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Drug plasma protein binding remains highly relevant to research and drug development, making the assessment and profiling of compound affinity to plasma proteins essential to drug discovery efforts. Although there are a number of fully-characterized methods, they lack the throughput to handle large numbers of compounds. As the evaluation of adsorption, distribution, metabolism, and excretion is addressed earlier in the drug development timeline, the need for higher-throughput methods has grown. Areas Covered: This review will highlight recent developments on methods for profiling drug plasma binding, with an emphasis on fluorescent probes and emerging high-throughput methodologies. Expert Opinion: There have been a number of high-throughput assays developed in recent years to meet the scaled up demands for compound profiling. Ultimately, the selection of assay technology relies on a number of factors, such as capabilities of the laboratory and the breadth and amount of data required. Fluorescent probe displacement assays are highly flexible and amenable to high-throughput screening, easily scaling up to handle large compound libraries. Recent developments in fluorescence technologies, such as homogenous time-resolved fluorescence and probes utilizing the aggregation-induced emission effect, have improved the sensitivity of these assays. Other technologies, such as microscale thermophoresis and quantitative structure-activity relationship modeling, are gaining popularity as alternative techniques for drug plasma protein binding characterization.

Much has been presented and debated on the topic of drug abuse and its multidimensional nature, including the role of society and its customs and laws, economical factors, and the magnitude and nature of the burden. Given the complex nature of the receptors and pathways implicated in regulation of the cognitive and behavioral processes associated with addiction, a large number of molecular targets have been interrogated during recent years to discover starting points for development of small-molecule interventions.This review describes recent developments in the field of early drug discovery for drug abuse interventions with an emphasis on the advances published during the 2012 - 2014 period.Technologically, the processes/platforms utilized in drug abuse drug discovery are nearly identical to those used in the other disease areas. A key complicating factor in drug abuse research is the enormous biological complexity surrounding the brain processes involved and the associated difficulty in finding 'good' targets and achieving exquisite selectivity of treatment agents. While tremendous progress has been made during recent years to use the power of high-throughput technologies to discover proof-of-principle molecules for many new targets, next-generation models will be especially important in this field. Examples include: seeking advantageous drug-drug combinations, the use of automated whole-animal behavioral screening systems, advancing our understanding of the role of epigenetics in drug addiction and the employment of organoid-level 3D test platforms (also referred to as tissue-chip or organs-on-chip).

Despite tremendous advances in the application of biophysical methods in drug discovery, the preponderance of instruments and techniques still require sophisticated analyses by dedicated personnel and/or large amounts of frequently hard-to-produce proteins. A technique which carries the promise of simplicity and relatively low protein consumption is the differential scanning fluorometry (DSF). This technique monitors protein through the use of environmentally sensitive fluorescent dye, in a temperature-ramp regime by observing the gradual exposure to the solvent of otherwise buried hydrophobic faces of protein domains.This review describes recent developments in the field of DSF. This article pays a particular emphasis on the advances published during the 2010 - 2013 period.There has been a significant diversification of DSF applications beyond initial small molecule discovery into areas such as protein therapeutic development, formulation studies and various mechanistic investigations. This serves as a further indication of the broad penetration of the technique. In the small molecule arena, DSF has expanded toward sophisticated co-dependency MOA tests, demonstrating the wealth of information which the technique can provide. Importantly, the first public deposition of a large screening dataset may enable the use of thermal stabilization data in refining in silico models for small molecule binding.

Since the first application of antibiotics to treat bacterial infections, the development and spread of resistance has been a persistent threat. An ever evolving pipeline of next-generation therapeutics is required for modern medicine to remain one step ahead of pathogens.This review describes recent efforts to develop drugs that interrupt the assimilation of iron by bacteria: a process that is vital to cellular homeostasis and is not currently targeted by antibiotics used in the clinic. This review also covers the mechanisms by which bacteria acquire iron for their environment, and details efforts to intervene in these processes, using small molecule inhibitors that target key steps in these pathways, with a special emphasis on recent advances published during the 2010 - 2012 period.For decades, the routes used by bacteria to assimilate iron from host and environmental settings have been the subject of intense study. While numerous investigations have identified inhibitors of these pathways, many have stopped short of translating the in vitro results to in vivo proof of concept experiments. The extension of preliminary findings in this manner will significantly increase the impact of the field.

Fluorescence polarization (FP) is a homogeneous method that allows rapid and quantitative analysis of diverse molecular interactions and enzyme activities. This technique has been widely utilized in clinical and biomedical settings, including the diagnosis of certain diseases and monitoring therapeutic drug levels in body fluids. Recent developments in the field have been symbolized by the facile adoption of FP in high-throughput screening and small molecule drug discovery of an increasing range of target classes.The article provides a brief overview of the theoretical foundation of FP, followed by updates on recent advancements in its application for various drug target classes, including GPCRs, enzymes and protein-protein interactions. The strengths and weaknesses of this method, practical considerations in assay design, novel applications and future directions are also discussed.The reader is informed of the most recent advancements and future directions of FP application to small molecule screening.In addition to its continued utilization in high-throughput screening, FP has expanded into new disease and target areas and has been marked by increased use of labeled small molecule ligands for receptor-binding studies.

High-resolution microscopy using fluorescent probes is a powerful tool to investigate individual cell structure and function, cell subpopulations and mechanisms underlying cellular responses to drugs. Additionally, responses to drugs more closely resemble those seen in vivo when cells are physically connected in three-dimensional (3D) systems (either 3D cell cultures or whole organisms), as opposed to traditional monolayer cultures. Combined, the use of imaging-based 3D models in the early stages of drug development has the potential to generate biologically relevant data that will increase the likelihood of success for drug candidates in human studies.The authors discuss current methods for the culturing of cells in 3D as well as approaches for the imaging of whole-animal models and 3D cultures that are amenable to high-throughput settings and could be implemented to support drug discovery campaigns. Furthermore, they provide critical considerations when discussing imaging these 3D systems for high-throughput chemical screenings.Despite widespread understanding of the limitations imposed by the two-dimensional versus the 3D cellular paradigm, imaging-based drug screening of 3D cellular models is still limited, with only a few screens found in the literature. Image acquisition in high throughput, accurate interpretation of fluorescent signal, and uptake of staining reagents can be challenging, as the samples are in essence large aggregates of cells. The authors recognize these shortcomings that need to be overcome before the field can accelerate the utilization of these technologies in large-scale chemical screens.