Recent Development of Active Ingredients in Mouthwashes and Toothpastes for Periodontal Diseases

Periodontal diseases like gingivitis and periodontitis are primarily caused by dental plaque. Several antiplaque and anti-microbial agents have been successfully incorporated into toothpastes and mouthwashes to control plaque biofilms and to prevent and treat gingivitis and periodontitis. The aim of this article was to review recent developments in the antiplaque, anti-gingivitis, and anti-periodontitis properties of some common compounds in toothpastes and mouthwashes by evaluating basic and clinical studies, especially the ones published in the past five years. The common active ingredients in toothpastes and mouthwashes included in this review are chlorhexidine, cetylpyridinium chloride, sodium fluoride, stannous fluoride, stannous chloride, zinc oxide, zinc chloride, and two herbs—licorice and curcumin. We believe this comprehensive review will provide useful up-to-date information for dental care professionals and the general public regarding the major oral care products on the market that are in daily use.     

Rapid Sample Screening Method for Authenticity Controlling of Vanilla Flavours Using Liquid Chromatography with Electrochemical Detection Using Aluminium-Doped Zirconia Nanoparticles-Modified Electrode

A rapid and sensitive technique for frauds determination in vanilla flavors was developed. The method comprises separation by liquid chromatography followed by an electrochemical detection using a homemade screen-printed carbon electrode modified with aluminium-doped zirconia nanoparticles (Al-ZrO₂-NPs/SPCE). The prepared nanomaterials (Al-ZrO₂-NPs) were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX). This method allows for the determination of six phenolic compounds of vanilla flavors, namely, vanillin, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillyl alcohol, vanillic acid and ethyl vanillin in a linear range between 0.5 and 25 µg g⁻¹, with relative standard deviation values from 2.89 to 4.76%. Meanwhile, the limits of detection and quantification were in the range of 0.10 to 0.14 µg g⁻¹ and 0.33 to 0.48 µg g⁻¹, respectively. In addition, the Al-ZrO₂-NPs/SPCE method displayed a good reproducibility, high sensitivity, and good selectivity towards the determination of the vanilla phenolic compounds, making it suitable for the determination of vanilla phenolic compounds in vanilla real extracts products.     

LIBS结合图像筛选方法提高钢铁中Cu、Cr、Mn元素检测稳定性研究

优质特种钢材和低端粗钢之间的性能差异主要受其构成元素种类及其成分含量的影响,因此,如何快速准确地对物质成分进行定性及定量分析对钢铁产品的质量评估至关重要。针对传统方法难以实现对钢铁合金成分的快速准确检测的难题,采用激光诱导击穿光谱(LIBS)结合等离子体图像信息的方法,通过快速地对不同元素的特征光谱强度与激发生成的等离子体图像进行采集,分析两者之间的相关性,并通过提取的图像特征信息的异常值剔除了部分无效光谱数据,进而实现了对钢铁成分的高精度分析。通过分析延迟时间和激光能量等不同实验条件对元素特征光谱强度及其对应等离子体图像的影响规律,不仅证明了等离子体图像与光谱之间存在相关性,还利用等离子体图像特征信息的局部最优值确定了最优延迟时间、激光能量分别为1 000 ns与50 mJ,并根据图像特征的平均阈值来筛选无效光谱数据。结果表明,图像筛选优化数据后,各元素谱线校准模型的决定系数(R²)分别从原始数据的0.978、0.986、0.957、0.935提升至0.995、0.997、0.968、0.957,且其定标曲线对未知样品元素的预测浓度相对标准偏差(RSD)下降为原...     

Screening for Oral Cancer Using Electrochemical Telomerase Assay

Electrochemical telomerase assay (ECTA) developed by our group was evaluated in an oral cancer screening using exfoliated oral cells and tissues obtained from patients of oral cancer, mucosa associated disease, or healthy volunteers. Telomerase activity from ECTA is correlated with hTERT mRNA expression level using a real‐time PCR and was increasing in the following order: healthy volunteer group<mucosa associated disease group<oral cancer group. Sensitivity and specificity of ECTA were 88 % and 72 %, respectively when used 17 % of the threshold value based on the receiver operating characteristic curve in ECTA data.     

Lipid-Based Nanostructures for the Delivery of Natural Antimicrobials

Encapsulation can be a suitable strategy to protect natural antimicrobial substances against some harsh conditions of processing and storage and to provide efficient formulations for antimicrobial delivery. Lipid-based nanostructures, including liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid nanocarriers (NLCs), are valuable systems for the delivery and controlled release of natural antimicrobial substances. These nanostructures have been used as carriers for bacteriocins and other antimicrobial peptides, antimicrobial enzymes, essential oils, and antimicrobial phytochemicals. Most studies are conducted with liposomes, although the potential of SLNs and NLCs as antimicrobial nanocarriers is not yet fully established. Some studies reveal that lipid-based formulations can be used for co-encapsulation of natural antimicrobials, improving their potential to control microbial pathogens.     

On-Line HPLC with Biochemical Detection for Screening Bioactive Compounds in Complex Matrixes

On-line high-performance liquid chromatography (HPLC) coupled with biochemical detection (BCD) has been developed to screen compounds showing antioxidant action, enzyme inhibition and receptor affinity in complex matrixes. This review summarizes HPLC methods combining different post-column detection methods, such as diode-array detection (DAD), mass spectrometry (MS), chemiluminescence (CL) and nuclear magnetic resonance, for antioxidant screening. The methods based on a single relatively stable reagent such as DPPH^• and ABTS^•+ were the most popular. Oxygen free radical scavengers mainly depended on post-column CL detection. The on-line hyphenated HPLC–BCD systems based on post-column UV/DAD fluorescence and MS detection were also widely applied to screen enzyme- and receptor-active compounds. These strategies provide a convenient tool for quick identification and quantification of active compounds in complex matrixes.

     

Aminoglycoside Conjugation for RNA Targeting: Antimicrobials and Beyond

Natural aminoglycosides are therapeutically useful antibiotics and very efficient RNA ligands. They are oligosaccharides that contain several ammonium groups able to interfere with the translation process in prokaryotes upon binding to bacterial ribosomal RNA (rRNA), and thus, impairing protein synthesis. Even if aminoglycosides are commonly used in therapy, these RNA binders lack selectivity and are able to bind to a wide number of RNA sequences/structures. This is one of the reasons for their toxicity and limited applications in therapy. At the same time, the ability of aminoglycosides to bind to various RNAs renders them a great source of inspiration for the synthesis of new binders with improved affinity and specificity toward several therapeutically relevant RNA targets. Thus, a number of studies have been performed on these complex and highly functionalized compounds, leading to the development of various synthetic methodologies toward the synthesis of conjugated aminoglycosides. The aim of this review is to highlight recent progress in the field of aminoglycoside conjugation, paying particular attention to modifications performed toward the improvement of affinity and especially to the selectivity of the resulting compounds. This will help readers to understand how to introduce a desired chemical modification for future developments of RNA ligands as antibiotics, antiviral, and anticancer compounds.     

聚中性红修饰玻碳电极的制备及其在抗菌药物有效性检测中的应用

采用电聚合法制备了聚中性红修饰玻碳电极(PNR/GCE),运用循环伏安法(CV)对修饰电极进行表征,并以CV图中的峰电流为指标,研究了中性红浓度、扫描段数、缓冲液pH值及支持电解质NaNO_3浓度对聚合过程的影响,筛选了最佳聚合条件。继而借助中性红可作为电子媒介体的特性,以E.coli为模型微生物,通过考察E.coli活性与抗菌药物浓度的关系,构建了一种新型体外药效检测的方法,用于抗菌药物有效性的快速检测。以中性红浓度0.5 mmol/L,扫描段数Segment 30,缓冲液pH 7.0,NaNO_3浓度0.5 mol/L为最佳电极修饰条件。选择菌悬液吸光度(OD_(600)) 0.5,反应时间40 min,以标准葡萄糖-谷氨酸溶液(GGA,BOD~(220))为营养物质,此时检测抗菌药物有效性的灵敏度最高。在最佳实验条件下,头孢哌酮、阿米卡星、庆大霉素、左氧氟沙星4种抗菌药物对E.coli的半数抑菌浓度分别为34.15、27.98、8.83、11.49 mg/L;作为抗革兰氏阳性菌的万古霉素对E.coli的抑菌效果较差。上述结果与经典纸片扩散法具有良好一致性。     

Screening for Protein Phosphorylation Using Nanoscale Reactions on Microdroplet Arrays

We present a novel and straightforward screening method to detect protein phosphorylations in complex protein mixtures. A proteolytic digest is separated by a conventional nanoscale liquid chromatography (nano‐LC) separation and the eluate is immediately compartmentalized into microdroplets, which are spotted on a microarray MALDI plate. Subsequently, the enzyme alkaline phosphatase is applied to every second microarray spot to remove the phosphate groups from phosphorylated peptides, which results in a mass shift of n×?80 Da. The MALDI‐MS scan of the microarray is then evaluated by a software algorithm to automatically identify the phosphorylated peptides by exploiting the characteristic chromatographic peak profile induced by the phosphatase treatment. This screening method does not require extensive MS/MS experiments or peak list evaluation and can be easily extended to other enzymatic or chemical reactions.     

血浆和尿中苯并二氮杂（艹卓）类药物及其代谢物的电子捕获气相色谱筛选分析法

建立了血浆和尿中 11种苯并二氮杂类药物及其 9种代谢物的电子捕获检测气相色谱分析方法。血浆及加 β 葡萄糖醛酸酶水解后的尿在碱性条件下用苯 异戊醇 (98.5∶1.5 )提取 ,提取物非衍生化或三甲硅烷基衍生化后进行色谱分析。分析采用两根极性不同的色谱柱。检材中分析物的检出限大多数低于 10 μg/L,本方法还可用于定量分析。自愿者服口服治疗量药物 ,其血浆、尿中药物和代谢物的分析结果表明 :本方法实用于麻醉抢劫案中的药物分析     

尿和血浆中苯并二氮杂卓类药物及其代谢物的气相色谱氮磷检测分析法

建立了尿和血浆中11种苯并二氮杂卓类药物和10种代谢物的气相色谱氮磷检测分析方法。血浆及加β-葡萄糖醛酸酶水解后的尿在碱性条件下用苯-异戊醇（98．5：1．5，V／V）提取，提取物用两根极性不同的色谱柱分析。分析物的检出限大多数低于10ng／mL。对口服治疗量药物自愿者血浆和尿中药物和代谢物分析的分析结果表明，本方法适用于麻醉犯罪案件中药物的分析。     

利用化学指示剂在多相催化反应中进行高通量筛选

 介绍了一种简单的组合化学技术,该技术利用催化反应中产物或反应物导致的化学指示剂的颜色变化快速地指示反应进程. 选用甲基橙为指示剂,分子筛为催化剂,考察了不同反应条件下羧酸的酯化反应,并用气相色谱和高效液相色谱分析方法对实验结果进行验证. 结果表明,利用化学指示剂进行的高通量颜色筛选结果与色谱检测结果很好地吻合,该方法具有简单和高效的特点,可应用于对化学指示剂敏感的反应.     

A New Bioautographic Screening Method for the Detection of Estrogenic Compounds

The yeast estrogen screen was introduced as biological detection method for high performance thin layer chromatography. Yeast cells were grown directly on HPTLC plates, where in the presence of estrogenic substances the production of the enzyme -galactosidase was induced. For the natural ligand 17 -estradiol, sensitivity could be improved by a factor of 20 using the fluorogenic substrate 4-methylumbelliferyl -D-galactopyranoside instead of the chromogenic substrate chlorophenol red--D-galactopyranoside. The fluorescence intensity of estrogenic zones was measured using a commercial TLC-Scanner. A nearly full dose-response curve was obtained for 17 -estradiol masses between 2.75 and 550 pg, or concentrations of 2.75 to 550 g L^–1.     

Fast Screening for Tobacco-Specific N-nitrosamines by CZE Using Dynamically Coated Capillaries

In this paper, we propose a rapid capillary zone electrophoretic method with dynamically coated capillaries for separation of and screening for six tobacco-specific nitrosamines, a group of strong carcinogens found only in tobacco products. Dynamic coating of the capillary surface with a polycation coating (CElixir Reagent A) followed by a polyanion coating (CElixir Reagent B; pH 2.5) was accomplished by use of a commercially available reagent kit. With this method, six tobacco-specific nitrosamines: N??-nitrosonornicotine, N??-nitrosoanatabine, N??-nitrosoanabasine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, and 4-(methylnitroamino)-4-(3-pyridyl)-1-butanol were simultaneously separated and determined within 3 min, with a satisfactory detection limit of 1.0 ??g mL^?1 for all the tobacco-specific nitrosamines at S/N = 3, and a linear relationship between UV absorbance and analyte concentration (R ² > 0.98). The repeatability of the method ranged from 0.24 to 0.73% (RSD, n = 5) for migration time and 0.25?C1.54% (RSD, n = 5) for peak area, demonstrating that this capillary electrophoretic method is better than conventional capillary zone electrophoresis.     

Strategies Using Gelatin Microparticles for Regenerative Therapy and Drug Screening Applications

Gelatin, a denatured form of collagen, is an attractive biomaterial for biotechnology. In particular, gelatin particles have been noted due to their attractive properties as drug carriers. The drug release from gelatin particles can be easily controlled by the crosslinking degree of gelatin molecule, responding to the purpose of the research. The gelatin particles capable of drug release are effective in wound healing, drug screening models. For example, a sustained release of growth factors for tissue regeneration at the injured sites can heal a wound. In the case of the drug screening model, a tissue-like model composed of cells with high activity by the sustained release of drug or growth factor provides reliable results of drug effects. Gelatin particles are effective in drug delivery and the culture of spheroids or cell sheets because the particles prevent hypoxia-derived cell death. This review introduces recent research on gelatin microparticles-based strategies for regenerative therapy and drug screening models.     

Preliminary Screening Method for Dioxin Contamination Using Polarization Fluoroimmunoassay for Chlorinated Phenoxyacid Pesticides

Polarization fluoroimmunoassays (PFIA) were developed for the chlorinated pesticides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). In order to optimize the PFIA procedures, a number of fluorescein-labeled 2,4-D and 2,4,5-T derivatives were synthesized and the influence of their structures on PFIA characteristics was studied. Also, several antisera were tested in developing the PFIA for 2,4,5-T. The assays were adapted for use with the Abbott TDx Analyzer and could be run in automatic mode by the adaptation of existing software and protocols. Dynamic ranges for 2,4-D and 2,4,5-T were 0.2-200 ng mL^–1 and 30-10 000 ng mL^–1, respectively. Total time for the automated assay of 20 samples was about 22 min. PFIA provides a suitable means for screening of a large number of samples. The rapid determination of 2,4,5-T, which is one of the precursors of polychlorinated dibenzo-p-dioxins, one of the most toxic groups of pollutants, may potentially be used to provide preliminary evidence of dioxin contamination.