title: Sodium dodecyl sulfate-induced rapid gelation of silk fibroin.
abstract: The in situ formation of injectable silk fibroin (SF) hydrogels have potential advantages over various other biomaterials due to the minimal invasiveness during application. Biomaterials need to gel rapidly under physiological conditions after injection. In the current paper, a novel way to accelerate SF gelation using an anionic surfactant, sodium dodecyl sulfate (SDS), as a gelling agent is reported. The mechanism of SDS-induced rapid gelation was determined. At low surfactant concentrations, hydrophobic interactions among the SF chains played a dominant role in the association, leading to decreased gelation time. At higher concentrations of surfactant, electrostatic repulsive forces among micellar aggregates gradually became dominant and gelation was hindered. Gel formation involves the connection of clusters formed by the accumulation of nanoparticles. This process is accompanied by the rapid formation of β-sheet structures due to hydrophobic and electrostatic interactions. It is expected that the silk hydrogel with short gelation time will be used as an injectable hydrogel in drug delivery or cartilage tissue engineering.
authors.affiliation: National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China.
authors.forename: Xilong
authors.initials: X
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Hou
authors.forename: Mingzhong
authors.initials: M
authors.lastname: Li
authors.forename: Jiangnan
authors.initials: J
authors.lastname: Wang
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Shenzhou
authors.initials: S
authors.lastname: Lu
mesh_terms: D002942:Circular Dichroism; D005349:Fibroins / Q000737:chemistry*; D005782:Gels; D047011:Silk / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013500:Surface Tension
chemical_list: D005782:Gels; D047011:Silk; D012967:Sodium Dodecyl Sulfate; D005349:Fibroins