title: pH sensitive swelling and releasing behavior of nano-gels based on polyaspartamide graft copolymers.
abstract: pH sensitive nano-gels based on polyaspartamide graft copolymers are prepared by UV crosslinking the self-assembled nano-aggregates in the presence of a series of hydrophobic and hydrophilic grafting segments. While the physical nano-aggregates dissociate via ionization of the pH sensitive moiety, the nano-gels synthesized in this study swell instead. The chemical structure and morphology of the resulting nano-gels were analyzed using FTIR, (1)H FTNMR, and TEM. The pH dependence of the particle size, 120-250 nm, was investigated using a light scattering analyzer. The swelling behavior of the nano-cores under acidic conditions triggered abrupt release of the drug; this pH dependence occurs reversibly and quickly. The nano-gels prepared may have endosomal rupturing characteristics, as their buffering capacity is as strong as that of uncrosslinked nano-aggregates. The nano-gels synthesized as such possess potential application as sustained releasing drug carriers for intracellular delivery.
authors.affiliation: School of Chemical Engineering, Theranostic Macromolecules Research Center, Sungkyunkwan University, Suwon, Kyunggi, Republic of Korea.
authors.forename: Sunmi
authors.initials: S
authors.lastname: Kim
authors.forename: Ji-Heung
authors.initials: JH
authors.lastname: Kim
authors.forename: Dukjoon
authors.initials: D
authors.lastname: Kim
mesh_terms: D003692:Delayed-Action Preparations / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D005782:Gels / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011108:Polymers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays; D017155:Wettability
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005782:Gels; D011108:Polymers