title: In vitro degradation and drug-release properties of water-soluble chitosan cross-linked oxidized sodium alginate core-shell microgels.
abstract: Hydrogels based on sodium alginate (SA) have already been widely used in biomedical applications using Ca(2+) as a cross-linker; however, these hydrogels tend to disintegrate in electrolyte solutions. To solve this problem, we present a kind of oxidized sodium alginate (OSA) microgel using water-soluble chitosan (WSC) as a cross-linker. This microgel was successfully prepared via an emulsion cross-linking technique at room temperature. The microgel was cross-linked by the formation of both Schiff base bonds and inter-polyelectrolyte complexes, which can efficiently eliminate the disintegration of the microgel in electrolyte solutions. Morphological properties of the resulting microgels were determined by transmission electron microscopy (TEM), hydrodynamic diameters of the microgels were characterized by dynamic light scattering (DLS). The objective of this work was to achieve the colon-specific delivery of an anti-ulcerative colitis drug. 5-Aminosalicylic acid (5-ASA) was chosen as a model drug and the in vitro drug-release profile was established in buffer solutions with 0.1 M HCl/NaCl (pH 1.2) and 0.1 M phosphate-buffered saline (PBS, pH 7.4) at 37°C. The microgel was incubated in 0.1 M PBS (pH 7.4) at 37°C to determine its degradation behavior. Cell cytotoxicity (tested by MTT assay) showed that this microgel had no significant cytotoxicity. These results indicated that this microgel prepared by introducing WSC into OSA may have potential applications in oral controlled drug-delivery systems. Therefore, the OSA/WSC microgel may be a useful carrier for the colon-specific delivery of anti-inflammatory drugs including 5-ASA and the enhanced therapeutic effect of ulcerative colitis.
authors.affiliation: a State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province , Lanzhou , 730000 , P. R. China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Mingzhu
authors.initials: M
authors.lastname: Liu
authors.forename: Shaoyu
authors.initials: S
authors.lastname: Lii
authors.forename: Chunmei
authors.initials: C
authors.lastname: Gao
authors.forename: Jiucun
authors.initials: J
authors.lastname: Chen
mesh_terms: D000284:Administration, Oral; D000464:Alginates / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000493:pharmacokinetics; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016923:Cell Death; D048271:Chitosan / Q000737:chemistry; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000378:metabolism; D016503:Drug Delivery Systems; D065546:Drug Liberation; D004573:Electrolytes / Q000737:chemistry; D005782:Gels / Q000138:chemical synthesis / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D057809:HEK293 Cells; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D057446:Hydrodynamics; D019804:Mesalamine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010084:Oxidation-Reduction; D012996:Solutions; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D004573:Electrolytes; D005782:Gels; D006603:Hexuronic Acids; D012996:Solutions; D014867:Water; D019804:Mesalamine; D020723:Glucuronic Acid; D048271:Chitosan