title: Preparation and characterization of biodegradable nanoparticles entrapping immunodominant peptide conjugated with PEG for oral tolerance induction.
abstract: PEG-conjugated immunodominant peptides for collagen-induced arthritis (CIA) were prepared for oral tolerance induction instead of whole Type II collagen (CII), because a small peptide can be converted to a macromolecule soluble in methylene chloride by the coupling of poly-ethylene glycol (PEG). PEG-pep1 was synthesized from a peptide and mPEG-NH2 (Mw approximately 5000) using SPDP as a linker, whereas PEG-pep2 was prepared by the direct disulfide coupling between PEG-OD (Mw approximately 10,000) and the peptide. PEG-pep1 and PEG-pep2 were purified by gel permeation chromatography (GPC), and the peak fractions of GPC were identified by GPC and MALDI-TOF mass spectroscopy. The peptide coupling gave much earlier retention times for PEG-pep1 (11.26 min) and PEG-pep2 (10.61 min) than for mPEG-SPDP (15.63 min) and mPEG-OD (14.58 min). The Mw's of mPEG-NH2, mPEG-SPDP, PEG-pep1, mPEG-OD and PEG-pep2 were 5451, 5588, 7035, 10,360 and 11,826, respectively, suggesting that PEG-pep1 and PEG-pep2 of high purity could be obtained. The nanoparticles entrapping PEG-pep1 and PEG-pep2 (NP/PEG-pep1 and NP/PEG-pep2) were prepared by the o/w solvent evaporation method, whereas the peptide-loaded nanoparticles (NP/pep) were prepared by the w/o/w double emulsion method. Although all the nanoparticles had a similar spherical morphology under scanning electron microscopy, NP/pep showed up as having a larger mean size than the others, which was confirmed by dynamic light scattering analysis (NP/pep, 499.7+/-27.2 nm; NP/PEG-pep1, 333.0+/-16.8 nm; NP/PEG-pep2, 342.4+/-15.1 nm). The lower encapsulation efficiency of NP/pep (21.0+/-1.6%) than NP/PEG-pep1 (66.5+/-5.0%) and NP/PEG-pep2 (73.8+/-5.5%) can also be attributed to the preparation method. In in vitro release studies, NP/PEG-pep1 and NP/PEG-pep2 displayed a similar release profile, close to a linear release pattern, whereas NP/pep displayed a tri-phasic release profile. From these results, it was demonstrated that nanoparticles entrapping a PEG-conjugated peptide could be an alternative delivery method for the induction of oral tolerance rather than CII and peptide.
authors.affiliation: School of Nano Engineering, Inje University, Kimhae, Korea.
authors.forename: Woo-kyoung
authors.initials: WK
authors.lastname: Lee
authors.forename: Jong-yeun
authors.initials: JY
authors.lastname: Park
authors.forename: Sangho
authors.initials: S
authors.lastname: Jung
authors.forename: Chul Woo
authors.initials: CW
authors.lastname: Yang
authors.forename: Wan-Uk
authors.initials: WU
authors.lastname: Kim
authors.forename: Ho-Youn
authors.initials: HY
authors.lastname: Kim
authors.forename: Jae-Hun
authors.initials: JH
authors.lastname: Park
authors.forename: Jong-sang
authors.initials: JS
authors.lastname: Park
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005079:Excipients; D019044:Image Cytometry; D007108:Immune Tolerance / Q000187:drug effects*; D016056:Immunodominant Epitopes / Q000008:administration & dosage* / Q000737:chemistry; D051379:Mice; D008811:Mice, Inbred DBA; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D010581:Peyer's Patches / Q000737:chemistry / Q000276:immunology; D011092:Polyethylene Glycols / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology
chemical_list: D005079:Excipients; D016056:Immunodominant Epitopes; D011092:Polyethylene Glycols