RESUMO
The contamination of mycotoxins poses a serious threat to global food security, hence the urgent need for simultaneous detection of multiple mycotoxins. Herein, two SERS nanoprobes were synthesized by embedded SERS tags (4-mercaptopyridine, 4MPy; 4-mercaptobenzonitrile, TBN) into the Au and Ag core-shell structure, and each was coupled with the aptamers specific to ochratoxin A (OTA) and zearalenone (ZEN). Meanwhile, a rigid enhanced substrate Indium tin oxide glass/AuNPs/Graphene oxide (ITO/AuNPs/GO) was combined with aptamer functionalized Au@AgNPs via π-π stacking interactions between the aptamer and GO to construct a surface-enhanced Raman spectroscopy (SERS) aptasensor, thereby inducing a SERS enhancement effect for the effective and swift simultaneous detection of both OTA and ZEN. The presence of OTA and ZEN caused signal probes dissociation, resulting in an inverse correlation between Raman signal intensity (1005 cm-1 and 2227 cm-1) and the concentrations of OTA and ZEN, respectively. The SERS aptasensor exhibited wide linear detection ranges of 0.001-20 ng/mL for OTA and 0.1-100 ng/mL for ZEN, with low detection limits (LOD) of 0.94 pg/mL for OTA and 59 pg/mL for ZEN. Furthermore, the developed SERS aptasensor demonstrated feasible applicability in the detection of OTA and ZEN in maize, showcasing its substantial potential for practical implementation.
Assuntos
Aptâmeros de Nucleotídeos , Ouro , Grafite , Limite de Detecção , Nanopartículas Metálicas , Ocratoxinas , Prata , Análise Espectral Raman , Zearalenona , Ocratoxinas/análise , Análise Espectral Raman/métodos , Ouro/química , Zearalenona/análise , Nanopartículas Metálicas/química , Aptâmeros de Nucleotídeos/química , Prata/química , Grafite/química , Compostos de Estanho/química , Técnicas Biossensoriais/métodos , Contaminação de Alimentos/análiseRESUMO
Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs. Subsequently, qualitative determination of migrating PAAs into various food simulants (4 % acetic acid, 10 % ethanol, 50 % ethanol) occurred at 70 °C for 2 h using liquid chromatography-mass spectrometry. Three PAAs including 4,4'-methylenedianiline, 2,4'-methylenedianiline, and 2,4-diaminotoluene were detected in all straws. Specifically, 2,4-diaminotoluene in 50 % ethanol exceeded specific migration limit of 2 µg/kg, raising safety concerns. Notably, PAAs migration to 10 % and 50 % ethanol surpassed that to 4 % acetic acid within a short 2-hour period. Moreover, PLA straws underwent varying degrees of shape changes before and after migration. Straws with poly(butylene succinate) resisted deformation compared to those without, indicating enhanced heat resistance, while poly(butyleneadipate-co-terephthalate) improved hydrolysis resistance. Importantly, swelling study unveiled swelling effect wasn't the primary factor contributing to the increased PAAs migration in ethanol food simulant, as there was no significant disparity in swelling degrees across different food simulants. FT-IR and DSC analysis revealed higher PAAs content in 50 % ethanol were due to highly concentrated polar ethanol disrupting hydrogen bonds and van der Waal forces holding PLA molecules together. Overall, minimizing contact between PLA straws and alcoholic foods is crucial to avoid potential safety risks posed by PAAs.
Assuntos
Aminas , Poliésteres , Análise Espectral Raman , Poliésteres/química , Análise Espectral Raman/métodos , Cromatografia Líquida/métodos , Aminas/análise , Aminas/química , Espectrometria de Massas/métodos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Espectrometria de Massa com Cromatografia LíquidaRESUMO
Raman Optical Activity combined with Circularly Polarized Luminescence (ROA-CPL) was used in the spectral recognition of glutathione peptide (GSH) and its model post-translational modifications (PTMs). We demonstrate the potential of ROA spectroscopy and CPL probes (EuCl3, Na3[Eu(DPA)3], NaEuEDTA) in the study of unmodified peptide, i.e. GSH, and its derivatives, i.e. glutathione oxidized (GSSG), S-acetylglutathione (GSAc) and S-nitrosoglutathione (GSNO). ROA spectral features of GSH, GSSG, and GSAc were determined along with thier changes upon the different pH conditions. Apart from the ROA, induced CPL signals of Eu(III) probes also proved to be sensitive to the structural modifications of GSH-based model PTMs, enabling their spectral recognition, especially by the NaEuEDTA probe.
Assuntos
Glutationa , Análise Espectral Raman , Glutationa/química , Luminescência , Medições Luminescentes , Processamento de Proteína Pós-Traducional , Concentração de Íons de HidrogênioRESUMO
Kidney stones are a common urological disease with an increasing incidence worldwide. Traditional diagnostic methods for kidney stones are relatively complex and time-consuming, thus necessitating the development of a quicker and simpler diagnostic approach. This study investigates the clinical screening of kidney stones using Surface-Enhanced Raman Scattering (SERS) technology combined with multivariate statistical algorithms, comparing the classification performance of three algorithms (PCA-LDA, PCA-LR, PCA-SVM). Urine samples from 32 kidney stone patients, 30 patients with other urinary stones, and 36 healthy individuals were analyzed. SERS spectra data were collected in the range of 450-1800 cm-1 and analyzed. The results showed that the PCA-SVM algorithm had the highest classification accuracy, with 92.9 % for distinguishing kidney stone patients from healthy individuals and 92 % for distinguishing kidney stone patients from those with other urinary stones. In comparison, the classification accuracy of PCA-LR and PCA-LDA was slightly lower. The findings indicate that SERS combined with PCA-SVM demonstrates excellent performance in the clinical screening of kidney stones and has potential for practical clinical application. Future research can further optimize SERS technology and algorithms to enhance their stability and accuracy, and expand the sample size to verify their applicability across different populations. Overall, this study provides a new method for the rapid diagnosis of kidney stones, which is expected to play an important role in clinical diagnostics.
Assuntos
Algoritmos , Cálculos Renais , Análise Espectral Raman , Humanos , Análise Espectral Raman/métodos , Cálculos Renais/urina , Cálculos Renais/diagnóstico , Análise Multivariada , Feminino , Masculino , Análise de Componente Principal , Pessoa de Meia-Idade , AdultoRESUMO
The acidity of atmospheric aerosols influences fundamental physicochemical processes that affect climate and human health. We recently developed a novel and facile water-probe-based method for directly measuring of the pH for micrometer-size droplets, providing a promising technique to better understand aerosol acidity in the atmosphere. The complex chemical composition of fine particles in the ambient air, however, poses certain challenges to using a water-probe for pH measurement, including interference from interactions between compositions and the influence of similar compositions on water structure. To explore the universality of our method, it was employed to measure the pH of ammonium, nitrate, carbonate, sulfate, and chloride particles. The pH of particles covering a broad range (0-14) were accurately determined, thereby demonstrating that our method can be generally applied, even to alkaline particles. Furthermore, a standard spectral library was developed by integrating the standard spectra of common hydrated ions extracted through the water-probe. The library can be employed to identify particle composition and overcome the spectral overlap problem resulting from similar effects. Using the spectral library, all ions were identified and their concentrations were determined, in turn allowing successful pH measurement of multicomponent (ammonium-sulfate-nitrate-chloride) particles. Insights into the synergistic effect of Cl-, NO3-, and NH4+ depletion obtained with our approach revealed the interplay between pH and volatile partitioning. Given the ubiquity of component partitioning and pH variation in particles, the water probe may provide a new perspective on the underlying mechanisms of aerosol aging and aerosol-cloud interaction.
Assuntos
Aerossóis , Monitoramento Ambiental , Análise Espectral Raman , Água , Concentração de Íons de Hidrogênio , Análise Espectral Raman/métodos , Água/química , Monitoramento Ambiental/métodos , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Atmosfera/química , Material Particulado/análiseRESUMO
Retinol is widely used to treat skin ageing because of its effect on cell differentiation, proliferation and apoptosis. However, its potential benefits appear to be limited by its skin permeability. Herein, we investigated the transcutaneous behavior of retinol in semisolid cosmetics, in both in vitro and in vivo experiments. In vitro experiments used the modified Franz diffusion cell combined with Raman spectroscopy. In in vivo experiments, the content of retinol in rat skin and plasma was detected with HPLC. Retinol in semisolid cosmetics was mainly concentrated in the stratum corneum in the skin of the three animal models tested, and in any case did not cross the skin barrier after a 24 h dermatologic topical treatment in Franz diffusion cells tests. Similar results were obtained in live mice and rats, where retinol did not cross the skin barrier and did not enter the blood circulation. Raman spectroscopy was used to test the penetration depth of retinol in skin, which reached 16 µm out of 34 µm in pig skin, whereas the skin of mouse and rat showed too strong bakground interference. To explore epidermal transport mechanism and intradermal residence, skin transcriptomics was performed in rats, which identified 126 genes upregulated related to retinol transport and metabolism, relevant to the search terms "retinoid metabolic process" and "transporter activity". The identity of these upregulated genes suggests that the mechanism of retinol action is linked to epidermis, skin, tissue and epithelium development.
Assuntos
Cosméticos , Absorção Cutânea , Pele , Vitamina A , Animais , Vitamina A/metabolismo , Vitamina A/farmacocinética , Camundongos , Ratos , Pele/metabolismo , Administração Cutânea , Análise Espectral Raman , Suínos , Masculino , Permeabilidade , Epiderme/metabolismoRESUMO
Rapid and reliable detection method for African swine fever virus (ASFV) is proposed by surface-enhanced Raman spectroscopy (SERS). The ASFV target DNA can be specifically captured by sandwich hybridization between nanomagnetic beads and a SERS probe. Experimental results show that the significant Raman signal of the SERS probe with gold nanoparticles and a molecular reporter DTNB (5,5'-dimercapto-bis (2-nitrobenzoic acid)) can be adopted for detecting the hybridization chain reaction of ASFV DNA. The advantage of the SERS sandwich hybridization assay is the large response range from the single molecule level to 108 copies per mL, which not only can overcome the tedious time required for the amplification reaction but also provides a comparative method to polymerase chain reaction. Furthermore, real samples of African swine fever virus were detected from different subjects of swine fever virus including porcine reproductive respiratory syndrome virus and Japanese encephalitis virus. The proposed biosensor method can rapidly detect ASFV correctly within 15 min as a simple, convenient, low-cost detection approach. The biosensor can be used as a platform for the determination in biological, food, and environmental analytical fields.
Assuntos
Vírus da Febre Suína Africana , Ouro , Nanopartículas Metálicas , Hibridização de Ácido Nucleico , Análise Espectral Raman , Vírus da Febre Suína Africana/isolamento & purificação , Vírus da Febre Suína Africana/genética , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Animais , Ouro/química , Técnicas Biossensoriais/métodos , Suínos , DNA Viral/análise , DNA Viral/genética , Limite de Detecção , Febre Suína Africana/diagnóstico , Febre Suína Africana/virologiaRESUMO
The ability to image tissues in three dimensions (3D) with label-free molecular contrast at the mesoscale would be a valuable capability in biology and biomedicine. Here, we introduce Raman spectral projection tomography (RSPT) for volumetric molecular imaging with optical sub-millimeter spatial resolution. We have developed a RSPT imaging instrument capable of providing 3D molecular contrast in transparent and semi-transparent samples. We also created a computational pipeline for multivariate reconstruction to extract label-free spatial molecular information from Raman projection data. Using these tools, we demonstrate imaging and visualization of phantoms of various complex shapes with label-free molecular contrast. Finally, we apply RSPT as a tool for imaging of molecular gradients and extracellular matrix heterogeneities in fixed and living tissue-engineered constructs and explanted native cartilage tissues. We show that there exists a favorable balance wherein employing Raman spectroscopy, with its advantages in live cell imaging and label-free molecular contrast, outweighs the reduction in imaging resolution and blurring caused by diffuse photon propagation. Thus, RSPT imaging opens new possibilities for label-free molecular monitoring of tissues.
Assuntos
Imageamento Tridimensional , Imagem Molecular , Imagens de Fantasmas , Análise Espectral Raman , Análise Espectral Raman/métodos , Imageamento Tridimensional/métodos , Animais , Imagem Molecular/métodos , Engenharia Tecidual/métodos , Humanos , Tomografia/métodos , Cartilagem/diagnóstico por imagem , Cartilagem/metabolismo , Matriz Extracelular/metabolismo , CamundongosRESUMO
BACKGROUND: Lignocellulosic biomass-based derivatives coupled with surface-enhanced Raman spectroscopy (SERS) technology have emerged as an appealing and indispensable tool in food safety and environmental monitoring for rapidly detecting trace contaminants like pesticide residues. The membrane material, serving as a substrate, ensures both sampling flexibility and test accuracy by directing the diffusion-adsorption process of the molecules. However, the existing membrane substrates, critical for the practical application of SERS, suffer from issues such as costly, intricate fabrication procedures, or restricted detection capabilities. RESULTS: Herein, we present a flexible, transparent, and biodegradable cellulose acetate membrane with gold nanoparticles (AuNPs) uniformly embedded, fabricated using a simple scraping method. This membrane achieved a limit of detection (LOD) of thiram pesticide in water at 10-8 g mL-1. The unique optical transparency of the substrates allowed for in-situ detection on surfaces, with an LOD of thiram reaching 30 ng cm-2. SIGNIFICANCE: Furthermore, SERS substrates made from corn stover-derived cellulose acetate enable the detection of various contaminants, highlighting their cost-effectiveness and eco-friendliness because of the abundance and low environmental impact of the raw materials.
Assuntos
Biomassa , Celulose , Ouro , Nanopartículas Metálicas , Análise Espectral Raman , Análise Espectral Raman/métodos , Ouro/química , Nanopartículas Metálicas/química , Celulose/química , Celulose/análogos & derivados , Tiram/análise , Membranas Artificiais , Estudos de Viabilidade , Limite de Detecção , Propriedades de Superfície , Poluentes Químicos da Água/análiseRESUMO
Heme released from damaged and senescent red blood cells (RBCs) may contribute to oxidant-mediated cell injury. One of the recently investigated physiological processes, essential in preventing the inflammatory impact of labile heme, is its uptake from the bloodstream by endothelial cells (ECs). In this study, we investigated heme uptake by ECs starting from the model studies on the in vitro cellular level, through the endothelium layer on the ex vivo murine aortic tissues. As the cellular model, Human Aortic Endothelial Cells (HAECs) were chosen, and the concentration of labile heme was adjusted so to avoid the excessive toxic effect of the labile heme. We utilized label-free Raman imaging with two different excitation wavelengths to capture the uptake process in situ and characterize the oxidation state of the iron ion in the intercalated heme. The phenomenon of heme uptake was demonstrated in both, the healthy control C57Bl/6J and FVB animals, as well as in mice with developed atherosclerosis (ApoE/LDLR-/- mice). In the presented work, we presented for the first time Raman-based evidence on the heme uptake process by endothelial cells in both, in vitro and ex vivo systems.
Assuntos
Células Endoteliais , Heme , Análise Espectral Raman , Animais , Heme/metabolismo , Análise Espectral Raman/métodos , Células Endoteliais/metabolismo , Camundongos , Humanos , Camundongos Endogâmicos C57BL , Aterosclerose/metabolismo , Aterosclerose/patologiaRESUMO
Although Surface Enhanced Raman Scattering (SERS) is widely applied for ultrasensitive diagnostics and imaging, its potential is largely limited by the difficult preparation of SERS tags, typically metallic nanoparticles (NPs) functionalized with Raman-active molecules (RRs), whose production often involves complex synthetic approaches, low colloidal stability and poor reproducibility. Here, we introduce LipoGold Tags, a simple platform where gold NPs (AuNPs) clusters form via self-assembly on lipid vesicle. RRs embedded in the lipid bilayer experience enhanced electromagnetic field, significantly increasing their Raman signals. We modulate RRs and lipid vesicle concentrations to achieve optimal SERS enhancement and we provide robust structural characterization. We further demonstrate the versatility of LipoGold Tags by functionalizing them with biomolecular probes, including antibodies. As proof of concept, we successfully detect intracellular GM1 alterations, distinguishing healthy donors from patients with infantile GM1 gangliosidosis, showcasing LipoGold Tags as advancement in SERS probes production.
Assuntos
Ouro , Nanopartículas Metálicas , Análise Espectral Raman , Ouro/química , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Humanos , Bicamadas Lipídicas/química , Lipídeos/química , Gangliosídeo G(M1)/químicaRESUMO
Surface-enhanced Raman spectroscopy (SERS) is a powerful method in analytical chemistry, but its application in real-life medical settings has been limited due to technical challenges. In this work, we introduce an innovative approach that is meant to advance the automation of microfluidics SERS to improve reproducibility and label-free quantification of two widely used therapeutic drugs, methotrexate (MTX) and lamotrigine (LTG), in human serum. Our methodology involves a miniaturized solid-phase extraction (µ-SPE) method coupled to a centrifugal microfluidics disc with incorporated SERS substrates (CD-SERS). The CD-SERS platform enables simultaneous controlled sample wetting and accurate SERS mapping. Together with the assay we implemented a machine learning method based on Partial Least Squares Regression (PLSR) for robust data analysis and drug quantification. The results indicate that combining µ-SPE with CD-SERS (µ-SPE to CD-SERS) led to a substantial improvement in the signal-to-noise ratio compared to combining CD-SERS with ultrafiltration or protein precipitation. The PLSR model enabled us to obtain the limit of detection and quantification for MTX as 2.90 and 8.92 µM, respectively, and for LTG as 10.76 and 32.29 µM. We also validated our µ-SPE to CD-SERS method for MTX against HPLC and immunoassay (p-value <0.05), using patient samples undergoing MTX therapy. In addition, we achieved a satisfactory recovery rate (80%) for LTG when quantifying it in patient samples. Our results show the potential of this newly developed approach as a strategy for therapeutic drugs in point-of-care clinical settings and highlight the benefits of automating label-free SERS assays.
Assuntos
Lamotrigina , Metotrexato , Extração em Fase Sólida , Análise Espectral Raman , Humanos , Extração em Fase Sólida/métodos , Lamotrigina/sangue , Análise Espectral Raman/métodos , Metotrexato/sangue , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Limite de Detecção , Microfluídica/métodos , Desenho de Equipamento , CentrifugaçãoRESUMO
PURPOSE: To evaluate the long-term microtensile bond strength (µTBS) to dentin, water sorption (WSP) and solubility (WSL), and degree of conversion (DC) of self-adhesive resin composites (SACs). MATERIALS AND METHODS: The mid-coronal dentin of human molars was exposed, and teeth were randomly assigned to five groups according to the SACs (n = 10): 1. FIT SA F03 (FIT); 2. Experimental (EXP); 3. Fusio Liquid Dentin (FLD); 4. Vertise Flow (VER); 5. Constic (CON). The µTBS was evaluated after 24 hours (24 h) and 6 months (6 m) storage. A scanning electron microscope examined failure modes and resin-dentin interfaces. The WSP and WSL (n = 5) were evaluated following ISO 4049:2019 specifications, and DC (n = 3) was measured using Raman spectroscopy. The statistical analyses were performed accepting a significance level of p = 0.05. RESULTS: FIT, EXP, and FLD produced significantly higher µTBS median values than VER and CON after 24 h and 6 m (p 0.05). After 6m, the µTBS median of FIT and EXP significantly decreased (p 0.05), while FLD, VER, and CON showed no significant difference (p > 0.05). FLD and CON exhibited lower WSP than FIT, EXP, and VER (p 0.05). FLD presented the lowest (p 0.05), and VER revealed the highest WSL (p 0.05). FIT and EXP showed the highest (p 0.05), and VER demonstrated the lowest DC (p 0.05). CONCLUSIONS: Following the present study's design, SACs' bonding performance and physical properties remained restricted. Therefore, the application should be considered cautiously, and further clinical trials are necessary to evaluate their long-term performance.
Assuntos
Resinas Compostas , Colagem Dentária , Dentina , Teste de Materiais , Solubilidade , Resistência à Tração , Água , Resinas Compostas/química , Humanos , Água/química , Microscopia Eletrônica de Varredura , Adesivos Dentinários/química , Cimentos de Resina/química , Análise Espectral Raman , Fatores de Tempo , Propriedades de Superfície , Análise do Estresse DentárioRESUMO
Sepsis following burn trauma is a global complication with high mortality, with â¼60% of burn patient deaths resulting from infectious complications. Diagnosing sepsis is complicated by confounding clinical manifestations of the burn injury, and current biomarkers lack the sensitivity and specificity required for prompt treatment. There is a strong rationale to assess circulating extracellular vesicles (EVs) from patient liquid biopsy as sepsis biomarkers due to their release by pathogens from bacterial biofilms and roles in the subsequent immune response. This study applies Raman spectroscopy to patient plasma-derived EVs for rapid, sensitive, and specific detection of sepsis in burn patients, achieving 97.5% sensitivity and 90.0% specificity. Furthermore, spectral differences between septic and non-septic burn patient EVs could be traced to specific glycoconjugates of bacterial strains associated with sepsis morbidity. This work illustrates the potential application of EVs as biomarkers in clinical burn trauma care and establishes Raman analysis as a fast, label-free method to specifically identify features of bacterial EVs relevant to infection amongst the host background.
Assuntos
Biomarcadores , Queimaduras , Vesículas Extracelulares , Sepse , Análise Espectral Raman , Humanos , Queimaduras/complicações , Queimaduras/metabolismo , Análise Espectral Raman/métodos , Vesículas Extracelulares/metabolismo , Sepse/metabolismo , Sepse/sangue , Biomarcadores/sangue , Biomarcadores/metabolismo , Feminino , Masculino , Adulto , Pessoa de Meia-IdadeRESUMO
An innovative method is introduced based on the combination of label-free surface-enhanced Raman scattering with advanced multivariate analysis. This technique allows both quantitative and qualitative assessment of Salmonella typhimurium and Escherichia coli on eggshells. Using silver nanocubes embedded in polydimethylsiloxane, we consistently achieved Raman spectra of bacteria. The stability of the Ag NCs@PDMS substrate is confirmed using rhodamine 6G over 30 days under standard conditions. Principal component analysis (PCA) effectively distinguishes between S. typhimurium and E. coli spectra. Partial least squares regression (PLS) models were developed for quantitative determination of bacteria on egg surfaces, yielding accurate results with minimal error. The S. typhimurium model achieves Rc2 = 0.9563 and RMSEC = 0.601 in calibration, and Rv2 = 0.9113 and RMSEV = 0.907 in validation. Similarly, the E. coli model achieves Rc2 = 0.9877 and RMSEC = 0.322 in calibration, and Rv2 = 0.9606 and RMSEV = 0.579 in validation. Recoveries validate PLS predictions by inoculating egg surfaces with varying bacterial amounts. Our study demonstrates the feasibility of SERS-PLS for quantitative determination of S. typhimurium and E. coli on eggshells, promising enhanced food safety protocols.
Assuntos
Dimetilpolisiloxanos , Ovos , Escherichia coli , Nanopartículas Metálicas , Salmonella typhimurium , Prata , Análise Espectral Raman , Análise Espectral Raman/métodos , Prata/química , Salmonella typhimurium/isolamento & purificação , Escherichia coli/isolamento & purificação , Nanopartículas Metálicas/química , Dimetilpolisiloxanos/química , Ovos/microbiologia , Animais , Microbiologia de Alimentos/métodos , Casca de Ovo/microbiologia , Casca de Ovo/química , Análise de Componente Principal , Contaminação de Alimentos/análiseRESUMO
This study describes the in-vitro cytotoxic effects of PEG-400 (Polyethylene glycol-400)-capped platinum nanoparticles (PEGylated Pt NPs) on both normal and cancer cell lines. Structural characterization was carried out using x-ray diffraction and Raman spectroscopy with an average crystallite size 5.7 nm, and morphological assessment using Scanning electron microscopy (SEM) revealed the presence of spherical platinum nanoparticles. The results of energy-dispersive x-ray spectroscopy (EDX) showed a higher percentage fraction of platinum content by weight, along with carbon and oxygen, which are expected from the capping agent, confirming the purity of the platinum sample. The dynamic light scattering experiment revealed an average hydrodynamic diameter of 353.6 nm for the PEGylated Pt NPs. The cytotoxicity profile of PEGylated Pt NPs was assessed on a normal cell line (L929) and a breast cancer cell line (MCF-7) using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results revealed an IC50of 79.18 µg ml-1on the cancer cell line and non-toxic behaviour on the normal cell line. In the dual staining apoptosis assay, it was observed that the mortality of cells cultured in conjunction with platinum nanoparticles intensified and the proliferative activity of MCF-7 cells gradually diminished over time in correlation with the increasing concentration of the PEGylated Pt NPs sample. Thein vitroDCFH-DA assay for oxidative stress assessment in nanoparticle-treated cells unveiled the mechanistic background of the anticancer activity of PEGylated platinum nanoparticles as ROS-assisted mitochondrial dysfunction.
Assuntos
Antineoplásicos , Apoptose , Neoplasias da Mama , Nanopartículas Metálicas , Platina , Polietilenoglicóis , Humanos , Polietilenoglicóis/química , Platina/química , Platina/farmacologia , Nanopartículas Metálicas/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Células MCF-7 , Feminino , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Difração de Raios X , Análise Espectral Raman/métodos , Tamanho da Partícula , Animais , Camundongos , Proliferação de Células/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Microscopia Eletrônica de VarreduraRESUMO
Osteoporosis (OP) is a chronic disease characterized by diminished bone mass and structural deterioration, ultimately leading to compromised bone strength and an increased risk of fractures. Diagnosis primarily relies on medical imaging findings and clinical symptoms. This study aims to explore an adjunctive diagnostic technique for OP based on surface-enhanced Raman scattering (SERS). Serum SERS spectra from the normal, low bone density, and osteoporosis groups were analyzed to discern OP-related expression profiles. This study utilized partial least squares (PLS) and support vector machine (SVM) algorithms to establish an OP diagnostic model. The combination of Raman peak assignments and spectral difference analysis reflected biochemical changes associated with OP, including amino acids, carbohydrates, and collagen. Using the PLS-SVM approach, sensitivity, specificity, and accuracy for screening OP were determined to be 77.78%, 100%, and 88.24%, respectively. This study demonstrates the substantial potential of SERS as an adjunctive diagnostic technology for OP.
Assuntos
Osteoporose , Análise Espectral Raman , Análise Espectral Raman/métodos , Humanos , Osteoporose/diagnóstico , Osteoporose/diagnóstico por imagem , Feminino , Pessoa de Meia-Idade , Máquina de Vetores de Suporte , Idoso , Análise dos Mínimos Quadrados , Masculino , Adulto , Densidade ÓsseaRESUMO
BACKGROUND: Metronidazole is a first-line antibiotic to treat Helicobacter pylori infections. However, the Clinical Laboratory Standards Institute guidelines recommend against using antimicrobial susceptibility test (AST) to test metronidazole resistance, due to the unreliable predictive power which can result in treatment failure. OBJECTIVES: The aim of this study was to establish an 8-h, metabolic-phenotype based AST for H. pylori metronidazole susceptibility using D2O-probed Raman microspectroscopy. METHODS: Minimal inhibitory concentration (MIC) measured by conventional AST (E-test) were compared with expedited MIC via metabolic activity (eMIC-MA) for 10 H. pylori isolates. Raman barcodes of cellular-response to stress (RBCS) incorporating protein and carbohydrate Raman bands, were utilized to identify a biomarker to distinguish metronidazole susceptibility. RESULTS: Specifically, eMIC-MA produces metronidazole susceptibility results showing 100% agreement with E-test, and determines the bactericidal dosage for both high- and low-level resistant H. pylori strains. In addition, RBCS not just reliably distinguish between metronidazole-susceptible and -resistant strains, but reveal their distinct mechanisms in bacterial responses to metronidazole. CONCLUSION: The speed, accuracy, low cost, and rich information content that reveals the mode-of-action of drugs suggest the method's value in guiding metronidazole prescriptions for H. pylori eradication and in rapid screening based on drug-resistance mechanism.
Assuntos
Antibacterianos , Infecções por Helicobacter , Helicobacter pylori , Metronidazol , Testes de Sensibilidade Microbiana , Análise Espectral Raman , Helicobacter pylori/efeitos dos fármacos , Metronidazol/farmacologia , Análise Espectral Raman/métodos , Testes de Sensibilidade Microbiana/métodos , Humanos , Antibacterianos/farmacologia , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/diagnóstico , Análise de Célula Única/métodos , Farmacorresistência BacterianaRESUMO
Small-molecule biomarkers are ubiquitous in biological fluids with pathological implications, but major challenges persist in their quantitative analysis directly in complex clinical samples. Herein, a molecular-sieving label-free surface-enhanced Raman spectroscopy (SERS) biosensor is reported for selective quantitative analysis of trace small-molecule trimetazidine (TMZ) in clinical samples. Our biosensor is fabricated by decorating a superhydrophobic monolayer of microporous metal-organic frameworks (MOF) shell-coated Au nanostar nanoparticles on a silicon substrate. The design strategy principally combines the hydrophobic surface-enabled physical confinement and preconcentration, MOF-assisted molecular enrichment and sieving of small molecules, and sensitive SERS detection. Our biosensor utilizes such a "molecular confinement-and-sieving" strategy to achieve a five orders-of-magnitude dynamic detection range and a limit of detection of ≈0.5 nM for TMZ detection in either urine or whole blood. We further demonstrate the applicability of our biosensing platform for longitudinal label-free SERS detection of the TMZ level directly in clinical samples in a mouse model.
Assuntos
Técnicas Biossensoriais , Ouro , Nanopartículas Metálicas , Estruturas Metalorgânicas , Análise Espectral Raman , Análise Espectral Raman/métodos , Animais , Camundongos , Ouro/química , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Humanos , Estruturas Metalorgânicas/química , Biomarcadores/urina , Biomarcadores/análise , Propriedades de Superfície , Limite de DetecçãoRESUMO
Rationale: Stroke induces metabolic changes in the body, and metabolites have become potential biomarkers for stroke. However, the specific metabolites involved in stroke and the mechanisms underlying brain injury during stroke remain unclear. Methods: Surface-enhanced Raman spectroscopy (SERS) and liquid chromatography-mass spectrometry (LCâMS) analysis of clinical serum samples from 69 controls and 51 ischemic stroke patients who underwent reperfusion within 24 hours were performed to identify differentially abundant metabolites. Mice were subjected to transient middle cerebral artery occlusion (tMCAO) and then intravenously injected with hypoxanthine. The infarct area was evaluated via tetrazolium chloride (TTC) staining, and behavior tests were conducted. Blood-brain barrier (BBB) leakage was assessed by Evans blue and IgG staining. Human blood vessel organoids were used to investigate the mechanism of hypoxanthine-induced pyroptosis of endothelial cells. Results: SERS and LCâMS revealed the metabolic profiles of serum from stroke patients and controls with high sensitivity, speed and accuracy. Hypoxanthine levels were significantly elevated in the acute stage of ischemic stroke in both patients and mice (p < 0.001 after Bonferroni correction). In addition, increasing hypoxanthine increased the infarct area and aggravated BBB leakage and neurobehavioral deficits in mice after ischemic stroke. Further mechanistic studies using endothelial cells, human blood vessel organoids, and stroke mice demonstrated that hypoxanthine-mediated gasdermin E (GSDME)-dependent pyroptosis of endothelial cells occurs through intracellular Ca2+ overload. Conclusion: Our study identified hypoxanthine as an important metabolite that induces vascular injury and BBB disruption in stroke through triggering GSDME-dependent pyroptosis of endothelial cells.