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A selective and sensitive fluorometric assay was developed for specific determination of curcumin (Cur) based on fluorescence resonance energy transfer (FRET) between molybdenum disulfide quantum dots (MoS2 QDs) and Cur. The MoS2 QDs were prepared via a one-step hydrothermal protocol using sodium molybdate dihydrate, L-cysteine (Cys) as precursors, and sodium cholate (SC) as a modification agent. The as-prepared MoS2 QDs possessed maximum fluorescence emission at 460 nm with a 20% of fluorescence quantum yield (FQY). It was found that the fluorescence of MoS2 QDs could be quantitatively quenched by Cur through FRET mechanism. Therefore, Cur could be detected in the range of 0.1-20 µg mL- 1 with a detection limit of 5 ng mL- 1. Additionally, the developed MoS2 QDs based fluorescent assay has been successfully applied for real food sample analysis with satisfactory results.
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BACKGROUND: Acute lung injury (ALI) is a fatal respiratory disease caused by overreactive immune reactions (e.g., SARS-CoV-2 infection), with a high mortality rate. Its treatment is often compromised by inefficient drug delivery barriers and insufficient potency of the currently used drugs. Therefore, developing a highly effective lung-targeted drug delivery strategy is a pressing clinical need. RESULTS: In this study, the micro-sized inclusion cocrystal of asiatic acid/γ-cyclodextrin (AA/γCD, with a stoichiometry molar ratio of 2:3 and a mean size of 1.8 µm) was prepared for ALI treatment. The dissolution behavior of the AA/γCD inclusion cocrystals followed a "spring-and-hover" model, which meaned that AA/γCD could dissolve from the cocrystal in an inclusion complex form, thereby promoting a significantly improved water solubility (nine times higher than free AA). This made the cyclodextrin-based inclusion cocrystals an effective solid form for enhanced drug absorption and delivery efficiency. The biodistribution experiments demonstrated AA/γCD accumulated predominantly in the lung (Cmax = 50 µg/g) after systemic administration due to the micron size-mediated passive targeting effect. The AA/γCD group showed an enhanced anti-inflammatory therapeutic effect, as evidenced by reduced levels of pro-inflammatory cytokines in the lung and bronchoalveolar lavage fluids (BALF). Histological examination confirmed that AA/γCD effectively inhibited inflammation reactions. CONCLUSION: The micro-sized inclusion cocrystals AA/γCD were successfully delivered into the lungs by pulmonary administration and had a significant therapeutic effect on ALI.
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Lesão Pulmonar Aguda , Ciclodextrinas , Triterpenos Pentacíclicos , Humanos , Ciclodextrinas/química , Distribuição Tecidual , Sistemas de Liberação de Medicamentos , Lesão Pulmonar Aguda/tratamento farmacológico , SolubilidadeRESUMO
Chiral nanoparticles (C-NPs) play a crucial role in biomedical applications, especially in their biological effects on cytotoxicity and metabolism. However, there are rare reports about the antivirus property of C-NPs and their working mechanism. Here, three different types of chiral ZnO NPs (l-ZnO, d-ZnO, and dl-ZnO) were prepared as enantioselective antivirals. Biocompatibility test results showed that the three different chiral ZnO NPs varied significantly in cytotoxicity. Evaluation of their effects against porcine reproductive and respiratory syndrome virus (PRRSV) indicated that compared with d-ZnO and dl-ZnO NPs, l-ZnO NPs exhibited stronger anti-PRRSV activity due to their higher cognate cell adhesion and uptake. Furthermore, the high concentration of l-ZnO NPs can obviously reduce cellular reactive oxygen species (ROS) in MARC-145 cells, thus effectively preventing PRRSV-induced oxidative damage. This study demonstrated the outstanding antiviral properties of l-ZnO NPs, which may facilitate the development and application of C-NPs in antiviral drugs and tissue engineering.
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Nanopartículas Metálicas , Nanopartículas , Óxido de Zinco , Óxido de Zinco/farmacologia , Estereoisomerismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Antivirais/farmacologiaRESUMO
Traditional Chinese medicines (TCMs)/nanopreparations as viral antagonists exhibited a structure-function correlation, i.e., the differences in surface area/volume ratio caused by the variations in shape and size could result in different biochemical properties and biological activities, suggesting an important impact of morphology and structure on the antiviral activity of TCM-based nanoparticles. However, few studies paid attention to this aspect. Here, the effect of TCM-based nanoparticles with different morphologies on their antiviral activity was explored by synthesizing rhein/silver nanocomposites (Rhe@AgNPs) with spherical (S-Rhe/Ag) and linear (L-Rhe/Ag) morphologies, using rhein (an active TCM ingredient) as a reducing agent and taking its self-assembly advantage. Using porcine reproductive and respiratory syndrome virus (PRRSV) as a model virus, the inhibitory effects of S-Rhe/Ag and L-Rhe/Ag on PRRSV were compared. Results showed that the product morphology could be regulated by varying pH values, and both S- and L-Rhe/Ag exhibited good dispersion and stability, but with a smaller size for L-Rhe/Ag. Antiviral experiments revealed that Rhe@AgNPs could effectively inhibit PRRSV infection, but the antiviral effect was morphology-dependent. Compared with L-Rhe/Ag, S-Rhe/Ag could more effectively inactivate PRRSV in vitro and antagonize its adsorption, invasion, replication, and release stages. Mechanistic studies indicated that Rhe@AgNPs could reduce the production of reactive oxygen species (ROS) induced by PRRSV infection, and S-Rhe/Ag also had stronger ROS inhibitory effect. This work confirmed the inhibitory effect of Rhe@AgNPs with different morphologies on PRRSV and provided useful information for treating PRRSV infection with metal nanoparticles synthesized from TCM ingredients.
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N-acetyl-beta-D-glucosaminidase (NAG) is an important biomarker for early clinical diagnosis of renal disease, suggesting the necessity to develop a fast and sensitive method for its detection. In this paper, we developed a fluorescent sensor based on polyethylene glycol (400) (PEG-400)-modified and H2O2-assisted etched sulfur quantum dots (SQDs). According to the fluorescence inner filter effect (IFE), the fluorescence of SQDs can be quenched by the p-nitrophenol (PNP) generated by NAG-catalyzed hydrolysis of p-Nitrophenyl-N-acetyl-ß-D-glucosaminide (PNP-NAG). We successfully used the SQDs as a nano-fluorescent probe to detect the NAG activity from 0.4 to 7.5 U·L-1, with a detection limit of 0.1 U·L-1. Furthermore, the method is highly selective and was successfully used in the detection of NAG activity in bovine serum samples, suggesting its great application prospect in clinical detection.
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Pontos Quânticos , Acetilglucosaminidase , Peróxido de Hidrogênio , Corantes Fluorescentes , Hidrólise , Limite de DetecçãoRESUMO
In this work, we firstly found a strong competitive interaction between thiram and silver atoms of DNA-templated silver nanoclusters (DNA-AgNCs), leading to fluorescence quenching of DNA-AgNCs without additional metal ion-mediator. Furthermore, this thiram-induced fluorescence quenching phenomenon was used to develop a sensor for thiram detection. This fluorescence sensor exhibited good linearity with thiram concentration from 0.20 to 2.0 µM and 0.012-0.20 µM under optimized conditions, with a low detection limit of 0.2 µM and 0.01 µM, respectively. Moreover, this sensor showed superior selectivity towards thiram, and its practicability was verified in apples and soil. This study provides a convenient and rapid "mix and detect" approach for thiram detection within 10 min, suggesting its potential for rapid on-site evaluation of thiram in real samples.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Prata , Tiram , Fluorescência , DNA , Espectrometria de Fluorescência , Limite de DetecçãoRESUMO
Alkaline phosphatase (ALP), one of the vital biomarkers in several diseases, plays a role in indicating disease presence or severity in early diagnosis. Here, a simple H2O2 assisted top-down method was used to synthesize sulfur quantum dots (SQDs) with excitation and emission at 355 nm and 440 nm. Adding ALP into p-nitrophenyl phosphate (p-NPP) and SQDs was found to exhibit a red shift in the emission wavelength and fluorescence intensity quenching of SQDs, respectively, allowing us to propose dual-sensor platforms of red shift of emission wavelength (RSEW) and fluorescence quenching of SQDs. These dual-sensor platforms were highly sensitive and selective in ALP detection, with a linear response to ALP in the concentration range of 0.25 to 100 U L-1 and detection limits of 0.08 and 0.10 U L-1, respectively. The absorption of p-NP at 400 nm showed a good overlap with the excitation and emission of SQDs, leading to inner filter effect-based RSEW and fluorescence quenching of SQDs. This sensor platform was successfully applied in ALP sensing of serum samples as well as monitoring of ALP in cells. More importantly, this platform can serve as an example of using RSEW to detect ALP.
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Pontos Quânticos , Fosfatase Alcalina , Peróxido de Hidrogênio , Limite de Detecção , Corantes FluorescentesRESUMO
Due to their unique optical property, low toxicity, high hydrophilicity, and low cost, sulfur quantum dots (SQDs), an emerging luminescent nanomaterial, have shown great potential in various application fields, such as sensing, bioimaging, light emitting diode, catalysis, and anti-bacteria. This minireview updates the synthetic methods and sensing/bioimaging applications of SQDs in the last few years, followed by discussion of the potential challenges and prospects in their synthesis and sensing/bioimaging applications, with the purpose to provide some useful information for researchers in this field.
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Nanoestruturas , Pontos Quânticos , Catálise , Luminescência , EnxofreRESUMO
A 'turn-on' fluorescence method for detection of hydrogen peroxide (H2 O2 ) in marine food samples is presented in this article. Using this method, a carbon dots (CDs)-MnO2 probe was formed in which fluorescence intensity (FI) of CDs was quenched through fluorescence resonance energy transfer by addition of MnO2 nanosheets. When H2 O2 was added into the CDs-MnO2 solution, the MnO2 nanosheets formed Mn2+ ions due to a redox reaction between H2 O2 and MnO2 nanosheets, and CD FI was recovered. Under optimized conditions, the detection limit for H2 O2 was 0.87 µM, and analytical linear range was 4-100 µM. Furthermore, this developed fluorescence sensing system was successfully used with satisfactory results to determine trace H2 O2 content in marine food samples.
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Compostos de Manganês , Pontos Quânticos , Carbono , Peróxido de Hidrogênio , ÓxidosRESUMO
In the present work, a selective and sensitive method for detecting TNP using manganese doped carbon quantum dots (Mn-CDs) was developed. The Mn-CDs were prepared via a simple hydrothermal method using 1-(2-pyridinylazo)-2-naohthalenol naohthalenol (PAN) and MnCl2 as precursors. The as-prepared Mn-CDs have UV emission with high quantum yield (83.2%). Because of the strong characteristic absorption of TNP at 356â¯nm, which has good spectral overlap with the emission peak of Mn-CDs, the fluorescence intensity of Mn-CDs at 360â¯nm is linearly quenched in the presence of TNP in the concentration range of 0.1-200⯵M. The developing assay based on an inner filter effect (IFE) mechanism for detecting TNP is selective, convenient, and shows that the as-prepared Mn-CDs have application prospects for simple and specific analytical chemistry.