title: PEGylation of brain-derived neurotrophic factor for preserved biological activity and enhanced spinal cord distribution.
abstract: Brain-derived neurotrophic factor (BDNF) was covalently attached to polyethylene glycol (PEG) in order to enhance delivery to the spinal cord via the cerebrospinal fluid (intrathecal administration). By varying reaction conditions, mixtures of BDNF covalently attached to one (primary), two (secondary), three (tertiary), or more (higher order) PEG molecules were produced. The biological activity of each resulting conjugate mixture was assessed with the goal of identifying a relationship between the number of PEG molecules attached to BDNF and biological activity. A high degree of in vitro biological activity was maintained in mixtures enriched in primary and secondary conjugate products, while a substantial reduction in biological activity was observed in mixtures with tertiary and higher order conjugates. When a biologically active mixture of PEG-BDNF was administered intrathecally, it displayed a significantly improved half-life in the cerebrospinal fluid and an enhanced penetration into spinal cord tissue relative to native BDNF. Results from these studies suggest a PEGylation strategy that preserves the biological activity of the protein while also improving the half-life of the protein in vivo. Furthermore, PEGylation may be a promising approach for enhancing intrathecal delivery of therapeutic proteins with potential for treating disease and injury in the spinal cord.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado at Boulder, 424 UCB, 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: Evan M
authors.initials: EM
authors.lastname: Sloane
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Harrison
authors.forename: Klarika K
authors.initials: KK
authors.lastname: Douvas
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Potter
authors.forename: Travis S
authors.initials: TS
authors.lastname: Hughes
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Chavez
authors.forename: Kirk
authors.initials: K
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: D000447:Aldehydes / Q000737:chemistry; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000737:chemistry* / Q000378:metabolism*; D016503:Drug Delivery Systems; D004952:Esters / Q000737:chemistry; D007278:Injections, Spinal; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D011092:Polyethylene Glycols / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: D000447:Aldehydes; D019208:Brain-Derived Neurotrophic Factor; D004952:Esters; D011092:Polyethylene Glycols