Abstract
Background
21st century health care remains anchored to sporadic measurements of traditional physiologic variables such as heart rate, blood pressure, weight, physical exam findings and general biochemical values. Currently there is no sensor capable of monitoring in intra-cellular protein and gene level signaling in real-time and in-vivo. This gap between biological signaling and its translation into clinically relevant therapeutics targeting the individual has limited precision medicine approaches to heart and vascular diseases. Inflammatory processes have been implicated in numerous cardiovascular diseases providing an ideal target for using Biologically based-Implantable Electronic Devices (BIED) approaches.
Objective
We aimed to test an implantable electro-photonic biosensor system in which living cells are integrated within the BIED and 1) serve as the primary sensor element providing in-vivo, real-time monitoring of intra-cellular processes such as gene expression, protein signaling, and target pathway activation, and 2) provide intelligent biologically based-processing in which the the output reflects biological response to an event. The engineered sensor cells provide real-time monitoring and respond to prespecified biologic signals using green fluorescence protein (GFP). The fluorescence is then detected via the BIED's photonic system and the cellular response data transmitted providing remote monitoring capabilities to facilitate the development of innovative personalized therapeutics.
Methods
A biologically-based implantable biosensor (BIED) platform which provides fluorescence detection, data acquisition and transmission from living cells integrated within the device was tested. The sensor cells communicate with the surrounding implant environment via a biomembrane. NRK rat cells engineered to express GFP in response to NF-κB pathway activation were cultured and housed within the sensor. Prior implant studies confirmed NRK sensor cells remained viable for 21 days in-vivo as part of a fully functional implanted BIED hardware system. Ex-vivo experiments characterized the expected magnitude and time course of NRK response to TNF-α and Lipopolysaccharide (LPS) exposure used to elicit a proinflammatory inflammatory response. The biosensor was implanted in the subcutaneous space of male Sprague Dawley rats (n=2) for a total of 11 days consisting of a baseline post-surgical recovery period of 7 days, with subsequent challenge with intraperitoneal LPS on Day 8 and 96 hours of post LPS monitoring.
Results
Rats implanted with the Biological based sensor and challenged with intraperitoneal LPS showed real-time expression of GFP under NF-κB transcriptional control following time course similar to ex-vivo experiments (p<0.05) (Figure 1).
Figure 1. Implantable Cell-Embedded Biosensor
Conclusion
We present the first in-vivo use of a new class of BIEDs to detect biological cell response which may herald real-time personalize health management at the molecular and cellular level.
Acknowledgement/Funding
Clinical and Translational Sciences Institute-University of Rochester, Efferent Labs
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