TY - JOUR
T1 - Spheroid-3D and Monolayer-2D Intestinal Electrochemical Biosensor for Toxicity/Viability Testing
T2 - Applications in Drug Screening, Food Safety, and Environmental Pollutant Analysis
AU - Flampouri, Evangelia
AU - Imar, Shahzad
AU - Oconnell, Kieran
AU - Singh, Baljit
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/3/22
Y1 - 2019/3/22
N2 - The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable cell numbers. Furthermore, the model intestinal toxicants diclofenac (DFC, pharmaceutical), okadaic acid (OA, food-safety), and mancozeb (MZB, environmental) were used for the functional evaluation of the proposed sensor using 2D and 3D culture formats. Sensor performance showed high consistency with conventional cell viability/cytotoxicity assays (MTT/CFDA-AM) for all toxicants, with the sensor IC 50 values matching the relevant viability LC 50 values at the 95% confidence interval range for 2D (DCF: 1.19-1.26 mM, MZB: 10.28-14.18 μM, OA: 40.91-77.13 nM) and 3D culture formats (DCF: 1.02-4.78 mM, MZB: 11.26-15.16 μM, OA: 162.09-179.67 nM). The presented results demonstrate the feasibility of the proposed sensor as a robust endpoint screening tool for both 2D and 3D cytotoxicity assessment.
AB - The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable cell numbers. Furthermore, the model intestinal toxicants diclofenac (DFC, pharmaceutical), okadaic acid (OA, food-safety), and mancozeb (MZB, environmental) were used for the functional evaluation of the proposed sensor using 2D and 3D culture formats. Sensor performance showed high consistency with conventional cell viability/cytotoxicity assays (MTT/CFDA-AM) for all toxicants, with the sensor IC 50 values matching the relevant viability LC 50 values at the 95% confidence interval range for 2D (DCF: 1.19-1.26 mM, MZB: 10.28-14.18 μM, OA: 40.91-77.13 nM) and 3D culture formats (DCF: 1.02-4.78 mM, MZB: 11.26-15.16 μM, OA: 162.09-179.67 nM). The presented results demonstrate the feasibility of the proposed sensor as a robust endpoint screening tool for both 2D and 3D cytotoxicity assessment.
KW - cytotoxicity
KW - screen-printed electrode
KW - spheroid-3D, electrochemical biosensor
KW - substrate and enzymatic product
KW - viability, nonspecific esterase
UR - http://www.scopus.com/inward/record.url?scp=85062334192&partnerID=8YFLogxK
U2 - 10.1021/acssensors.8b01490
DO - 10.1021/acssensors.8b01490
M3 - Article
C2 - 30698007
AN - SCOPUS:85062334192
SN - 2379-3694
VL - 4
SP - 660
EP - 669
JO - ACS Sensors
JF - ACS Sensors
IS - 3
ER -