title: Development and application of a microfabricated multimodal neural catheter for neuroscience.
abstract: We present a microfabricated neural catheter for real-time continuous monitoring of multiple physiological, biochemical and electrophysiological variables that are critical to the diagnosis and treatment of evolving brain injury. The first generation neural catheter was realized by polyimide-based micromachining and a spiral rolling packaging method. The mechanical design and electrical operation of the microsensors were optimized and tailored for multimodal monitoring in rat brain such that the potential thermal, chemical and electrical crosstalk among the microsensors as well as errors from micro-environmental fluctuations are minimized. In vitro cytotoxicity analyses suggest that the developed neural catheters are minimally toxic to rat cortical neuronal cultures. In addition, in vivo histopathology results showed neither acute nor chronic inflammation for 7 days post implantation. The performance of the neural catheter was assessed in an in vivo needle prick model as a translational replica of a "mini" traumatic brain injury. It successfully monitored the expected transient brain oxygen, temperature, regional cerebral blood flow, and DC potential changes during the passage of spreading depolarization waves. We envisage that the developed multimodal neural catheter can be used to decipher the causes and consequences of secondary brain injury processes with high spatial and temporal resolution while reducing the potential for iatrogenic injury inherent to current use of multiple invasive probes.
authors.affiliation: Cushing Neuromonitoring Laboratory, Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA. cli11@nshs.edu.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Li
authors.affiliation: Microsystem and BioMEMS Laboratory, University of Cincinnati, Cincinnati, OH, 45221, USA.
authors.forename: Zhizhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Cushing Neuromonitoring Laboratory, Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA.
authors.forename: Kanokwan
authors.initials: K
authors.lastname: Limnuson
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, 11549, USA.
authors.forename: Cletus
authors.initials: C
authors.lastname: Cheyuo
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, 11549, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Microsystem and BioMEMS Laboratory, University of Cincinnati, Cincinnati, OH, 45221, USA.
authors.forename: Chong H
authors.initials: CH
authors.lastname: Ahn
authors.affiliation: Cushing Neuromonitoring Laboratory, Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA.|Department of Neurosurgery, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, 11549, USA.
authors.forename: Raj K
authors.initials: RK
authors.lastname: Narayan
authors.affiliation: Department of Neurosurgery, University of Cincinnati (UC) Neuroscience Institute, UC College of Medicine, Cincinnati, OH, 45219, USA.
authors.forename: Jed A
authors.initials: JA
authors.lastname: Hartings
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000473:pathology / Q000503:physiopathology*; D057785:Catheters; D013181:Cortical Spreading Depression; D004567:Electrodes, Implanted; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012117:Resins, Synthetic
chemical_list: D012117:Resins, Synthetic; C029945:polyimide resin
keywords: Brain temperature; Cortical spreading depression; Direct-current electrocorticography; Flexible substrate; Multimodal monitoring; Oxygen tension; Regional cerebral blood flow