A Method for in Vivo Quantification Of Cytokine IL-1β In The Rat Intrathecal Space

IL-1β is a potent pro-inflammatory cytokine critical to multiple pathologies in the central nervous system (CNS). Quantification of IL-1β in vivo is challenging due to pM range of IL-1β released in the spinal cord and also the terminal nature of cerebrospinal fluid (CSF) sampling in rodents. Herein we developed a robust in vivo device on stainless steel suitable for detection of IL-1β in the spinal cord of rats. This approach offers high sensitivity (3.2 pg mL^-1) and specificity to IL-1β. Also, a modified lumbar puncture method was employed to implant the device in the intrathecal space of male Sprague-Dawley (SD) rats under short-acting anesthesia, allowing minimal invasiveness, which provided the possibility of repeated measurement of IL-1β in the same animal. Our biosensing technology and the surgical method provide a universal platform for in vivo detection of diverse analytes in longitudinal, within-subject studies in the intrathecal space of rats to reduce the required number of experimental animals.