title: Preparation of monodisperse chitosan microcapsules with hollow structures using the SPG membrane emulsification technique.
abstract: We describe herein successful preparations of monodisperse chitosan microcapsules with hollow structures using the SPG membrane emulsification technique. Two preparation procedures were examined in this study. In the first method, monodisperse calcium alginate microspheres were prepared and then coated with unmodified chitosan. Subsequently, tripolyphosphate treatment was conducted to physically cross-link chitosan and solubilize the alginate core at the same time. In the second method, photo-cross-linkable chitosan was coated onto the monodisperse calcium alginate microspheres, followed by UV irradiation to chemically cross-link the chitosan shell and tripolyphosphate treatment to solubilize the core. For both methods, it was determined that the average diameters of the chitosan microcapsules depended on those of the calcium alginate microparticles and that the microcapsules have hollow structures. In addition, the first physical cross-linking method using tripolyphosphate was found to be preferable to obtain the hollow structure, compared with the second method using chemical cross-linking by UV irradiation. This was because of the difference in the resistance to permeation of the solubilized alginate through the chitosan shell layers.
authors: Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. akamatsu@cc.kogakuin.ac.jp
authors: Kazuki
authors: K
authors: Akamatsu
authors: Wei
authors: W
authors: Chen
authors: Yukimitsu
authors: Y
authors: Suzuki
authors: Taichi
authors: T
authors: Ito
authors: Aiko
authors: A
authors: Nakao
authors: Takashi
authors: T
authors: Sugawara
authors: Ryuji
authors: R
authors: Kikuchi
authors: Shin-ichi
authors: S
authors: Nakao
mesh_terms: D000464:Alginates / Q000737:chemistry; D002214:Capsules; D048271:Chitosan / Q000737:chemistry*; D004655:Emulsions; D005898:Glass / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008567:Membranes, Artificial; D011122:Polyphosphates / Q000737:chemistry; D016062:Porosity; D012995:Solubility
chemical_list: D000464:Alginates; D002214:Capsules; D004655:Emulsions; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D011122:Polyphosphates; D020723:Glucuronic Acid; D048271:Chitosan; C005692:triphosphoric acid