TY  - JOUR
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Krischer, M.
A1  - Wenzel, L.
A1  - Leinhos, Marcel
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor
JF  - Procedia Engineering
N2  - A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers.
KW  - Field-effect sensor
KW  - enzymatic (bio)degradation
KW  - poly(d, l-lactic acid)
KW  - in-situ monitoring
KW  - impedance spectroscopy
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.689
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 1314
EP  - 1317
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Takenaga, Shoko
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Öhlschläger, Peter
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis–Menten-like kinetics for cell culturing
JF  - Physica status solidi A : Applications and materials science
N2  - The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17–200 mM) follows a Michaelis–Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330464
SN  - 1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1410
EP  - 1415
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
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  -