Current Pharmaceutical Biotechnology - Volume 17, Issue 9, 2016

During drug development, large libraries of new chemical entities (NCEs) are generated and undergo in vitro screens of metabolism and cytotoxicity. These screens are heavily relied upon to select lead compounds with the highest chance of success in pre-clinical studies and clinical trials, but suffer from limited in vivo predictive power despite using human liver-derived components. There is a need for new assays that utilize smaller reagent volumes to reduce the cost of these high-throughput screens; better mimic the liver environment; and ultimately account for toxicities in other major organ systems. Microfabricated devices, in their current state, integrate multiple reaction steps in a single device, decreasing the cost of a single metabolism or cytotoxicity screen by lowering the reagent consumption and increasing throughput. The incorporation of three-dimensional co-cultures in these devices promise increased accuracy of in vitro screens, because cellular phenotype and response of hepatocytes in these cultures are more representative of the liver. In this review, we focus on microfabricated devices developed over the past decade and highlight technologies that we believe have the potential of reaching shorter- and longer-term goals of reducing the cost of bringing new drugs to market and revolutionizing the discovery stage of the drug development pipeline.

Therapeutic drugs administered systematically are evenly distributed to the whole body through blood circulation and have to cross many biological barriers before reaching the pathological site. Conventional drug delivery may make drugs inactive or reduce their potency as they may be hydrolyzed or degraded enzymatically and are rapidly excreted through the urinary system resulting in suboptimal concentration of drugs at the desired site. Controlled drug delivery aims to localize the pharmacological activity of the drug to the desired site at desired release rates. The advances made by micro/nanofluidic technologies have provided new opportunities for better-controlled drug delivery. Various components of a drug delivery system can be integrated within a single tiny micro/nanofluidic chip. This article reviews recent advances of controlled drug delivery made by microfluidic/nanofluidic technologies. We first discuss microreservoir-based drug delivery systems. Then we highlight different kinds of microneedles used for controlled drug delivery, followed with a brief discussion about the current limitations and the future prospects of controlled drug delivery systems.

Therapeutic monoclonal antibodies (mAbs) have made a tremendous impact in treating patients with various diseases. MAbs are designed to specifically target a cell and illicit a response from the immune system to destroy the cell. As originator mAb drug patents are coming to an end, generic pharmaceutical companies are poised to replicate and produce so-called biosimilar drugs. MAbs are significantly more complicated than small drugs to analyze and produce. The mAb proteoform and glycoform must be as similar to the original drug as possible to be a viable replacement. The mAb proteoform is well characterized but can be altered through various undesirable reactions such as deamidation. The mAb glycoform is harder to replicate as the glycan formation is a complicated templateless one; it is proving difficult for the originator companies to produce a homogenous population of mAbs from batch to batch. Severe side-effects have occurred in patients taking mAbs with immunogenic glycans, highlighting the importance of quality control mechanisms. The complex nature of mAbs requires sensitive and robust tools amenable to the highthroughput analysis required by a manufacturing setting. Miniaturized analytical platforms for complex biosimilar analysis are still in their infancy but have shown great promise for sample preparation. Capillary electrophoresis-laser induced fluorescence remains a powerful and fast technique for routine glycan analysis. Mass spectrometry is the method of choice for the analysis of mAb proteoforms and is emerging as a powerful tool for glycoform analysis.

Cancer, as the most serious threat to human health, poses millions of deaths in the world each year. In vitro cancer cell and biomarker detection is of great importance for early cancer diagnosis and therapy, which needs highly sensitive, selective and quantitative diagnosis platforms. Threedimensional paper-based electrochemical devices (3D-PEDs) have attracted considerable interest in biomedical fields in recent years based on their simplicity, low cost, portability, high sensitivity and selectivity. Recently, since 3D-PEDs can particularly provide in vitro 3D structures to mimic the native 3D cell microenvironment, they have been used to detect cancer cells and monitor their responses to anticancer drug treatment in terms of cancer cell concentration, cancer cell apoptosis and cancer biomarkers. This review discusses the recent development of 3D-PEDs and their applications in detection of cancer cells and anticancer drug screening.

The research of circulating tumor cells (CTCs) has drawn much attention in recent years. It is because of the potential values of CTCs in early diagnosis of cancer, management of clinical treatment, exploration of metastatic mechanism, and development of personalized medicine. However, isolating CTCs has been technically challenging due to their rare numbers in blood. Recently, a variety of microfluidic devices have been developed for CTC isolation, and these devices can realize high capture efficiency and high purity. While enumeration of CTCs has been achieved, further cellular and DNA analysis on the captured CTCs are less reported. In this article, we review recent reports in microfluidic methods for isolation of CTCs and subsequent cellular analysis on them.

Drug discovery is a long and expensive process, which usually takes 12-15 years and could cost up to ~$1 billion. Conventional drug discovery process starts with high throughput screening and selection of drug candidates that bind to specific target associated with a disease condition. However, this process does not consider whether the chosen candidate is optimal not only for binding but also for ease of administration, distribution in the body, effect of metabolism and associated toxicity if any. A holistic approach, using model organisms early in the drug discovery process to select drug candidates that are optimal not only in binding but also suitable for administration, distribution and are not toxic is now considered as a viable way for lowering the cost and time associated with the drug discovery process. However, the conventional drug discovery assays using Drosophila are manual and required skill operator, which makes them expensive and not suitable for high-throughput screening. Recently, microfluidics has been used to automate many of the operations (e.g. sorting, positioning, drug delivery) associated with the Drosophila drug discovery assays and thereby increase their throughput. This review highlights recent microfluidic devices that have been developed for Drosophila assays with primary application towards drug discovery for human diseases. The microfluidic devices that have been reviewed in this paper are categorized based on the stage of the Drosophila that have been used. In each category, the microfluidic technologies behind each device are described and their potential biological applications are discussed.

This work aimed to characterize and evaluate the antihypertensive effect of the (-)-β-pinene/β-cyclodextrin (βP/β-CD) complex. The complex was prepared through physical mixture and slurry complexation methods and was analyzed through differential scanning calorimetry, thermogravimetry/derivative thermogravimetry, fourier transform infrared spectroscopy, diffraction X-ray, docking and scanning electron microscopy. Normotensive or L-NAME-induced hypertensive rats were used in pharmacological experiments. Mean arterial pressure (MAP) was determined with direct blood pressure measurements from the abdominal aorta. The drugs were orally administrated and their effects were recorded during 48 hours. Vascular effects of βP were evaluated in isolated ring of mesenteric artery. The physicochemical characterization showed βP/β-CD complex formation. In hypertensive rats (MAP = 156±16 mmHg), the complex, but not βP alone, promoted hypotension at 36 and 48 hours after administration (MAP = 124±3 and 110±5 mmHg, respectively). In arterial rings, βP vasorelaxed rings precontracted with phenylephrine (Emax = 105±6%), which was not changed after the removal of the vascular endothelium (Emax = 108±4%), after the pre-contraction with KCl 80 mM (Emax = 107±8%) or S(-)-BayK8644 (Emax = 107±5%), or after incubation with TEA (Emax = 113±4%). Finally, βP inhibited CaCl2- and sodium-orthovanadate-induced contractions. In conclusion, the slurry complexation method was the best among them. Pharmacological results demonstrated that the complex promoted antihypertensive effect. Furthermore, βP induced endothelium- independent vasorelaxation possibly caused by the inhibition of the Ca2+ influx through L-type Ca2+ channel associated to a decrease in calcium sensitivity.