Smaller, simpler biotherapeutics pave the way for new production methods
Mammalian expression systems have driven the rise of biotherapeutics. Their ability to introduce proper protein folding, post-translational modifications, and product assembly means that they are currently used to produce almost all therapeutic antibodies to ensure correct structure and minimize the risk of immunogenicity. But the advent of smaller, simpler biotherapeutics means that prokaryote expression systems such Escherichia coli (E. coli) are playing a new role in antibody therapy. These bacteria can deliver high expression levels, with simpler bioprocessing at a lower cost together with an extensive molecular toolbox based on well-characterized genetics. This development is increasing the need for sensitive methods to monitor bioprocess development and manufacturing based on E. coli-based expression systems, including the sensitive analysis of host cell proteins.
Obesity has become a devastating pandemic, with 108 million obese children and 604 million obese adults worldwide in 2015, and the problem is increasing (1). The result is an escalation in serious conditions such as type 2 diabetes mellitus (T2DM), cardiovascular disease, hypertension, dyslipidemia and several cancer forms, mainly gastrointestinal. Obesity is very difficult to treat through life style changes and surgery has become the most effective and long-lasting route to sustained weight loss, although it is only available to a small subset of individuals, and is both costly and risky. The search for more widely applicable treatment has driven the development of peptide-based pharmaceuticals that can meet key challenges of obesity, including control over satiety, blood sugar and LDL cholesterol levels. 
