TY - JOUR
T1 - Reproducibility warning
T2 - The curious case of polyethylene glycol 6000 and spheroid cell culture
AU - Serrati, Simona
AU - Martinelli, Chiara
AU - Palazzo, Antonio
AU - Iacobazzi, Rosa Maria
AU - Perrone, Mara
AU - Ong, Quy K.
AU - Luo, Zhi
AU - Bekdemir, Ahmet
AU - Pinto, Giulia
AU - Cavalleri, Ornella
AU - Cutrignelli, Annalisa
AU - Laquintana, Valentino
AU - Denora, Nunzio
AU - Stellacci, Francesco
AU - Krol, Silke
N1 - Funding Information:
The author(s) received no specific funding for this work. The authors are grateful to Dr. Roberto Santoliquido from Alfatest s.r.l. for the triple SEC measurements.
Publisher Copyright:
Copyright: © 2020 Serrati et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020
Y1 - 2020
N2 - Reproducibility of results is essential for a well-designed and conducted experiment. Several reasons may originate failure in reproducing data, such as selective reporting, low statistical power, or poor analysis. In this study, we used PEG6000 samples from different distributors and tested their capability inducing spheroid formation upon surface coating. MALDI-MS, NMR, FTIR, and Triple SEC analysis of the different PEG60000s showed nearly identical physicochemical properties different, with only minor differences in mass and hydrodynamic radius, and AFM analysis showed no significant differences in the surface coatings obtained with the available PEG6000s. Despite these similarities, just one showed a highly reproducible formation of spheroids with different cell lines, such as HT-29, HeLa, Caco2, and PANC-1. Using the peculiar PEG6000 sample and a reference PEG6000 chosen amongst the others as control, we tested the effect of the cell/PEG interaction by incubating cells in the PEG solution prior to cell plating. These experiments indicate that the spheroid formation is due to direct interaction of the polymer with the cells rather than by interaction of cells with the coated surfaces. The experiments point out that for biological entities, such as cells or tissues, even very small differences in impurities or minimal variations in the starting product can have a very strong impact on the reproducibility of data.
AB - Reproducibility of results is essential for a well-designed and conducted experiment. Several reasons may originate failure in reproducing data, such as selective reporting, low statistical power, or poor analysis. In this study, we used PEG6000 samples from different distributors and tested their capability inducing spheroid formation upon surface coating. MALDI-MS, NMR, FTIR, and Triple SEC analysis of the different PEG60000s showed nearly identical physicochemical properties different, with only minor differences in mass and hydrodynamic radius, and AFM analysis showed no significant differences in the surface coatings obtained with the available PEG6000s. Despite these similarities, just one showed a highly reproducible formation of spheroids with different cell lines, such as HT-29, HeLa, Caco2, and PANC-1. Using the peculiar PEG6000 sample and a reference PEG6000 chosen amongst the others as control, we tested the effect of the cell/PEG interaction by incubating cells in the PEG solution prior to cell plating. These experiments indicate that the spheroid formation is due to direct interaction of the polymer with the cells rather than by interaction of cells with the coated surfaces. The experiments point out that for biological entities, such as cells or tissues, even very small differences in impurities or minimal variations in the starting product can have a very strong impact on the reproducibility of data.
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U2 - 10.1371/journal.pone.0224002
DO - 10.1371/journal.pone.0224002
M3 - Article
C2 - 32191706
AN - SCOPUS:85081965800
VL - 15
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 3
M1 - e0224002
ER -