Preparation and characterization of an in situ crosslinkable glycol chitosan thermogel for biomedical applications

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 80; pp. 820 - 828
• Main Authors: Oh, Hye Min, Kang, Eunae, Li, Zhengzheng, Cho, Ik Sung, Kim, Da Eun, Mallick, Sudipta, Kang, Sun-Woong, Roh, Kyung-Ho, Huh, Kang Moo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.12.2019; 한국공업화학회
• Subjects: Chemical crosslinking; Glycol chitosan; Hydrogel; In situ crosslinkable hydrogel; Thermogelling; 화학공학; Glycol chitosan; Chemical crosslinking; Hydrogel; In situ crosslinkable hydrogel; Thermogelling
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2019.07.002

[Display omitted] •A new in situ crosslinkable thermogel system (M/SH-HGC) was successfully developed by mixing two kinds of glycol chitosan thermogels.•The M/SH-HGC thermogels retained not only thermogelling properties but also reactive functionalities for chemical crosslinking.•The M/SH-HGC thermogels exhibited enhanced and tunable physicochemical properties without significant cytotoxicity. Thermogels have been extensively utilized as one of representative in situ forming hydrogel systems for biomedical applications. However, most thermogels often suffer from a weak mechanical strength and low physical stability. To overcome these intrinsic weaknesses of conventional thermogels, we developed a new in situ crosslinkable thermogel system with enhanced and tunable physicochemical properties. Thermosensitive N-hexanoyl glycol chitosans (HGCs) were synthesized by N-hexanoylation of glycol chitosan and further modified to yield methacrylated HGCs (M-HGCs) and thiolated HGCs (SH-HGCs). A mixture of M-HGCs and SH-HGCs (M/SH-HGCs) retained not only their thermogelling properties but also their reactive functionalities for chemical crosslinking at physiological temperature. Compared to conventional thermogels, the M/SH-HGC thermogels showed enhanced mechanical properties due to physical and chemical crosslinking mechanisms. The physicochemical properties of the M/SH-HGC thermogels were characterized in terms of the sol–gel transition temperature, gelation time, mechanical strength, and biodegradability. They showed negligible toxicity in cells, and the in situ crosslinking step did not affect cell viability. These results suggest that our crosslinkable thermogel system is useful not only as a new in situ forming hydrogel but also as a biomaterial for various biomedical applications due to its thermogelling characteristics and enhanced and tunable physicochemical properties.