title: Investigation of gelling behavior of thiolated chitosan in alkaline condition and its application in stent coating.
abstract: The gelling behaviors of thiolated chitosan (TCS) in alkaline condition were investigated. Thioglycolic acid was conjugated onto chitosan backbone through amide bond formation. The variations of thiol group content were monitored in presence of H2O2 or different pH values (pH 7.0, 8.0, 9.0) in dialysis mode. Different from the decreasing thiol group content upon time in acidic condition, increasing amount of thiol groups was detected in alkaline pH during 120 min dialysis attributed to alkaline hydrolysis of intra-molecular disulfide bonds. The extent of which was larger at higher pH values. Higher degree of thiolation, thiomer concentration or pH values promoted gelation of TCS. Entanglement and coagulation of chitosan molecule chains and re-arrangement of disulfide bonds acted closely and dynamically in the gelation process. Disulfide bonds, especially inter-molecular type, are formed by synergetic effects of thiol/disulfide interchange and thiol/thiol oxidation reactions. TCS coated vascular stent displayed wave-like microstructure of parallel ridges and grooves, which favored HUVECs adhesion and proliferation. The biocompatibility, peculiar morphology and thiol moieties of TCS as stent coating material appear application potential for vascular stent.
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China. Electronic address: kongming@ouc.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Kong
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Feng
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Cheng
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Marine Life Science, Ocean University of China, 5 No. Yushan Road, Qingdao 266003, Shandong Province, China. Electronic address: xgchen@ouc.edu.cn.
authors.forename: Xiguang
authors.initials: X
authors.lastname: Chen
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry* / Q000633:toxicity; D005782:Gels; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D044367:Phase Transition; D015607:Stents; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D005782:Gels; D013438:Sulfhydryl Compounds; D048271:Chitosan; D006861:Hydrogen Peroxide
keywords: Alkaline condition; Cardiovascular stent coating; Gelation; Thiolated chitosan