title: Implantable Sensors for Regenerative Medicine.
abstract: The translation of many tissue engineering/regenerative medicine (TE/RM) therapies that demonstrate promise in vitro are delayed or abandoned due to reduced and inconsistent efficacy when implemented in more complex and clinically relevant preclinical in vivo models. Determining mechanistic reasons for impaired treatment efficacy is challenging after a regenerative therapy is implanted due to technical limitations in longitudinally measuring the progression of key environmental cues in vivo. The ability to acquire real-time measurements of environmental parameters of interest including strain, pressure, pH, temperature, oxygen tension, and specific biomarkers within the regenerative niche in situ would significantly enhance the information available to tissue engineers to monitor and evaluate mechanisms of functional healing or lack thereof. Continued advancements in material and fabrication technologies utilized by microelectromechanical systems (MEMSs) and the unique physical characteristics of passive magnetoelastic sensor platforms have created an opportunity to implant small, flexible, low-power sensors into preclinical in vivo models, and quantitatively measure environmental cues throughout healing. In this perspective article, we discuss the need for longitudinal measurements in TE/RM research, technical progress in MEMS and magnetoelastic approaches to implantable sensors, the potential application of implantable sensors to benefit preclinical TE/RM research, and the future directions of collaborative efforts at the intersection of these two important fields.
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332;Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.
authors.forename: Brett S
authors.initials: BS
authors.lastname: Klosterhoff
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332.
authors.forename: Melissa
authors.initials: M
authors.lastname: Tsang
authors.affiliation: Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Didi
authors.initials: D
authors.lastname: She
authors.affiliation: Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931.
authors.forename: Keat Ghee
authors.initials: KG
authors.lastname: Ong
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332;Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Allen
authors.affiliation: Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332;Department of Orthopaedics, Emory University, Atlanta, GA 30303;Atlanta Veteran's Affairs Medical Center, Decatur, GA 30033;Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332.
authors.forename: Nick J
authors.initials: NJ
authors.lastname: Willett
authors.affiliation: George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332;Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Guldberg
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D019736:Prostheses and Implants; D044968:Regenerative Medicine / Q000295:instrumentation*; D014159:Transducers