title: Monitoring the ex-vivo expansion of human mesenchymal stem/stromal cells in xeno-free microcarrier-based reactor systems by MIR spectroscopy.
abstract: Human mesenchymal stem/stromal cells (MSCs) have received considerable attention in the field of cell-based therapies due to their high differentiation potential and ability to modulate immune responses. However, since these cells can only be isolated in very low quantities, successful realization of these therapies requires MSCs ex-vivo expansion to achieve relevant cell doses. The metabolic activity is one of the parameters often monitored during MSCs cultivation by using expensive multi-analytical methods, some of them time-consuming. The present work evaluates the use of mid-infrared (MIR) spectroscopy, through rapid and economic high-throughput analyses associated to multivariate data analysis, to monitor three different MSCs cultivation runs conducted in spinner flasks, under xeno-free culture conditions, which differ in the type of microcarriers used and the culture feeding strategy applied. After evaluating diverse spectral preprocessing techniques, the optimized partial least square (PLS) regression models based on the MIR spectra to estimate the glucose, lactate and ammonia concentrations yielded high coefficients of determination (R(2)  ≥ 0.98, ≥0.98, and ≥0.94, respectively) and low prediction errors (RMSECV ≤ 4.7%, ≤4.4% and ≤5.7%, respectively). Besides PLS models valid for specific expansion protocols, a robust model simultaneously valid for the three processes was also built for predicting glucose, lactate and ammonia, yielding a R(2) of 0.95, 0.97 and 0.86, and a RMSECV of 0.33, 0.57, and 0.09 mM, respectively. Therefore, MIR spectroscopy combined with multivariate data analysis represents a promising tool for both optimization and control of MSCs expansion processes. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:447-455, 2016.
authors.affiliation: Engineering Faculty, Catholic University of Portugal, Rio de Mouro, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Rosa
authors.affiliation: Engineering Faculty, Catholic University of Portugal, Rio de Mouro, Portugal.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Sales
authors.affiliation: Dept. of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade De Lisboa, Av. Rovisco Pais, Lisboa, 1049-001, Portugal.
authors.forename: Joana G
authors.initials: JG
authors.lastname: Carmelo
authors.affiliation: Dept. of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade De Lisboa, Av. Rovisco Pais, Lisboa, 1049-001, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandes-Platzgummer
authors.affiliation: Dept. of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade De Lisboa, Av. Rovisco Pais, Lisboa, 1049-001, Portugal.
authors.forename: Cláudia L
authors.initials: CL
authors.lastname: da Silva
authors.affiliation: ISEL-Instituto Superior De Engenharia De Lisboa, Rua Conselheiro Emídio Navarro, 1, Lisboa, 1959-007, Portugal.|Institute of Telecommunications, Instituto Superior Técnico, Av. Rovisco Pais, Lisboa, 1049-001, Portugal.
authors.forename: Marta B
authors.initials: MB
authors.lastname: Lopes
authors.affiliation: ISEL-Instituto Superior De Engenharia De Lisboa, Rua Conselheiro Emídio Navarro, 1, Lisboa, 1959-007, Portugal.
authors.forename: Cecília R C
authors.initials: CR
authors.lastname: Calado
mesh_terms: D019149:Bioreactors; D018929:Cell Culture Techniques; D057166:High-Throughput Screening Assays; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D015999:Multivariate Analysis; D019265:Spectroscopy, Near-Infrared
keywords: MIR spectroscopy; high-throughput analysis; mesenchymal stem/stromal cells