title: Shell cross-linked hyaluronic acid/polylysine layer-by-layer polyelectrolyte microcapsules prepared by removal of reducible hyaluronic acid microgel cores.
abstract: Shell cross-linked hollow polyelectrolyte microcapsules composed of hyaluronic acid (HA) and poly- l-lysine (PLL) were prepared by layer-by-layer (LBL) adsorption and subsequent core removal by a reductive agent. Disulfide cross-linked HA microgels were used as template core materials for the LBL deposition on the surface and removed by treatment of dithiothreitol at neutral pH condition. HA/PLL polyelectrolyte multilayers on the shell were chemically cross-linked via carbodiimide chemistry, and their physicochemical properties and drug release behaviors were investigated. Shell cross-linked HA/PLL polyelectrolyte microcapsules exhibited far enhanced physical stability against freeze-thaw cycles and acidic pH conditions compared to the un-cross-linked ones. The cross-linked HA/PLL multilayer shell also demonstrated pH responsive permeability, which became more permeable at low pH than at neutral pH. When bovine serum albumin (BSA), as a model protein drug, was loaded inside using the pH-dependent permeability, BSA release profiles from the microcapsules could be readily modulated by varying medium pH values or adding an HA digesting enzyme (hyaluronidase) in the incubation medium.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea.
authors.forename: Hyukjin
authors.initials: H
authors.lastname: Lee
authors.forename: Yongho
authors.initials: Y
authors.lastname: Jeong
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Park
mesh_terms: D000327:Adsorption; D000818:Animals; D002214:Capsules / Q000138:chemical synthesis*; D002417:Cattle; D003432:Cross-Linking Reagents / Q000138:chemical synthesis*; D005782:Gels; D006820:Hyaluronic Acid / Q000138:chemical synthesis*; D011107:Polylysine / Q000138:chemical synthesis*; D011108:Polymers / Q000138:chemical synthesis*; D019163:Reducing Agents / Q000737:chemistry
chemical_list: D002214:Capsules; D003432:Cross-Linking Reagents; D005782:Gels; D011108:Polymers; D019163:Reducing Agents; D011107:Polylysine; C002189:polyelectrolyte 60; D006820:Hyaluronic Acid