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Young AT, Rivera KR, Erb PD, Daniele MA. Monitoring of Microphysiological Systems: Integrating Sensors and Real-Time Data Analysis toward Autonomous Decision-Making. ACS Sens 2019; 4:1454-1464. [PMID: 30964652 DOI: 10.1021/acssensors.8b01549] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Microphysiological systems replicate human organ function and are promising technologies for discovery of translatable biomarkers, pharmaceuticals, and regenerative therapies. Because microphysiological systems require complex microscale anatomical structures and heterogeneous cell populations, a major challenge remains to manufacture and operate these products with reproducible and standardized function. In this Perspective, three stages of microphysiological system monitoring, including process, development, and function, are assessed. The unique features and remaining technical challenges for the required sensors are discussed. Monitoring of microphysiological systems requires nondestructive, continuous biosensors and imaging techniques. With such tools, the extent of cellular and tissue development, as well as function, can be autonomously determined and optimized by correlating physical and chemical sensor outputs with markers of physiological performance. Ultimately, data fusion and analyses across process, development, and function monitors can be implemented to adopt microphysiological systems for broad research and commercial applications.
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Affiliation(s)
- Ashlyn T. Young
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina, Chapel Hill, 911 Oval Drive, Raleigh, North Carolina 27695, United States
| | - Kristina R. Rivera
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina, Chapel Hill, 911 Oval Drive, Raleigh, North Carolina 27695, United States
| | - Patrick D. Erb
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina, Chapel Hill, 911 Oval Drive, Raleigh, North Carolina 27695, United States
| | - Michael A. Daniele
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina, Chapel Hill, 911 Oval Drive, Raleigh, North Carolina 27695, United States
- Department of Electrical & Computer Engineering, North Carolina State University, 890 Oval Drive, Raleigh, North Carolina 27695, United States
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Costa AR, Rodrigues ME, Henriques M, Oliveira R, Azeredo J. Feed optimization in fed-batch culture. Methods Mol Biol 2014; 1104:105-116. [PMID: 24297412 DOI: 10.1007/978-1-62703-733-4_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fed-batch processes are a current preference for the production of recombinant proteins in mammalian cells. The use of nutrient feeding prevents the depletion of important medium components and results in improved culture longevity and high cell and product yields. To take maximum advantage of these effects, it is important to optimize the fed-batch process for each application. In this chapter, a simple strategy for fed-batch optimization is described, consisting of the development of a feed medium based on spent media analysis and the establishment of a feeding strategy that consists of adding variable volumes of feed media at specific intervals, after off-line measurement of the concentration of a reference nutrient.
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Affiliation(s)
- Ana Rita Costa
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Braga, Portugal
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Karra S, Sager B, Karim MN. Multi-Scale Modeling of Heterogeneities in Mammalian Cell Culture Processes. Ind Eng Chem Res 2010. [DOI: 10.1021/ie100125a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Srinivas Karra
- Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409
| | - Brian Sager
- Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409
| | - M. Nazmul Karim
- Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409
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Senger RS, Karim MN. Optimization of fed-batch parameters and harvest time of CHO cell cultures for a glycosylated product with multiple mechanisms of inactivation. Biotechnol Bioeng 2007; 98:378-90. [PMID: 17385745 DOI: 10.1002/bit.21428] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Optimization of fed-batch feeding parameters was explored for a system with multiple mechanisms of product inactivation. In particular, two separate mechanisms of inactivation were identified for the recombinant tissue-type activator (r-tPA) protein. Dynamic inactivation models were written to describe particular r-tPA glycoform inactivation in the presence and absence of free-glucose. A glucose-independent inactivation mechanism was identified, and inactivation rate constants were found dependent upon the presence of glycosylation of r-tPA at N184. Inactivation rate constants of the glucose-dependent mechanism were not affected by glycosylation at N184. Fed-batch optimization was performed for r-tPA production by CHO cell culture in a stirred-tank reactor with glucose, glutamine and asparagine feed. Feeding profiles in which culture supernatant concentrations of free-glucose and amino acids (combined glutamine and asparagine) were used as control variables, were evaluated for a wide variety of set points. Simulation results for a controlled feeding strategy yielded an optimum at set points of 1.51 g L(-1) glucose and 1.18 g L(-1) of amino acids. Optimization was also performed in absence of metabolite control using fixed feed-flow rates initiate during the exponential growth phase. Fixed feed-flow results displayed a family of optimum solutions along a mass flow rate ratio of 3.15 of glucose to amino acids. Comparison of the two feeding strategies showed a slight advantage of rapid feeding at a fixed flow rate as opposed to metabolite control for a product with multiple mechanisms of inactivation.
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Affiliation(s)
- Ryan S Senger
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA
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Senger RS, Karim MN. Effect of shear stress on intrinsic CHO culture state and glycosylation of recombinant tissue-type plasminogen activator protein. Biotechnol Prog 2003; 19:1199-209. [PMID: 12892482 DOI: 10.1021/bp025715f] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Shear stress in suspension culture was investigated as a possible manipulative parameter for the control of glycosylation of the recombinant tissue-type plasminogen activator protein (r-tPA) produced by recombinant Chinese hamster ovary (CHO) cell culture, grown in protein-free media. Resulting fractions of partially glycosylated, Type II, and fully glycosylated, Type I, r-tPA protein were monitored as a direct function of the shear characteristics of the culture environment. The shear-induced response of CHO culture to levels of low shear stress, where exponential growth was not obtained, and to higher levels of shear stress, which resulted in extensive cell death, were examined through manipulation of the bioreactor stirring velocity. Both apparent and intrinsic cell growth, metabolite consumption, byproduct and r-tPA production, and r-tPA glycosylation, from a variable site-occupancy standpoint, were monitored throughout. Kinetic analyses revealed a shear-stress-induced alteration of cellular homeostasis resulting in a nonlinear dependency of metabolic yield coefficients and an intrinsic cell lysis kinetic constant on shear stress. Damaging levels of shear stress were used to investigate the shear dependence of cell death and lysis, as well as the effects on the intrinsic growth rate of the culture. Kinetic models were also developed on the basis of the intrinsic state of the culture and compared to traditional models. Total r-tPA production was maximized under moderate shear conditions, as was the viable CHO cell density of the culture. However, Type II r-tPA production and the fraction of Type II glycoform production ratio was maximized under damaging levels of shear stress. Analyses of biomass production yield coefficients coupled with a plug-flow reactor model of glycan addition in the endoplasmic reticulum (ER) were used to propose an overall mechanism of decreased r-tPA protein site-occupancy glycosylation with increasing shear stress. Decreased residence time of r-tPA in the ER as a result of increased protein synthesis related to shear protection mechanisms is proposed to limit contact of site Asn184 with the membrane-bound oligosaccharyltransferase enzyme in the ER.
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Affiliation(s)
- Ryan S Senger
- Department of Chemical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
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Simon L, Karim MN. Control of starvation-induced apoptosis in Chinese hamster ovary cell cultures. Biotechnol Bioeng 2002; 78:645-57. [PMID: 11992530 DOI: 10.1002/bit.10250] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The application of the unscented Kalman filter to control starvation-induced programmed cell death-apoptosis-in Chinese hamster ovary cells was investigated. Neural network-based sensitivity analysis identified glutamine and asparagine as two major amino acids that play a key role in the suppression of apoptosis. Dynamic equations that accounted for the dependence of apoptotic cells on the concentrations of viable cells, glutamine, and asparagine were derived. These state equations were highly nonlinear and included nine state variables. An oxygen mass balance was written in the liquid phase. It served as the output equation for the unscented Kalman filter. Using the oxygen uptake rate as the observer, it was possible to estimate the states. A model predictive controller was then implemented once the apoptotic cells in the bioreactor approached a concentration of 1.5 x 10(4) cells/mL, taking into account the operating range of the flow cytometer and measurement error. The manipulated variables were the flow rates of glucose, glutamine, and asparagine. Simulation results showed that the controller was able to keep the apoptotic cells at a concentration of 1.5 x 10(4) cells/mL.
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Affiliation(s)
- Laurent Simon
- Chemical Engineering Department, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
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Dallet P, Labat L, Kummer E, Dubost JP. Determination of urea, allantoin and lysine pyroglutamate in cosmetic samples by hydrophilic interaction chromatography. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 742:447-52. [PMID: 10901151 DOI: 10.1016/s0378-4347(00)00196-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A new HPLC method using a Polyhydroxyethyl A column involving hydrophilic interaction chromatography (HILIC) is described for the simultaneous determination of urea, allantoin and lysine pyroglutamate in a cosmetic cream. Validation of the method was accomplished with respect to linearity, repeatability and limits of detection/quantification. Compound recoveries approach 100% with acceptable RSD values. The method is very simple since no derivatisation is necessary. Furthermore, it allows the rapid and direct chromatographic analysis of urea and hence could provide an alternative to other methods used to determine this compound in biological or cosmetic samples.
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Affiliation(s)
- P Dallet
- Laboratoire de Chimie analytique, UFR Pharmacie, Université Victor Segalen, Bordeaux, France.
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Ducommun P, Ruffieux P, Furter M, Marison I, von Stockar U. A new method for on-line measurement of the volumetric oxygen uptake rate in membrane aerated animal cell cultures. J Biotechnol 2000; 78:139-47. [PMID: 10725537 DOI: 10.1016/s0168-1656(99)00237-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Oxygen is a key substrate in animal cell metabolism and its consumption is thus a parameter of great interest for bioprocess monitoring and control. A system for measuring it based on an oxygen balance on the liquid phase was developed. The use of a gas-permeable membrane offered the possibility to provide the required quantity of oxygen into the culture, while avoiding problems of foaming or shear stress generally linked to sparging. This aeration system allowed moreover to keep a known and constant k(L)a value through cultures up to 400 h. Oxygen uptake rate (OUR) was measured on-line with a very good accuracy of +/-5%, and the specific OUR for a CHO cell line was determined during batch (growth phase) and continuous culture as, respectively, equal to 2. 85x10(-13) and 2.54x10(-13) mol O(2) cell(-1) h(-1). It was also shown that OUR continuous monitoring gives actually more information about the metabolic state of the culture than the cell concentration itself, especially during transition phases like the end of the growth phase in a batch culture.
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Affiliation(s)
- P Ducommun
- Institute of Chemical Engineering, Swiss Federal Institute of Technology (EPFL), CH-1015, Lausanne, Switzerland
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Schneider M, Alaoui ME, Stockar UV, Marison IW. Batch cultures of a hybridoma cell line performed with in situ ammonia removal. Enzyme Microb Technol 1997. [DOI: 10.1016/s0141-0229(96)00122-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Stoll TS, Muhlethaler K, von Stockar U, Marison IW. Systematic improvement of a chemically-defined protein-free medium for hybridoma growth and monoclonal antibody production. J Biotechnol 1996; 45:111-23. [PMID: 9147446 DOI: 10.1016/0168-1656(95)00153-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A chemically-defined protein-free medium (FMX-Turbodoma) has been improved for the production of monoclonal IgA antibodies by hybridoma cells, using a systematic method. Cell growth rate, IgA production, activity and molecular weight pattern have been used as optimization criteria. Of potentially important supplements, glucose, glutamine, Pluronic acid F-68 as well as several amino acids had significant beneficial effects. A determination of amino acids profiles via HPLC analysis allowed the formulation of a balanced medium. Unbalanced supplementations of amino acids were found undesirable because of the toxicity of some amino acids at high concentration. Compared with the basal medium, the maximum viable cell and final IgA concentrations in the final version of the protein-free medium were increased by 130% and 700%, respectively, whereas the IgA molecular weight pattern and in vitro activity were not affected. The IgA production was even higher than in a serum-containing medium (RPMI 1640 + 10% FCS) and the price of the protein-free medium is about 20% of this serum-containing medium. This makes such a protein-free medium very convenient for laboratory and large-scale production.
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Affiliation(s)
- T S Stoll
- Institute of Chemical Engineering, Swiss Federal Institute of Technology, Lausanne, Switzerland
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Stoll T, Perregaux C, von Stockar U, Marison IW. Production of immunoglobulin A in different reactor configurations. Cytotechnology 1995; 17:53-63. [DOI: 10.1007/bf00749221] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/1994] [Accepted: 11/11/1994] [Indexed: 11/25/2022] Open
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