Portable paper‐based device for quantitative colorimetric assays relying on light reflectance principle

This paper presents a novel paper‐based analytical device based on the colorimetric paper assays through its light reflectance. The device is portable, low cost (<20 dollars), and lightweight (only 176 g) that is available to assess the cost‐effectiveness and appropriateness of the original health care or on‐site detection information. Based on the light reflectance principle, the signal can be obtained directly, stably and user‐friendly in our device. We demonstrated the utility and broad applicability of this technique with measurements of different biological and pollution target samples (BSA, glucose, Fe, and nitrite). Moreover, the real samples of Fe (II) and nitrite in the local tap water were successfully analyzed, and compared with the standard UV absorption method, the quantitative results showed good performance, reproducibility, and reliability. This device could provide quantitative information very conveniently and show great potential to broad fields of resource‐limited analysis, medical diagnostics, and on‐site environmental detection.     

Fluorogenic probes for aldol reactions: tuning of fluorescence using π-conjugation systems

Fluorogenic aldehydes or probes for monitoring of the progress of aldol reactions have been developed. Fluorescence of benzaldehydes conjugated with aryl groups via a double or triple bond and of their aldol products was evaluated in aqueous solutions. Based on the fluorescence, fluorogenic aldol reaction substrates and retro-aldol reaction substrates were identified. Use of the probe system with optimal fluorescence properties for aldol reactions was demonstrated in assays with purified protein catalysts and with overproduced crude protein catalysts in cell lysates.     

基于表面等离子体子共振成像技术研究苏拉明和顺铂对肝癌细胞生长的抑制作用简

基于表面等离子体子共振成像(SPRi)技术提出了一种实时、非标记的新型抗癌药物药效评估方法. 以聚二甲基硅氧烷(PDMS)为材料,制作了包含微柱结构的微流控芯片作为流通反应池,配合自行设计组装的SPRi生物传感器完成肿瘤细胞的特异性捕获及检测,研究了苏拉明和顺铂对肝癌细胞HepG2的生长抑制作用. 同时引入辅助验证实验,即采用常规八肽胆囊收缩素(简称CCK-8)法测定上述药物对肝癌细胞增殖的抑制作用. SPRi检测结果表明,苏拉明和顺铂能抑制肿瘤细胞HepG2增殖并呈现剂量、时间依赖关系.     

基于硼酸酯的19F磁共振分子探针的设计合成及活体深组织活性氧物种的激活响应成像

活性氧簇(ROS), 如过氧化氢, 在生物体内的各种生理和病理过程中发挥着重要作用. 生物体内活性氧簇水平的异常与多种疾病(炎症、 肿瘤和器官损伤等)密切相关, 使ROS监测成为研究和诊断这些疾病的重要工具. 目前, 实现活体内深组织中的活性氧簇成像仍然面临挑战. 本文设计并合成了一种响应型的¹⁹F磁共振成像(MRI)探针(Gd-DPBF), 并将其用于实现对活体内通用活性氧簇的检测和成像. 该探针由钆螯合物通过活性氧簇响应的芳香硼酸酯键与含氟砌块相连接构成. 体外和体内成像实验结果证实, 该探针可以实现在活体荷瘤小鼠中针对肿瘤中高表达的活性氧进行检测和成像, 展示了其在生物体内对活性氧簇相关生理过程进行深组织、 零生物背景成像方面的潜力.     

Analysis of drug interactions with serum proteins and related binding agents by affinity capillary electrophoresis: A review

Biomolecules such as serum proteins can interact with drugs in the body and influence their pharmaceutical effects. Specific and precise methods that analyze these interactions are critical for drug development or monitoring and for diagnostic purposes. Affinity capillary electrophoresis (ACE) is one technique that can be used to examine the binding between drugs and serum proteins, or other agents found in serum or blood. This article will review the basic principles of ACE, along with related affinity-based capillary electrophoresis (CE) methods, and examine recent developments that have occurred in this field as related to the characterization of drug–protein interactions. An overview will be given of the various formats that can be used in ACE and CE for such work, including the relative advantages or weaknesses of each approach. Various applications of ACE and affinity-based CE methods for the analysis of drug interactions with serum proteins and other binding agents will also be presented. Applications of ACE and related techniques that will be discussed include drug interaction studies with serum agents, chiral drug separations employing serum proteins, and the use of CE in hybrid methods to characterize drug binding with serum proteins.     

Approaches for the detection and analysis of antidrug antibodies to biopharmaceuticals: A review

Antibody-based therapeutic agents and other biopharmaceuticals are now used in the treatment of many diseases. However, when these biopharmaceuticals are administrated to patients, an immune reaction may occur that can reduce the drug's efficacy and lead to adverse side-effects. The immunogenicity of biopharmaceuticals can be evaluated by detecting and measuring antibodies that have been produced against these drugs, or antidrug antibodies. Methods for antidrug antibody detection and analysis can be important during the selection of a therapeutic approach based on such drugs and is crucial when developing and testing new biopharmaceuticals. This review examines approaches that have been used for antidrug antibody detection, measurement, and characterization. Many of these approaches are based on immunoassays and antigen binding tests, including homogeneous mobility shift assays. Other techniques that have been used for the analysis of antidrug antibodies are capillary electrophoresis, reporter gene assays, surface plasmon resonance spectroscopy, and liquid chromatography-mass spectrometry. The general principles of each approach will be discussed, along with their recent applications with regards to antidrug antibody analysis.     

Jute stick extract assisted hydrothermal synthesis of zinc oxide nanoflakes and their enhanced photocatalytic and antibacterial efficacy

In this paper, we used green and hydrothermal methodology to prepare zinc oxide (ZnO) nanoflakes (NFs) with jute stick extract (J–ZnO NFs) as growth substrate. The prepared materials were characterized using different analytical techniques including ultraviolet–visible spectroscopy (UV–vis), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The characteristic absorption peak for ZnO NFs and J–ZnO NFs were observed from the UV–vis spectrum at 373 and 368 nm respectively. The hexagonal wurtzite crystal structure of ZnO NFs and J–ZnO NFs was confirmed by XRD analysis. FESEM and TEM analyses of synthesized J–ZnO NFs confirmed their NFs shape and collectively flower-like structure formation by the assembly of NFs of J–ZnO on cellulose of jute stick extract substrate. The FTIR analysis revealed the functional groups of jute stick extract biomolecules, mainly cellulose, are responsible for the formation of collectivel flower like J–ZnO NFs structure. The XPS analysis revealed the surface and chemical compositions (Zn, C, and O) of J–ZnO NFs. The photocatalytic performance of ZnO NFs and J–ZnO NFs samples was carried out by the degradation of methylene blue (MB) dye solution under UV light irradiation. The degradation efficiency of ZnO NFs and J–ZnO NFs was obtained 79 % and 89 %, respectively, for 5 h. Notably, the degradation efficiency of the J–ZnO NFs was 98 % after 8 h of irradiation, which is very inspiring. The both NFs exhibited first-order kinetics with MB photodegradation. We also examined the possible antibacterial activity of both samples against Escherichia coli (E. coli) pathogens, which demonstrated a significant result with a 17 mm and 19 mm zone of inhibition by ZnO NFs and J–ZnO NFs respectively.     

Evaluation of in vitro,in silico antidiabetic and antioxidant potential of bioactivity based isolated “Pakistanine” from Berberis baluchistanica

Bioassay based fractionation of methanolic extract of Berberis baluchistanica (Berberidaceae), used traditionally for internal injuries, led to the isolation of known compounds (1–4). The structure of these compounds was elucidated by different spectroscopic analysis and available literature data. Antidiabetic and antioxidant potentials of B. baluchistanica fractions and isolated compounds were evaluated using in vitro alpha- amylase and DPPH assays. The isolated compounds were identified as obamegine (1), pakistanine (2), 8-oxyberberine (3) and baluchistine (4). Obamegine was reported from many other species of this genus but it is first time isolated from B. baluchistanica in present study. Moreover, in vitro pakistanine (2) was found as bioactive lead molecule for hypoglycemic (IC₅₀:40.26 µg/ml) and antioxidant (IC₅₀:14.15 µg/ml) activities compared to acarbose (IC₅₀:33.68 µg/ml) and ascorbic acid (IC₅₀:0.41 µg/ml). To the best of our knowledge, no previous data were available for these biological activities. Additionally, in silico antidiabetic and antioxidant activity of pakistanine against two proteins, α-amylase (-9.7 kcal/mol) and tyrosinase (-8.7 kcal/mol) are reported here for the first time. The molecular docking binding interactions authenticate and support the above-mentioned activities and are helpful in predicting the mechanism of action of pakistanine (2).     

Spectrochemical analysis using LIBS and ICP-OES techniques of herbal medicine (Tinnevelly Senna leaves) and its anti-cancerous/antibacterial applications

Tinnevelly senna leaves are being applied to cure many diseases especially in developing countries and sub-Saharan region due to many bioactive compounds such as sennosides, phenols, and flavonoids. The conventional methods to isolate and analyze plant extracts biomolecules are not very effective as well cost effective as they require hazardous chemical solvents and reagents, which are time-consuming processes. The major objective of the present study is to investigate the feasibility of the Laser induced breakdown spectroscopy (LIBS) technique for rapid, eco-friendly, and multi-elemental analysis of Senna leaves extracts and study their antibacterial and anticancer potentials. The elegant LIBS technique was applied as a qualitative and quantitative method for Senna leaves sample’s elemental analysis and their biological activities were measured by evaluating anti-cancer and anti-bacterial analysis. The quantitative analysis of Senna leaves extracts was done using the calibration-free laser-induced breakdown spectroscopy (CF-LIBS) algorithm showing their appreciable content of several nutrient elements, and the obtained results were in close conformity with these achieved by using the standard analytical ICP OES technique. We studied the bactericidal efficacy of the Senna leaves extract against Staphylococcus aureus (S. aureus) by AWD assays and morphogenesis by scanning electron microscopy (SEM) and the anticancer activity was also investigated where different concentrations of Senna leaves extract were tested on cancer cells (HCT-116 and HeLa) and normal cells (HEK-293) using the cell metabolic activity MTT assay and Propidium iodide (PI) staining. We have also calculated the inhibitory concentration (IC50) value for the various extracts concentrations (25 µg/ml, 50 µg/ml, 100 µg/ml, 150 µg/ml, 200 µg/ml, and 225 µg/ml). We have found that IC₅₀ value for HCT-116 cells were 13.5 µg/ml, 17.5 µg/ml, 21.5 µg/ml, 22.5 µg/ml, 26 µg/ml and 33.5 µg/ml and for HeLa cells 15.25 µg/ml, 21.25 µg/ml, 23.5 µg/ml, 262.5 µg/ml, 36.25 µg/ml, and 39.50 µg/ml. The bactericidal efficacy of the Senna leaves extract showed significant inhibition against Gram-positive bacterium. Both MTT and PI analysis showed that Senna leaves extract induced profound inhibition on HCT-116 growth and proliferation. Additionally, Senna leaves extract did not exert an inhibitory influence on normal (HEK-293), which is non-cancerous cells. We suggest that the extract specifically targets the cancerous cells, which could be highly beneficial for the development of future safe anticancer and antibacterial drugs using these extracts.