Drug development | EPFL Graph Search

Drug development is the process of bringing a new pharmaceutical drug to the market once a lead compound has been identified through the process of drug discovery. It includes preclinical research on microorganisms and animals, filing for regulatory status, such as via the United States Food and Drug Administration for an investigational new drug to initiate clinical trials on humans, and may include the step of obtaining regulatory approval with a new drug application to market the drug. The entire process – from concept through preclinical testing in the laboratory to clinical trial development, including Phase I–III trials – to approved vaccine or drug typically takes more than a decade. New chemical entity development Broadly, the process of drug development can be divided into preclinical and clinical work. Pre-clinical Pre-clinical development New chemical entities (NCEs, also known as new molecular entities or NMEs) are c

A Novel 3D hydrogel based microfluidic cell culture platform

Keshav Krishnamani

Breakthroughs in health care over the coming decades may well consist of cell based therapeutics, potentially allowing the repair and replacement of damaged tissues and organs. Recently developed induced pluripotency methods as well as advances in stem cell biology show hope of such a reality. But such prospects come with the need to have a robust understanding and control over cell development and differentiation processes. Cells in the body develop in tightly controlled and specialized micro-environments that provide many complex cues and interactions that guide cell fate by directing gene expression. But current cell culture techniques that are most widely used to study the cell outside the body have not significantly changed from when first started over a century ago, using simple containers and flasks with plastic surfaces. Many studies have shown that three-dimensions (3D) over conventional 2D cell culture alone, showed to have increased levels of cell organization, morphology and function. By combining novel biomaterials and microfabrication methods, this project aims to create a tool that allows the study of cells within a simplified 3D environment. With the potential to build up the physical and soluble complexity of this environment in a tailor made fashion, a "dissection" of the functions and influences of external factors may be understood. Such a tool can also be used for the development of cell based models, highly relevant for drug discovery application as well as potentially for the development of cell based therapeutics. We have developed a novel microfluidic 3D cell culture platform that allows controlled soluble factor perfusion in an enzymatically formed and cell responsive PEG-based hydrogel. Soft lithographic processes were used to mold microchannels on a layer of hydrogel. In a second step, a flat hydrogel layer is placed on top to enclose and form the microchannels . The system allows the control over soluble factor delivery and it is able to perform long-term cell culture and generate user controlled gradients of soluble factors. With continuous perfusion, metabolic waste is constantly removed and cells are supplied with fresh medium. The platform also can allow creation of tailor made environments building up complexity in a controlled fashion. Higher throughput is also achieved by arraying individual culture chambers. The device was applied towards the culture of mouse embryonic stem cells (mESC) in order to demonstrate their self-renewal capacity on the microfluidic platform. The effects of some cytokine factors were also studied. Meaningful readouts such as fluorescence are easily used for analysis and cells can possibly be extracted from the device for further downstream analysis and processing. Through this device we show that microfluidics technologies combined with biomaterials enables the creation of platforms that are biologically relevant for the study and understanding of cell processes from cancer to stem cell development, processes which are fundamentally regulated by interactions with the microenvironment. The platform developed may also be used to develop human tissue models perhaps more relevant than current animal based testing, providing new tools for drug development and also potentially new approaches for developing cell based therapeutics

2009

Caged luciferin probes for the bioluminescence imaging of nitroreductase and hydrogen sulfide in living animals

Anzhelika Vorobyeva

Molecular imaging advances our understanding of cellular and molecular functions within complex biological systems. The development of novel imaging probes that can be applied to answer fundamental biological questions, diagnose and monitor disease progression and the efficacy of therapy in vivo is essential to the field of molecular imaging. Bioluminescence imaging is a powerful technique that allows to study and follow biological processes of interest noninvasively in real-time in living animals. Activatable bioluminescent probes can be designed according to the target of interest and can provide imaging signal in response to the specific stimuli. A strategy called "caged luciferin" can be used to design new bioluminescent probes for imaging of enzymatic activity, the presence of small molecules or metabolite uptake in vivo. In Chapter 1 we present an overview of bioluminescence imaging, with a focus on firefly luciferase-luciferin system. The caged luciferin approach is discussed and examples of existing caged luciferin probes are presented. In Chapter 2 we describe the development of a bioluminescent probe for imaging of bacterial nitroreductase activity and show the potential for its application in different areas of research. Bacterial nitroreductases have been widely utilized in the gene-directed enzyme prodrug therapy (GDEPT) approach for cancer therapy that reached clinical trials. However, both preclinical and clinical development of NTR-based GDEPT systems has been hampered by the lack of imaging tools that allow in vivo evaluation of transgene expression. We developed the NTR caged luciferin (NCL) probe and demonstrated its application for sensitive bioluminescence imaging of NTR in vitro, in bacteria and cancer cells, as well as in vivo in mouse models of bacterial infection and NTR-expressing tumor xenografts. We anticipate that this probe would significantly accelerate the development of cancer therapy approaches based on GDEPT and other fields where evaluation of NTR expression is important. In Chapter 3 we describe the development of a bioluminescent probe for imaging of hydrogen sulfide (H2S) using the caged luciferin approach. The objective of the research was to develop a probe that can detect endogenously produced H2S noninvasively in real-time in living animals. We present a series of caged luciferin probes that were evaluated on their ability to rapidly and selectively detect H2S in in vitro assays, in cells and in bacterial culture. The two selected probes were applied for imaging of exogenous H2S in the gastrointestinal tract in living mice. We anticipate further applications of the best performing probe (Az-CL) for imaging of H2S production by gut microbiota in mice. In Chapter 4 we present the overall conclusion followed by the outlook and future perspectives.

EPFL2016

Sirtuin 2 Deficiency Increases Bacterial Phagocytosis by Macrophages and Protects from Chronic Staphylococcal Infection

Johan Auwerx, Tytti Heinonen, Marc Pfefferlé

Sirtuin 2 (SIRT2) is one of the seven members of the family of NAD(+)-dependent histone deacetylases. Sirtuins target histones and non-histone proteins according to their subcellular localization, influencing various biological processes. SIRT2 resides mainly in the cytoplasm and regulates cytoskeleton dynamics, cell cycle, and metabolic pathways. As such, SIRT2 has been implicated in the pathogenesis of neurodegenerative, metabolic, oncologic, and chronic inflammatory disorders. This motivated the development of SIRT2-directed therapies for clinical purposes. However, the impact of SIRT2 on antimicrobial host defense is largely unknown. Here, we address this question using SIRT2 knockout mice. We show that SIRT2 is the most highly expressed sirtuin in myeloid cells, especially macrophages. SIRT2 deficiency does not affect immune cell development and marginally impacts on intracellular signaling and cytokine production by splenocytes and macrophages. However, SIRT2 deficiency enhances bacterial phagocytosis by macrophages. In line with these observations, in preclinical models, SIRT2 deficiency increases survival of mice with chronic staphylococcal infection, while having no effect on the course of toxic shock syndrome toxin-1, LPS or TNF-induced shock, fulminant Escherichia coli peritonitis, sub-lethal Klebsiella pneumoniae pneumonia, and chronic candidiasis. Altogether, these data support the safety profile of SIRT2 inhibitors under clinical development in terms of susceptibility to infections.

Frontiers Media Sa2017