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.     

Brassinin inhibits proliferation and induces cell cycle arrest and apoptosis in nasopharyngeal cancer C666-1 cells

BackgroundNasopharyngeal cancer is a tumor that occurs in the mucous epithelium of the nasopharynx. Due to its rapid growth and early metastatic nature, the successful treatment of nasopharyngeal cancer is highly challenging.ObjectiveHere, we intended to assess the in vitro anticancer property of brassinin against the nasopharyngeal cancer C666-1 cells.MethodologyThe in vitro free radical scavenging property of the brassinin was assessed by various free radical scavenging activities such as FRAP, DPPH, chemiluminescence (CL), and ORAC assays. The cytotoxic level of the brassinin (1–50 µM) against the nasopharyngeal cancer C666-1 cells and normal Vero cells were assessed by the MTT cytotoxicity assay. The levels of TBARS, GSH, and the SOD activity was assessed using kits. The level of ROS generation, MMP, and apoptosis were investigated by the respective fluorescent staining techniques. The flow cytometry analysis was done to scrutinize the cell cycle arrest. The Bax/Bcl-2 level and caspase activities were examined using respective kits.ResultsThe brassinin treatment effectively scavenged the free radicals, which are assessed by the FRAP, DPPH, chemiluminescence (CL), and ORAC assays. The proliferation of brassinin treated C666-1 cells were decreased remarkably, while the same concentration of brassinin did not disturbed the Vero cell viability. The 30 µM of brassinin effectively increased the ROS production, depleted the MMP, and stimulated the apoptosis in the C666-1 cells. The brassinin increased the TBARS and depleted the GSH and SOD in the C666-1 cells. The flow cytometry analysis revealed that the brassinin administration improved the G0/G1 ratio and decreased the proportion of cells with ‘S’ and ‘G2/M’ phase. The Bax, caspase-3 and ?9 were elevated and Bcl-2 level was decreased in the brassinin administered C666-1 cells.ConclusionOur findings discovered that the brassinin has the capacity to prevent the proliferation and stimulate the apoptotic cell death C666‐1 cells via blocking cell cycle and increasing oxidative stress and apoptotic markers. Hence, it can be a talented therapeutic agent to treat the nasopharyngeal cancer in the future.     

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.     

Fabrication of a solution-processed thin-film transistor using zinc oxide nanoparticles and zinc acetate

We have fabricated a solution-processed ZnO thin-film transistor without vacuum deposition. ZnO nanoparticles were prepared by the polyol method from zinc acetate, polyvinyl pyrrolidone, and diethyleneglycol. The solution-processable semiconductor ink was prepared by dispersing the synthesized ZnO in a solvent. Inverted stagger type thin-film transistors were fabricated by spin casting the ZnO ink on the heavily doped Si wafer with 200 nm thick SiO₂, followed by evaporation of Cr/Au source and drain electrodes. After the drying and heat treatment at 600 C, a relatively dense ZnO film was obtained. The film characteristics were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In order to obtain the electrical properties of the solution-derived transistor, the on–off ratio, threshold voltage, and mobility were measured.     

Evaluation of ion mobility in capillary electrophoresis coupled to mass spectrometry for the identification in metabolomics

Currently, feature annotation remains one of the main challenges in untargeted metabolomics. In this context, the information provided by high-resolution mass spectrometry (HRMS) in addition to accurate mass can improve the quality of metabolite annotation, and MS/MS fragmentation patterns are widely used. Accurate mass and a separation index, such as retention time or effective mobility (μ_eff), in chromatographic and electrophoretic approaches, respectively, must be used for unequivocal metabolite identification. The possibility of measuring collision cross-section (CCS) values by using ion mobility (IM) is becoming increasingly popular in metabolomic studies thanks to the new generation of IM mass spectrometers. Based on their similar separation mechanisms involving electric field and the size of the compounds, the complementarity of ^DTCCS_N2 and μ_eff needs to be evaluated. In this study, a comparison of ^DTCCS_N2 and μ_eff was achieved in the context of feature identification ability in untargeted metabolomics by capillary zone electrophoresis (CZE) coupled with HRMS. This study confirms the high correlation of ^DTCCS_N2 with the mass of the studied metabolites as well as the orthogonality between accurate mass and μ_eff, making this combination particularly interesting for the identification of several endogenous metabolites. The use of IM-MS remains of great interest for facilitating the annotation of neutral metabolites present in the electroosmotic flow (EOF) that are poorly or not separated by CZE.     

Developments and applications of separation and microfluidics methods coupled to electrospray mass spectrometry in glycomics of nervous system gangliosides

Gangliosides are particularly abundant in the nervous system (NS) where their pattern and structure in a certain milieu or a defined region exhibit a pronounced specificity. Since gangliosides are useful biomarkers for diagnosis of NS ailments, a clear-cut mapping of individual components represents a prerequisite for designing ganglioside-based diagnostic procedures, treatments, or vaccines. These bioclinical aspects and the high diversity of ganglioside species claim for development of specific analytical strategies. This review summarizes the state-of-the-art in the implementation of separation techniques and microfluidics coupled to MS, which have contributed significantly to the advancement of the field. In the first part, the review discusses relevant approaches based on HPLC MS and CE coupled to ESI MS and their applications in the characterization of gangliosides expressed in healthy and diseased NS. A considerable section is dedicated to microfluidics MS and ion mobility separation MS, developed for the study of brain gangliosidome and its changes triggered by various factors, as well as for ganglioside biomarker discovery in neurodegenerative diseases and brain cancer. In the last part of the review, the benefits and perspectives in ganglioside research of these high-performance techniques are presented.     

Electrophoresis and electric conduction in a salt-free suspension of charged particles

The electrophoresis and electric conduction of a suspension of charged spherical particles in a salt-free solution are analyzed by using a unit cell model. The linearized Poisson-Boltzmann equation (valid for the cases of relatively low surface charge density or high volume fraction of the particles) and Laplace equation are solved for the equilibrium electric potential profile and its perturbation caused by the imposed electric field, respectively, in the fluid containing the counterions only around the particle, and the ionic continuity equation and modified Stokes equations are solved for the electrochemical potential energy and fluid flow fields, respectively. Explicit analytical formulas for the electrophoretic mobility of the particles and effective electric conductivity of the suspension are obtained, and the particle interaction effects on these transport properties are significant and interesting. The scaled zeta potential, electrophoretic mobility, and effective electric conductivity increase monotonically with an increase in the scaled surface charge density of the particles and in general decrease with an increase in the particle volume fraction, keeping each other parameter unchanged. Under the Debye-Hückel approximation, the dependence of the electrophoretic mobility normalized with the surface charge density on the ratio of the particle radius to the Debye screening length and particle volume fraction in a salt-free suspension is same as that in a salt-containing suspension, but the variation of the effective electric conductivity with the particle volume fraction in a salt-free suspension is found to be quite different from that in a suspension containing added electrolyte.     

The progress and perspective of strategies to improve tumor penetration of nanomedicines

Tumor penetration is important fo r effectively tumor targeting drug delivery.Recently,many researches are published to overcome the barriers that restrict tumor penetration and improve drug delivery efficiency.In the mini review,we first analyzed the barriers influence the tumor penetration,including tumor microenvironment barriers,nanoparticle properties,and interaction barriers between tumor and nanoparticles.To overcome the barrier,several strategies are developed,including modulating tumor microenvironment,changing particle size,transcytosis enabled tumor penetration,cell penetrating peptide modification and overcoming binding site barrier,which could effectively improve tumor penetration,and finally enhance tumor treatment outcome.     

NaN_3对玉米萌发过程中超弱光子辐射的影响

为了解读植物种子萌发过程中超弱光子辐射信息的生物学意义,采用呼吸抑制剂NaN3处理萌发玉米种子,跟踪测量和分析了玉米种子萌发过程中超弱光子辐射中自发光子辐射和外界光诱导的延迟光子辐射的变化规律,同时研究了萌发玉米种子鲜质量的变化.结果发现,NaN3同步抑制了萌发玉米自发光子辐射和鲜质量的增长,造成萌发玉米延迟光子辐射的初始光子数和延迟光子辐射积分强度大幅度降低,相干时间减小.机理分析表明,NaN3对呼吸代谢电子传递链的抑制造成的自由基反应减弱是萌发玉米自发光子辐射减小的原因,自发光子辐射强度可以作为玉米萌发状态的信号,延迟光子辐射动力学参数的大小可以表征萌发玉米呼吸代谢的强弱,相干时间是种子细胞组织序性的量度,通过对萌发种子超弱光子辐射的采集和分析可以实现对萌发种子细胞代谢和功能状态变化的灵敏和无损检测.