title: Fabrication and characterization of a self-crosslinking chitosan hydrogel under mild conditions without the use of strong bases.
abstract: Self-crosslinking chitosan hydrogels are a highly suitable material for biomedical applications owing to their biodegradability and biocompatibility. However, strong bases, such as sodium hydroxide, which are often used in the preparation of such hydrogels, are known to affect biocompatibility and even destroy the bioactive factors or drug payload of the hydrogel. In the present study, strong bases were replaced by sodium chloride (NaCl) and phosphate buffer saline (PBS, pH=7.4), which were used as gelling solutions for hydrogel fabrication via the freeze-melting-neutralization method. Non-cytotoxicity was showed in MTT assay for hydrogel. Our findings suggest that hydrogel microstructure and physical properties may be adjusted by modifying parameters, such as concentration, temperature, and pH, during the gelling process. Furthermore, the present hydrogel was found to exhibit pH-and ionic strength-responsive properties and may be utilized as a stimulus-responsive material for biomedical applications such as controlled drug release.
authors.affiliation: Department of Dental Materials, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China. Electronic address: xuyx@hsc.pku.edu.cn.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Dental Materials, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China. Electronic address: hanjianmin@bjmu.edu.cn.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Dental Materials, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China. Electronic address: hong196lin@sina.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
keywords: Chitosan; Ionic strength; Self-crosslinking hydrogel; Stimulus-responsive