In Vitro System for Evaluation of Biosensors in Controlled Dynamic Environmental Conditions

Rapid in vitro evaluation of sensors and biosensors in conditions replicating in vivo physiological environments is desirable for improved preclinical evaluation. A two-part testing system with buffer exchange and simultaneous control of temperature, gas, and soluble analyte was developed. The system includes programmable incubators, peristaltic pumps, and gas and buffer metering subsystems. A reusable flow cell with windows for optical interrogation was developed to house multiple biosensor samples within the testing system where all of them can be examined simultaneously. The verification of the system environmental outputs indicates the accuracy within absolute errors of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.59 ~\mu \text{M}$ </tex-math></inline-formula> for oxygen and 5.5 mg/dL for glucose, and relative standard deviations of oxygen and glucose of 2.01% and 2.16%, respectively, at steady state, making it well suited for in vitro evaluation of biosensors. The evaluation of the system with model phosphorescence oxygen and glucose biosensors demonstrates the system’s capabilities in replicating several relevant parameters of the in vivo environment. This system, and future iterations of it, can increase the rate and throughput for testing biosensors, accelerating translation from the benchtop to the bedside in the future.