Event Abstract Back to Event Implantable microdevices for monitoring and feed-back intervention with respect to the tumor microenvironment: A feasibility study Johannes F. Clauss1*, Martin Brischwein1 and Bernhard Wolf1 1 Technische Universitaet Muenchen, Heinz Nixdorf Lehrstuhl für Medizinische Elektronik, Germany Background and aim. After surgery, the resection border of many solid tumors (e.g. brain cancer) frequently needs to be monitored for recurrent disease. Imaging techniques are principally used (MRI), but the monitoring intervals may be too long relating to tumor relapse. From a clinical point of view, a local and dynamic monitoring of pH (and pO2) with microdevices implanted at the cancer resection border could be beneficial for a closer, ambulant follow-up of patients. Ideally, such microdevices could be established as closed-loop-systems by combination with a local, targeted delivery of drugs. Methods. In a feasibility study, a prototype of an implantable microdevice for the measurement of pH and pO2 in body tissues has been set up. In order to achieve the required long-term stability of electrochemical microsensors, methods of in-situ self calibration have been developed and evaluated (Eminaga, 2013). Issues of implant form and technology, bidirectional communication, energy consumption, packaging and closed-loop local intervention and drug delivery have been included in the considerations. Results. So far, the fabrication of smart, implantable devices actively remaining for > 1 year in the body appears feasible. It is still unclear however, if the extreme specifications for pH (and pO2) sensor signal stability can be met even with sophisticated in situ self-calibration methods. For pH sensing, the prevention of reference potential drift is particularly important. With respect to closed-loop actuation, electrochemical methods may offer the feasibility of a local oxygenation by controlled electrolysis to counteract hypoxia. Technologies for local drug application are still in their infancy and urgently need further R&D efforts. Conclusions / Discussion. Currently, the prototype implants are in a stage of in-vitro testing. In case a satisfying reliability can be obtained – either with or without components for closed-loop intervention - the next step will be an evaluation in test animals. References Eminaga, Y., Brischwein, M., Becker, S., Wiest, J. Clauss, J., Wolf, B., Sensors & Actuators B 177 (2013), 785-791 Keywords: Tumor growth, Drug Targeting, implants, Oxygen Consumption, pH Conference: 4th Annual Meeting of the International Society of Proton Dynamics in Cancer, Garching, Germany, 10 Oct - 12 Oct, 2013. Presentation Type: Abstract Topic: 8. Metabolic imaging Citation: Clauss JF, Brischwein M and Wolf B (2014). Implantable microdevices for monitoring and feed-back intervention with respect to the tumor microenvironment: A feasibility study. Front. Pharmacol. Conference Abstract: 4th Annual Meeting of the International Society of Proton Dynamics in Cancer. doi: 10.3389/conf.fphar.2014.61.00014 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Dec 2013; Published Online: 07 Feb 2014. * Correspondence: Dr. Johannes F Clauss, Technische Universitaet Muenchen, Heinz Nixdorf Lehrstuhl für Medizinische Elektronik, Munich, BY, 80333, Germany, clauss@tum.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Johannes F Clauss Martin Brischwein Bernhard Wolf Google Johannes F Clauss Martin Brischwein Bernhard Wolf Google Scholar Johannes F Clauss Martin Brischwein Bernhard Wolf PubMed Johannes F Clauss Martin Brischwein Bernhard Wolf Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.