A Microfluidics-Based Multiplex SERS Immunoassay Device for Analysis of Acute Ischemic Stroke Biomarkers.

Sensitive and accurate methods for early detection of acute ischemic stroke (AIS) are essential for timely treatment and prognostic assessment of patients. In this study, we report a microfluidics-based ultrasensitive surface-enhanced Raman scattering (SERS) immunoassay device for the quantitative determination of multiplex biomarkers in AIS. By preparing 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) antibody-modified gold nanoparticles (AuNPs) on SERS devices as SERS probes, the biomarkers in whole blood of AIS were accurately captured and further visualized for SERS signal intensity quantitative analysis of six biomarkers in the blood samples. It is worth mentioning that the limit of detection (LOD) of the method can reach the level of fg/mL, with excellent sensitivity and selectivity. Meanwhile, the analytical comparison with ELISA method showed that the detection results of both methods were consistent, which verified the feasibility of the assembled device. The SERS immunoassay device detection provides a powerful strategy for the prediction, early diagnosis and dynamic monitoring of prognosis of AIS with a wide range of clinical practice prospects.

Application of Nanotechnology-Based Products in Stroke.

Stroke is a disease with high disability and high mortality in the world. Due to the existence of the blood-brain barrier (BBB), complex brain structure, and numerous neural signal pathways, the treatment methods are limited, so new drugs and new treatments need to be developed urgently. Thankfully, the advent of nanotechnology offered a new opportunity for biomedical development because of the unique properties of nanoparticles that give them the ability to traverse the BBB and accumulate in relevant regions of the brain. More importantly, nanoparticles could be modified on the surface to meet a variety of specific properties that people need. Some could be used for effective drug delivery, including tissue plasminogen activator (tPA), neuroprotective agents, genes, and cytokines; some nanoparticles were used as contrast agents and biosensors in medical imaging for further diagnosis of stroke; some were used to track target cells for prognosis of stroke; and some were used to detect pathological markers of stroke that appear at different stages. This Review looks at the application and research progress of nanoparticles in the diagnosis and treatment of stroke, hoping to bring some help to researchers.

Label-free SERS ultrasensitive and universal detection of low back pain fingerprint based on SERS substrate.

Low back pain (LBP) seriously endangers human health and quality of life, and the detection of thoracolumbar fasciitis (TLF) is vital for the prevention and treatment of LBP. Surface-enhanced Raman scattering (SERS) is considered as a powerful technique for fingerprint detection due to the inherent richness of the spectral data. In this work, a novel SERS strategy based on a three-dimensional substrate was developed for fingerprint analysis for early diagnosis of TLF. A rat TLF model was established and the model was evaluated from the immunological and behavioral perspectives. Vibrational fingerprints were obtained by SERS testing of isolated fascial tissue and were used to explore the material changes during fasciitis. SERS spectra were analyzed using principal component analysis (PCA) that allowed unambiguous distinction and monitoring of component changes during TLF. Furthermore, in order to further clarify the occurrence and development of TLF, we combined clinical samples for analysis, and investigated the inflammatory factor expression levels of CRP and SAA in TLF. Our results demonstrated that tryptophan, phenylalanine and glycogen could unambiguously distinguish TLF as confirmed by SERS analysis, a method that is capable of noninvasive characterization of and diagnosis of TLF during LBP. We have provided a new tool that may promote in-depth study of the mechanism and treatment of fasciitis.

A novel electrochemical IL-6 sensor based on Au nanoparticles-modified platinum carbon electrode.

Introduction: Interleukin-6 (IL-6) is a multifunctional polypeptide cytokine composed of two glycoprotein chains, which plays an important role in many cellular reactions, pathological processes, diagnosis and treatment of diseases and so on. The detection of IL-6 plays a promising role in the cognition of clinical diseases. Methods: 4-mercaptobenzoic acid (4-MBA) was immobilized on the gold nanoparticles modified platinum carbon (PC) electrode with the linker IL-6 antibody, and finally formed an electrochemical sensor that specifically recognized IL-6. Through the highly specific antigen-antibody reaction, the IL-6 concentration of the samples to be detected. The performance of the sensor was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Results: The experimental results showed that the linear detection range of the sensor for IL-6 was 100 pg/mL-700 pg/mL and the detection limit was 3 pg/mL. In addition, the sensor had the advantages of high specificity, high sensitivity, high stability and reproducibility under the interference environment of bovine serum albumin (BSA), glutathione (GSH), glycine (Gly) and neuron specific enolase (NSE), which provided a prospect for specific antigen detection sensor. Discussion: The prepared electrochemical sensor successfully detected the content of IL-6 in standard and biological samples, showing excellent detection performance. No significant difference was found between the detection results of the sensor and that of ELISA. The sensor showed a very broad prospect in the application and detection of clinical samples.

Selenium-Chromium(VI) Interaction Regulates the Contents and Correlations of Trace Elements in Chicken Brain and Serum.

This study aims to investigate the contents of trace elements in the brain and serum of male chickens and the effect of selenium-chromium(VI) interaction. A chronic experimental model was established by supplementing 22.14 mg/kg K2Cr2O7 with 0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg/kg Na2SeO3 mg/kg B.W. to water for chicken daily. After 14, 28, and 42 days of exposure to the solution, the brain and serum of chickens from each group were collected to detect the levels of Ca, Cu, Mn, Fe, Zn, and Mg by inductively coupled plasma mass spectrometer (ICP-MS). Cr(VI) time-dependently accumulated in the brain and serum. The contents of Cr increased both in the brain and serum with prolonged exposure. Cr contents in the brain and serum decreased in all Se groups compared with those in only Cr-treated groups. Ca contents decreased with prolonged exposure and increasing Se dosage. The contents of Cu and Mn increased on the 28th day but decreased on the 42nd day in the brain and serum. Fe and Zn contents decreased in the serum under prolonged exposure and increased on the 28th day but decreased on the 42nd day in the brain. Cr exposure did not significantly affect Mg contents in the brain but slightly decreased those in the serum. Therefore, appropriate doses of Se affected Cr accumulation, leading to adjustments in the contents and correlations of trace elements.

Effects of the Oral Administration of K2Cr2O7 and Na2SeO3 on Ca, Mg, Mn, Fe, Cu, and Zn Contents in the Heart, Liver, Spleen, and Kidney of Chickens.

This study aimed to investigate the effects of selenium on the ion profiles in the heart, liver, spleen, and kidney through the oral administration of hexavalent chromium. Approximately 22.14 mg/kg b.w. K2Cr2O7 was added to water to establish a chronic poisoning model. Different selenium levels (0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg Na2SeO3/kg b.w.) around the safe dose were administered to the experimental group model. Ca, Mg, Mn, Fe, Cu, and Zn were detected in the organs through flame atomic absorption spectrometry after these organs were exposed to K2Cr2O7 and Na2SeO3 for 14, 28, and 42 days. Results showed that these elements exhibited various changes. Ca contents declined in the heart, liver, and spleen. Ca contents also decreased on the 28th day and increased on the 42nd day in the kidney. Mn contents declined in the heart and spleen but increased in the kidney. Mn contents also decreased on the 28th day and increased on the 42nd day in the liver. Cu contents declined in the heart and spleen. Cu contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Zn contents declined in the heart and spleen. Zn contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Fe contents decreased in the heart and liver. Fe contents increased on the 28th day and decreased on the 42nd day in the spleen and kidney. Mg contents did not significantly change in these organs. Appropriate selenium contents enhanced Mn and Zn contents, which were declined by chromium. Conversely, appropriate selenium contents reduced Ca, Fe, and Cu contents, which were increased by chromium. In conclusion, the exposure of chickens to K2Cr2O7 induced changes in different trace elements, and Na2SeO3 supplementation could alleviate this condition.

Moderate selenium dosing inhibited chromium (VI) toxicity in chicken liver.

This study aimed to clarify the effect of selenium (Se) on chromium (VI) [Cr(VI)]-induced damage in chicken liver. A total of 105 chickens were randomly divided into seven groups of 15. Group I received deionized water; group II received Cr(VI) (7.83 mg/kg/d) alone; and other groups orally received both Cr(VI) (7.83 mg/kg/d) and Se of different doses (0.14, 0.29, 0.57, 1.14, and 2.28 mg/kg/d). The levels of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), Ca2+ -ATPase, and mitochondrial membrane potential (MMP) were measured. Results showed that Cr(VI) increased MDA content and decreased GSH content, T-SOD activity, Ca2+ -ATPase activity, and MMP level. Meanwhile, Se co-treatment (0.14, 0.29, and 0.57 mg/kg/d) increased the viability of the above indicators compared with Cr(VI)-treatment alone. In addition, histopathologic examination revealed that Cr(VI) can cause liver damage, whereas Se supplementation of moderate dose inhibited this damage. This study confirmed that Se exerted protective effect against Cr(VI)-induced liver damage.

Effect of various selenium doses on chromium(IV)-induced nephrotoxicity in a male chicken model.

Our study aimed to explore whether Na2SeO3 (Se) can alleviate the nephrotoxicity induced by K2Cr2O7 [Cr(VI)]. One hundred and five male chickens were randomly divided into seven groups with 15 chickens each group: The 6 experimental groups received K2Cr2O7 alone or in combination with 0.31, 0.63, 1.25, 2.50, and 5.00 mg/kg for 42 days, respectively, while control group was treated with equivalent water. Exposure to Cr(VI) significantly increased MDA contents and organ coefficient, whereas decreased T-SOD activities, Ca2+-ATPase activities, mitochondrial membrane potential and GSH contents, and histological studies demonstrated renal damage. Above indicators were restored by Se supplement (0.31, 0.63, and 1.25 mg/kg), in which supplement with 0.63 mg/kg Se developed more effectively than the other two groups; on the contrary, in the groups of Se supplement with 2.50 and 5.00 mg/kg, the above indicators were not ameliorated and even exacerbated. This study demonstrated that Cr(VI) can result in kidney oxidative damage in male chickens, and Se of certain dose has the protective effects against Cr(VI)-induced nephrptoxicity.

Characterization of polysaccharides extracted from Platycodon grandiflorus (Jacq.) A.DC. affecting activation of chicken peritoneal macrophages.

Polysaccharides were isolated from Platycodon grandiflorus (Jacq.) A.DC. (PG) and the effects of three polysaccharides (PGPS80, PGPS60, PGPSt) on their immunological activities were studied. The structure identification of PGPSs was assessed using physicochemical and spectral methods. Results showed that PGPSt(2.67×105Da) compared to PGPS80(1.01×105Da) and PGPS60(1.12×105Da) has relatively higher average molecular weight(Mw) at the first peak with a narrower molecular weight distribution and all consisted of glucose, mannose, arabinose, galactose, xylose and rhamnose in different mass percentages. PGPS80 and PGPSt linked mainly by 1,3-and 1,6-ß-d-Galp residues. The immunological efficacy of PGPSs was performed on chicken peritoneal macrophages. Results showed that PGPSt significantly increased phagocytic rates, proliferation and NO production, stimulated macrophages to produce cytokines, including TNF-α, IL-1ß and IL-6 as well as stimulated macrophages to express the maturation markers CD80 and CD86. These findings suggest that PGPSt exerted significant immunological activity and might be associated with special characters.

Selenium Administration Alleviates Toxicity of Chromium(VI) in the Chicken Brain.

Selenium (Se) can play a protective role against heavy metal toxicity. This experiment aims to evaluate the effect of Se supplementation at different doses on the chicken brains. Oxidative stress was induced in the chicken brains by chromium(VI). A total of 105 Hyland brown male chickens were randomly divided into seven groups, including the control group, poisoned group [6%LD50 K2Cr2O7 body weight (B.W.)], and detoxification groups K2Cr2O7 (6%LD50) + Se (0.31, 0.63, 1.25, 2.50, and 5.00 Na2SeO3 mg/kg B.W.) orally in water for 42 days. The chickens were detected by the activities of mitochondrial membrane potential, 2'-benzoyloxycinnamaldehyde, superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), and Ca2+-ATPase. Cr(VI) administration caused histopathological damage. In addition, changes in oxidative stress indicators were observed in the chicken's brains. Se supplement increased the levels of GSH, mitochondrial membrane potential (MMP), and Ca2+-ATPase and reduced MDA activity in the detoxification groups. However, the high-dose Se supplementation groups of 2.50 and 5.00 mg/kg reduced the activities of GSH, MMP, and Ca2+-ATPase; increased the brain-body ratio; and increased SOD activity. In conclusion, Cr(VI) exposure caused oxidative stress. Se exerted a remission effect on toxic responses in the chicken brains. However, a high Se concentration was synergistic to the toxic effect of Cr(VI).