Modeling and measuring glucose diffusion and consumption by colorectal cancer spheroids in hanging drops using integrated biosensors  

作　　者：Nassim Rousset Rubén López Sandoval Mario Matteo Modena Andreas Hierlemann Patrick M.Misun 

机构地区：[1]ETH Zürich,Department of Biosystems Science and Engineering,Bio Engineering Laboratory,Mattenstrasse 26,CH-4058 Basel,Switzerland

出　　处：《Microsystems & Nanoengineering》2022年第1期193-210,共18页微系统与纳米工程（英文）

基　　金：N.R.acknowledges financial support from a doctoral scholarship(FRQNT 199851)from the Fonds de Recherche du Québec—Nature et Technologies.R.L.S.acknowledges financial support from a scholarship(LCF/BQ/EU19/11710046)from the“La Caixa”Foundation;We acknowledge the help of Christian Lohasz,ETH Zürich,with the cell culture,maintenance,and characterization of HCT116 spheroids.We acknowledge the help of Flavio Bonanini,ETH Zürich,with the determination of cell seeding densities and control of HCT116 growth dynamics;We acknowledge the help of Stefan Strebel,University of Basel,and Felix Franke,ETH Zürich,with developing the mathematical models.

摘　　要：As 3D in vitro tissue models become more pervasive,their built-in nutrient,metabolite,compound,and waste gradients increase biological relevance at the cost of analysis simplicity.Investigating these gradients and the resulting metabolic heterogeneity requires invasive and time-consuming methods.An alternative is using electrochemical biosensors and measuring concentrations around the tissue model to obtain size-dependent metabolism data.With our hanging-dropintegrated enzymatic glucose biosensors,we conducted current measurements within hanging-drop compartments hosting spheroids formed from the human colorectal carcinoma cell line HCT116.We developed a physics-based mathematical model of analyte consumption and transport,considering(1)diffusion and enzymatic conversion of glucose to form hydrogen peroxide(H_(2)O_(2))by the glucose-oxidase-based hydrogel functionalization of our biosensors at the microscale;(2)H_(2)O_(2)oxidation at the electrode surface,leading to amperometric H_(2)O_(2)readout;(3)glucose diffusion and glucose consumption by cancer cells in a spherical tissue model at the microscale;(4)glucose and H_(2)O_(2)transport in our hangingdrop compartments at the macroscale;and(5)solvent evaporation,leading to glucose and H_(2)O_(2)upconcentration.Our model relates the measured currents to the glucose concentrations generating the currents.The low limit of detection of our biosensors(0.4±0.1μM),combined with our current-fitting method,enabled us to reveal glucose dynamics within our system.By measuring glucose dynamics in hanging-drop compartments populated by cancer spheroids of various sizes,we could infer glucose distributions within the spheroid,which will help translate in vitro 3D tissue model results to in vivo.

关 键 词：DIFFUSION HANGING SIMPLICITY 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] R735[自动化与计算机技术—控制科学与工程]