title: PEG-grafted chitosan nanoparticles as an injectable carrier for sustained protein release.
abstract: The development of injectable nanoparticulate "stealth" carriers for protein delivery is a major challenge. The objective of this work was to investigate the possibility of achieving the controlled release of a model protein, insulin, from PEG-grafted chitosan (PEG-g-chitosan) nanoparticles (mean diameter 150-300 nm) prepared by the ion gelation method. Insulin was efficiently incorporated into the nanoparticles, and reached as high as 38%. In vitro release showed that it could control the insulin release by choosing the composition, loading and release temperature. We observed that the composition of the nanoparticle surface (C/O ratio) increased from 2.40 to 3.23, with an increase in the incubation time. Therefore, we concluded that during this time, insulin release from PEG-g-chitosan nanoparticles followed a diffusion mechanism in which erosion was negligible. The experiments also demonstrated that PEG-g-chitosan helped to maintain the natural structure of the protein entrapped in the nanoparticles.
authors.affiliation: Key Laboratory of Functional Polymer Materials, Ministry Education, and Institute of Polymer Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China. zhangxinge@nankai.edu.cn
authors.forename: X G
authors.initials: XG
authors.lastname: Zhang
authors.forename: D Y
authors.initials: DY
authors.lastname: Teng
authors.forename: Z M
authors.initials: ZM
authors.lastname: Wu
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: D M
authors.initials: DM
authors.lastname: Yu
authors.forename: C X
authors.initials: CX
authors.lastname: Li
mesh_terms: D002021:Buffers; D055598:Chemical Phenomena; D048271:Chitosan / Q000737:chemistry*; D002942:Circular Dichroism; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000737:chemistry; D007267:Injections; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry*; D011506:Proteins / Q000008:administration & dosage* / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D002021:Buffers; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D007328:Insulin; D010710:Phosphates; D011506:Proteins; D011092:Polyethylene Glycols; D048271:Chitosan