetos , Compostos de Zinco
19.
Mycoses ; 64(10): 1291-1297, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34420245

RESUMO

BACKGROUND: The enormous increase in COVID-19-associated mucormycosis (CAM) in India lacks an explanation. Zinc supplementation during COVID-19 management is speculated as a contributor to mucormycosis. We conducted an experimental and clinical study to explore the association of zinc and mucormycosis. METHODS: We inoculated pure isolates of Rhizopus arrhizus obtained from subjects with CAM on dichloran rose Bengal chloramphenicol (DRBC) agar enriched with (three different concentrations) and without zinc. At 24 h, we counted the viable colonies and measured the dry weight of colonies at 24, 48 and 72 h. We also compared the clinical features and serum zinc levels in 29 CAM cases and 28 COVID-19 subjects without mucormycosis (controls). RESULTS: We tested eight isolates of R arrhizus and noted a visible increase in growth in zinc-enriched media. A viable count percentage showed a significantly increased growth in four of the eight isolates in zinc-augmented DRBC agar. A time- and concentration-dependent increase in the mean fungal biomass with zinc was observed in all three isolates tested. We enrolled 29 cases of CAM and 28 controls. The mean serum zinc concentration was below the reference range in all the subjects and was not significantly different between the cases and controls. CONCLUSIONS: Half of the R arrhizus isolates grew better with zinc enrichment in vitro. However, our study does not conclusively support the hypothesis that zinc supplementation contributed to the pathogenesis of mucormycosis. More data, both in vitro and in vivo, may resolve the role of zinc in the pathogenesis of CAM.


Assuntos
COVID-19/epidemiologia , Mucormicose/epidemiologia , Rhizopus oryzae/crescimento & desenvolvimento , Compostos de Zinco/efeitos adversos , Compostos de Zinco/metabolismo , COVID-19/patologia , Estudos de Casos e Controles , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Mucormicose/mortalidade , Mucormicose/patologia , Rhizopus oryzae/isolamento & purificação , SARS-CoV-2/isolamento & purificação , Compostos de Zinco/uso terapêutico
20.
Angew Chem Int Ed Engl ; 60(42): 22977-22982, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34427992

RESUMO

We report a Ni-catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3-triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate-limiting single-electron-transfer process and is autocatalyzed by in-situ-generated ZnX2 . The reaction rate is amplified by a factor of three through autocatalysis upon addition of ZnX2 .


Assuntos
Alcenos/química , Brometos/química , Níquel/química , Compostos de Zinco/química , Compostos de Benzil/química , Catálise , Cinética
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