Electrophoresis of pharmaceutical proteins:Status quo

Monitorization of α1-Acid Glycoprotein Deglycosylation Using SU-8 Microchips Electrophoresis with LIF Detection

In the last few years, biopharmaceuticals-therapeutic drugs which are generally obtained by using molecular biology techniques-have become a major growing sector in pharmaceutical industry. A large part of these biopharmaceuticals are therapeutic glycoproteins. The production of these drugs and their purification process are implying the development of efficient analytical methods, which allow quick and reliable control of the manufacturing process and ensuring the regulatory compliance about the quality of these drugs. Capillary gel electrophoresis (CGE) in the presence of sodium dodecyl sulfate (SDS) is becoming a method of choice in the quality control of these biopharmaceuticals. On the other hand, CGE can be improved if analyses are carried out in microchip format.This chapter reports a detailed microchips gel electrophoresis (MGE) method to separate glycosylated and deglycosylated forms of α1-acid glycoprotein (AGP) labeled with Chromeo P540, using SU-8 microchips and laser induced fluorescence detection. Due to the analogy between AGP and some therapeutic glycoproteins, we have selected AGP as a model system to illustrate the potential of MGE in the analysis of this type of biopharmaceutical compounds.

Recent advances in the analysis of therapeutic proteins by capillary and microchip electrophoresis

The development of therapeutic proteins and peptides is an expensive and time-intensive process. Biologics, which have become a multi-billion dollar industry, are chemically complex products that require constant observation during each stage of development and production. Post-translational modifications along with chemical and physical degradation from oxidation, deamidation, and aggregation, lead to high levels of heterogeneity that affect drug quality and efficacy. The various separation modes of capillary electrophoresis (CE) are commonly utilized to perform quality control and assess protein heterogeneity. This review attempts to highlight the most recent developments and applications of CE separation techniques for the characterization of protein and peptide therapeutics by focusing on papers accepted for publication in the in the two-year period between January 2012 and December 2013. The separation principles and technological advances of CE, capillary gel electrophoresis, capillary isoelectric focusing, capillary electrochromatography and CE-mass spectrometry are discussed, along with exciting new applications of these techniques to relevant pharmaceutical issues. Also included is a small selection of papers on microchip electrophoresis to show the direction this field is moving with regards to the development of inexpensive and portable analysis systems for on-site, high-throughput analysis.

Development of an SDS-gel electrophoresis method on SU-8 microchips for protein separation with LIF detection: Application to the analysis of whey proteins

This work describes the development of an SDS-gel electrophoresis method for the analysis of major whey proteins (α-lactalbumin, β-lactoglobulin, and BSA) carried out in SU-8 microchips. The method uses a low-viscosity solution of dextran as a sieving polymer. A commercial coating agent (EOTrol LN) was added to the separation buffer to control the EOF of the chips. The potential of this coating agent to prevent protein adsorption on the walls of the SU-8 channels was also evaluated. Additionally, the fluorescence background of the SU-8 material was studied to improve the sensitivity of the method. By selecting an excitation wavelength of 532 nm at which the background fluorescence remains low and by replacing the mercury arc lamp by a laser in the detection system, an LOD in the nanomolar range was achieved for proteins derivatized with the fluorogenic reagent Chromeo P540. Finally, the method was applied to the analysis of milk samples, demonstrating the potential of SU-8 microchips for the analysis of proteins in complex food samples.

Identifying analytics for high throughput bioprocess development studies

In recent years, high throughput screening (HTS) studies have been increasingly employed as an integral element of bioprocess development activities. These studies are often limited by an analytical bottleneck; they generate multiple samples for analysis and the available analytical methods cannot always cope with the added analytical burden. A potential solution to this challenge is offered by the deployment of appropriate analytics. This article outlines features of analytical methods that affect their fit to high throughput (HT) applications. These are discussed for a range of analytics frequently used in bioprocess development studies of monoclonal antibodies. It then outlines how these features need to be considered in order to classify analytical methods in terms of their particular application in high throughput scenarios.