Economics and ecology: Modelling of continuous primary recovery and capture scenarios for recombinant antibody production.

With the maturation of antibody production technologies, both economic optimization and ecological aspects have become important. Continuous downstream processing is a way to reduce the environmental footprint and improve process economics. We compared different primary recovery, capture, and fermentation methods for two output-based antibody production scales: 50 kg/year and 1000 kg/year. In addition, a fixed fermentation volume case of 1000 L was analysed in terms of total cost of goods and process mass intensity as a measure of the environmental footprint. In our scenario, a significant amount of water can be saved in downstream processing when single use equipment is utilized. The overall economic and ecological impact is governed by the product titre in our perfusion (1 g/L) and fed-batch (4 g/L). A low titre in fermentation with similar downstream purification leads to higher process mass intensity and cost of goods due to the higher media demand upstream. The economic perspective for continuous integrated biomanufacturing is very attractive, but environmental consequences should not be neglected. Here, we have shown that perfusion has a higher environmental footprint in the form of water consumption compared to fed-batch. As general guidance to improve process economics, we recommend reducing water consumption.

Biochemical and biological evaluation of novel potent coumarin inhibitor of 17ß-HSD type 1.

Human 17ß-hydroxysteroid dehydrogenase (17ß-HSD) type 1 is an enzyme that acts at the pre-receptor level. It catalyzes the NADPH-dependent reduction of the weak estrogen estrone into the most potent estrogen 17ß-estradiol, which exerts proliferative effects via estrogen receptors. Overexpression of 17ß-HSD type 1 in estrogen-responsive tissues is related to the development of hormone-dependent diseases, such as breast cancer and endometriosis. 17ß-HSD type 1 thus represents an attractive target for development of new drugs. Recently, we discovered that substituted coumarin derivatives potently and selectively inhibit 17ß-HSD type 1. In the present study, we have performed additional biochemical and biological evaluation of the most promising coumarin derivative. First, we used an efficient method for isolation and purification of the active, soluble recombinant human 17ß-HSD type 1 from Escherichia coli. This 17ß-HSD type 1 showed a specific activity of 0.64±0.08 µmol min(-1) mg(-1) for estrone reduction in the presence of NADPH at pH 6.5, and a K(m) of 62 nM for estrone. Next, we evaluated the best of the coumarin-derivative inhibitors, showing its reversible and competitive inhibition of 17ß-HSD type 1 reductive activity with a K(i) of 53 nM. We confirmed that this coumarin inhibitor acts not only in a cell-free assay, but also decreases endogenous 17ß-HSD type 1 activity in human T-47D breast cancer cells. This inhibitor also reduced estrone dependent growth of T-47D cells after 48 h of incubation.