title: PEGylation of interleukin-10 for the mitigation of enhanced pain states.
abstract: The anti-inflammatory cytokine interleukin-10 (IL-10) shows promise for the treatment of neuropathic pain, but for IL-10 to be clinically useful as a short-term therapeutic its duration needs to be improved. In this study, IL-10 was covalently modified with polyethylene glycol (PEG) with the goal of stabilizing and increasing protein levels in the CSF to improve the efficacy of IL-10 for treating neuropathic pain. Two different PEGylation methods were explored in vitro to identify suitable PEGylated IL-10 products for subsequent in vivo testing. PEGylation of IL-10 by acylation yielded a highly PEGylated product with a 35-fold in vitro biological activity reduction. PEGylation of IL-10 by reductive amination yielded products with a minimal number of PEG molecules attached and in vitro biological activity reductions of approximately 3-fold. In vivo collections of cerebrospinal fluid after intrathecal administration demonstrated that 20 kDa PEG attachment to IL-10 increased the concentration of IL-10 in the cerebrospinal fluid over time. Relative to unmodified IL-10, the 20 kDa PEG-IL-10 product exhibited an increased therapeutic duration and magnitude in an animal model of neuropathic pain. This suggests that PEGylation is a viable strategy for the short-term treatment or, in conjunction with other approaches, the long-term treatment of enhanced pain states.
authors.affiliation: Department of Chemical & Biological Engineering, University of Colorado at Boulder, Boulder, Colorado 80309, USA.
authors.forename: Ryan G
authors.initials: RG
authors.lastname: Soderquist
authors.forename: Erin D
authors.initials: ED
authors.lastname: Milligan
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Harrison
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Chavez
authors.forename: Kirk W
authors.initials: KW
authors.lastname: Johnson
authors.forename: Linda R
authors.initials: LR
authors.lastname: Watkins
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Mahoney
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007278:Injections, Spinal; D016753:Interleukin-10 / Q000008:administration & dosage / Q000134:cerebrospinal fluid / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D051379:Mice; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D016753:Interleukin-10; D011092:Polyethylene Glycols