SERS-based detection of the antibiotic ceftriaxone in spiked fresh plasma and microdialysate matrix by using silver-functionalized silicon nanowire substrates.

Therapeutic drug monitoring (TDM) is an important tool in precision medicine as it allows estimating pharmacodynamic and pharmacokinetic effects of drugs in clinical settings. An accurate, fast and real-time determination of the drug concentrations in patients ensures fast decision-making processes at the bedside to optimize the clinical treatment. Surface-enhanced Raman spectroscopy (SERS), which is based on the application of metallic nanostructured substrates to amplify the inherent weak Raman signal, is a promising technique in medical research due to its molecular specificity and trace sensitivity accompanied with short detection times. Therefore, we developed a SERS-based detection scheme using silicon nanowires decorated with silver nanoparticles, fabricated by means of top-down etching combined with chemical deposition, to detect the antibiotic ceftriaxone (CRO) in spiked fresh plasma and microdialysis samples. We successfully detected CRO in both matrices with an LOD of 94 µM in protein-depleted fresh plasma and 1.4 µM in microdialysate.

In-situ and amplification-free imaging of hERG ion channels at single-cell level using a unique core-molecule-shell-secondary antibody SERS nanoprobe.

Research on ion channels and their monoclonal antibodies plays a critical role in drug development and disease diagnosis. The current ion channel researches are often not conducted in the microenvironment for cells survival, which restricts the mechanism study of the links between the cell structure and the ion channel function. In this work, we synthesized gold core-4-mercaptobenzonitrile-sliver shell-goat anti-rabbit immunoglobulin G (Au@4-MBN@Ag@IgG) nanoparticles as surface-enhanced Raman scattering (SERS) nanoprobes for investigating the human ether-a-go-go related gene (hERG) potassium ion channel in cell membranes. This is the first attempt to study ion channels using SERS. Due to the unique core-molecule-shell structure and the silver shell of nanoprobes, strong and stable SERS signal was obtained. With the help of antibodies, the Au@4-MBN@Ag@IgG nanoprobes were captured by hERG antibodies and then bonded with hERG ion channels based on the sandwich immune response. The reporter molecule, 4-MBN, displayed a strong and sharp characteristic peak at 2233 cm-1 in the Raman silent region. The intensity of this peak denoted the concentration of antibodies and the expression of ion channel proteins. We successfully applied this amplification-free method for in-situ imaging the distribution of the hERG ion channel on the transfected HEK293 cell surface at the single-cell level. This hERG ion channel profiling strategy promises a maneuverable tool for ion channel research.

A nanohybrid of Prussian blue supported by boracic acid-modified g-C3N4 for Raman recognition of cell surface sialic acid and photothermal/photodynamic therapy.

Theranostic nanoplatforms with accurate diagnosis and effective therapy show a bright prospect for tumor treatments. Herein, a novel boracic acid-modified graphite carbon nitride and Prussian blue nanohybrid (PB@B-g-C3N4) was developed, which provides sialic acid-targeted Raman recognition and synergistic photothermal/photodynamic therapy in the near-infrared region. Owing to the specific interaction between boracic acid and sialic acid and Raman response at 2157 cm-1 of PB, the nanohybrids exhibit high specificity and Raman sensitivity for detection of the overexpressed sialic acid on tumor cells. Moreover, the photothermal conversion efficiency of PB@B-g-C3N4 is as high as 47.0% with 808 nm laser irradiation due to the enhanced absorbance of PB@B-g-C3N4. PB@B-g-C3N4 also possesses excellent photodynamic activity, which is attributed to the energy transfer of PB (type I) and electron transfer between PB and B-g-C3N4 (type II). This nanotheranostic agent for Raman recognition of cancer markers and synergistic photothermal/photodynamic therapy holds great potential for the development of efficient theranostic nanoplatforms.

In situ monitoring PUVA therapy by using a cell-array chip-based SERS platform.

Psoralen ultraviolet A (PUVA) therapy has thrived as a promising treatment for psoriasis. However, overdose of PUVA treatment will cause side-effects, such as melanoma formation. And these side-effects are often ignored during PUVA therapy. Hence, in situ monitoring therapeutic response of PUVA therapy is important to minimize side-effects. Aberrant expression of tyrosinase (TYR) has been proved to be associated with melanoma, indicating that TYR is a potential target for evaluation of PUVA therapy. Herein, we reported a strategy for in situ monitoring TYR activity during PUVA therapy by using a cell-array chip-based SERS platform. The cell-array chip was used to simulate cell survival environment for cell culture. Capture of single cells and living cell analysis were realized in the isolated microchambers. An enzyme-induced core-shell self-assembly substrate was used to evaluate TYR activity in living cells during PUVA therapy. The gold nanoparticle modified with a SERS reporter, 4-mercaptobenzonitrile (4-MBN), was used as the core. In the presence of oxygen and TYR, hydroxylation of l-tyrosine occurred, leading to the reduction of silver ion on the surface of gold cores. The growth of silver shells was accompanied by the increased SERS intensity of the reporter, which is related directly to TYR activity. The detection limit for TYR activity is 0.45 U/mL. Upregulation of TYR activity was successfully monitored after PUVA therapy. Notably, real-time and in situ information of therapeutic response can be obtained through monitoring PUVA therapy by using a cell-array chip-based SERS platform, which has great potential to guide the clinical application of PUVA therapy.

[Multi-omics analysis of regulating effects of hyperoside on lipid metabolism in high-fat diet mice].

The aim of this study was to explore the regulating effects of hyperoside (Hyp) on lipid metabolism in high-fat diet mice. The high-fat diet mouse model was established by high-fat diet induction. After 5 weeks of Hyp intragastric administration in high-fat diet mice, the serum lipid levels before and after Hyp administration were measured by the corresponding kits. The tissue structure of mouse liver was observed by HE staining before and after Hyp administration. The changes of intestinal flora and transcriptome were measured by Illumina platforms. Liquid chromatography-mass spectrometry (LC-MS) was used to determine non-targeted metabolites. The results showed that Hyp significantly reduced lipid levels in the high-fat diet mice and effectively restored the external morphology and internal structure of liver tissue. Hyp changed the species composition of the intestinal flora in high-fat diet mice, increased the abundance of beneficial flora such as Ruminococcus, and decreased the abundance of harmful flora such as Sutterella. Combined multi-omics analysis revealed that the effect of retinoic acid on lipid metabolism was significant in the high-fat diet mice treated with Hyp, while the increase of retinoic acid content was significantly negatively correlated with the expression of genes such as cyp1a2 and ugt1a6b, positively correlated with AF12 abundance, and significantly negatively correlated with unidentified_Desulfovibrionaceae abundance. These results suggest that Hyp may modulate the abundance of AF12, unidentified_Desulfovibrionaceae and inhibit the expression of genes such as cyp1a2 and ugt1a6b, thus increasing the content of retinoic acid and regulating lipid metabolism in the high-fat diet mice.

Enhanced chemodynamic therapy at weak acidic pH based on g-C3N4-supported hemin/Au nanoplatform and cell apoptosis monitoring during treatment.

Chemodynamic therapy (CDT), inducing tumor cell apoptosis through Fenton reaction to produce hydroxyl radical (·OH), is an emerging cancer treatment technology. Highly efficient Fenton catalytic reactions usually take place at a low pH environment. Utilizing graphitic carbon nitride supported hemin and Au nanoparticles (g-C3N4/hemin/Au) as a novel biomimetic nanocatalyst, we achieve an enhanced CDT for inducing tumor cell apoptosis in the presence of excess H2O2, and reveal the molecular events during the CDT-induced apoptosis. The prepared g-C3N4/hemin/Au nanohybrids exhibit excellent Fenton catalytic activity for the generation of highly toxic ·OH at weak acidic and neutral condition, which breaks through the limitation of traditional acidity-dependent response. The Fenton catalytic mechanism was also studied. The Fenton efficiency is primarily enhanced by the high affinity between nanohybrids and H2O2, and the transformation of Fe(III) to Fe(IV)=O without the formation of iron hydrate precipitation. Moreover, the intracellular molecular events during the CDT process were monitored. Phenylalanine metabolism was perturbed with protein degradation and DNA structures were damaged, which eventually lead to cell apoptosis. This study provides a significant guidance for the further development of more effective CDT platforms.

High sensitivity and non-background SERS detection of endogenous hydrogen sulfide in living cells using core-shell nanoparticles.

Endogenous hydrogen sulfide (H2S) exists in multiple physiological processes. In order to further understand the action mechanism of H2S in cells and human body, we proposed a smart surface-enhanced Raman scattering (SERS) nanoprobe, Au core-4-mercaptobenzonitrile-Ag shell nanoparticle (Au@4-MBN@Ag), for the detection of endogenous H2S in living cells based on the reaction between Ag shell and sulfide species. 4-MBN was selected as the SERS reporter to avoid interference from cellular molecules. With the sulfide concentration increasing, the Ag2S constantly formed, and consequently the SERS signal intensity of Au@4-MBN@Ag gradually decreased owing to the weaker SERS activity of Ag2S. With the nanoprobes, this method not only offers a high sensitivity for H2S detection at an nM level, but also achieves the goal of non-background analysis. It displays satisfactory anti-interference capability and a good linear relationship with sulfide concentration ranging from 50 nM to 500 µM, and an estimated detection limit is 0.14 nM. The Au@4-MBN@Ag nanoprobes were successfully applied to detect endogenous H2S in living HepG2 cells stimulated by pyridoxal 5-phosphate monohydrate. This work offers a potential analytical method in the related research of H2S physiological function.

[Study on clinicopathologic grading system and prognosis of primary hepatic neuroendocrine neoplasms].

OBJECTIVE: To study the clinicopathologic features, criteria for grading and prognostic factors of primary hepatic neuroendocrine neoplasms. METHODS: Thirty-five cases of primary hepatic neuroendocrine neoplasm were retrieved from the archival files over a period of 11 years (with 32 cases having integrated data). According to the 2010 WHO classification of tumors of the digestive system, the cases were categorized into three groups: neuroendocrine tumor grade 1 (NET G1), neuroendocrine tumor grade 2 (NET G2) and neuroendocrine carcinoma (NEC). Statistical correlation between various histologic parameters and survival data was analyzed. RESULTS: Statistical analysis showed significant difference between NET [G1 (1 case)/G2 (14 cases)] and NEC (17 cases) groups in terms of tumor differentiation, necrosis, nuclear atypia, mitotic count and Ki-67 proliferative index (P < 0.05). There was no statistically significant difference in tumor size, growth pattern and presence of vascular tumor emboli (P > 0.05). The survival rate of patients correlated with tumor differentiation, growth pattern, necrosis, nuclear atypia, mitotic count and proliferative index (P < 0.05). There was no statistically significant difference between patient survival and tumor size or presence of vascular tumor emboli (P > 0.05). CONCLUSIONS: The subdivision of primary hepatic neuroendocrine neoplasm according to the 2010 WHO classification of tumors of the digestive system helps to evaluate the malignant potential and prognosis of the tumors. Prognostically useful histologic parameters include tumor differentiation, growth pattern, necrosis, nuclear atypia, mitotic count and proliferative index.