TY  - JOUR
A1  - Winckler, Silvia
A1  - Krueger, Rolf
A1  - Schnitzler, Thomas
A1  - Zang, Werner
A1  - Fischer, Rainer
A1  - Biselli, Manfred
T1  - A sensitive monitoring system for mammalian cell cultivation processes: a PAT approach
JF  - Bioprocess and biosystems engineering
N2  - Biopharmaceuticals such as antibodies are produced in cultivated mammalian cells, which must be monitored to comply with good manufacturing practice. We, therefore, developed a fully automated system comprising a specific exhaust gas analyzer, inline analytics and a corresponding algorithm to precisely determine the oxygen uptake rate, carbon dioxide evolution rate, carbon dioxide transfer rate, transfer quotient and respiratory quotient without interrupting the ongoing cultivation, in order to assess its reproducibility. The system was verified using chemical simulation experiments and was able to measure the respiratory activity of hybridoma cells and DG44 cells (derived from Chinese hamster ovary cells) with satisfactory results at a minimum viable cell density of ~2.0 × 10⁵ cells ml⁻¹. The system was suitable for both batch and fed-batch cultivations in bubble-aerated and membrane-aerated reactors, with and without the control of pH and dissolved oxygen.
Y1  - 2014
U6  - http://dx.doi.org/10.1007/s00449-013-1062-8
SN  - 1615-7591 (Print) 1615-7605 (Online)
VL  - 37
IS  - 5
SP  - 901
EP  - 912
PB  - Springer
CY  - Berlin, Heidelberg
ER  - 
TY  - JOUR
A1  - Jens, Otto
A1  - Kaldenhoff, E.
A1  - Kirschner-Hermanns, R.
A1  - Mühl, Thomas
A1  - Klinge, Uwe
T1  - Elongation of textile pelvic floor implants under load is related to complete loss of effective porosity, thereby favoring incorporation in scar plates
JF  - Journal of biomedical materials research. Part A
N2  - Use of textile structures for reinforcement of pelvic floor structures has to consider mechanical forces to the implant, which are quite different to the tension free conditions of the abdominal wall. Thus, biomechanical analysis of textile devices has to include the impact of strain on stretchability and effective porosity. Prolift® and Prolift + M®, developed for tension free conditions, were tested by measuring stretchability and effective porosity applying mechanical strain. For comparison, we used Dynamesh-PR4®, which was designed for pelvic floor repair to withstand mechanical strain. Prolift® at rest showed moderate porosity with little stretchability but complete loss of effective porosity at strain of 4.9 N/cm. Prolift + M® revealed an increased porosity at rest, but at strain showed high stretchability, with subsequent loss of effective porosity at strain of 2.5 N/cm. Dynamesh PR4® preserved its high porosity even under strain, but as consequence of limited stretchability. Though in tension free conditions Prolift® and Prolift + M® can be considered as large pore class I meshes, application of mechanical strain rapidly lead to collapse of pores. The loss of porosity at mechanical stress can be prevented by constructions with high structural stability. Assessment of porosity under strain was found helpful to define requirements for pelvic floor devices. Clinical studies have to prove whether devices with high porosity as well as high structural stability can improve the patients' outcome.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/jbm.a.34767
SN  - 1552-4965
VL  - 102
IS  - 4
SP  - 1079
EP  - 1084
PB  - Wiley
CY  - New York
ER  -