title: Enhancing the Gelation and Bioactivity of Injectable Silk Fibroin Hydrogel with Laponite Nanoplatelets.
abstract: Regenerated silk fibroin (RSF) of Bombyx mori silk fiber is a promising natural material for bone defect repair. However, a lack of specific integrin and growth factor for osteoinduction significantly hinders its application in this area. In this study, the role of Laponite nanoplatelet (LAP), a bioactive clay that can promote osteoblast growth, in the formation of RSF hydrogel, as well as the various properties of RSF/LAP hybrid hydrogel, was closely investigated. The results indicate that LAP could serve as a medium to accelerate hydrophobic interaction among the RSF molecules and a disruptor to limit the growth of β-sheet domain during the gelation of RSF. Rheological measurement suggests that the RSF/LAP hydrogel is injectable as it displays thixotropy in the room temperature. Proliferation and differentiation results of the primary osteoblasts encapsulated in hydrogel show that RSF/LAP hydrogel can promote the cell proliferation and enhance the osteogenic differentiation. The transcript levels for alkaline phosphatase, osteocalcin, osteopontin, and collagen type I osteogenic markers obviously improve with RSF/LAP hydrogel compared to the controls at 14 days, especially with the higher contents of LAP. Overall, the results suggest that the RSF/LAP hydrogel have great potential to be utilized as an injectable biomaterial for irregular bone defect repair.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors.forename: Dihan
authors.initials: D
authors.lastname: Su
authors.affiliation: Department of Orthopaedic Surgery, Zhongshan Hospital, State Key Laboratory of Molecular Engineering of Polymers, Fudan University , Shanghai 200032, China.
authors.forename: Libo
authors.initials: L
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Zhongshan Hospital, State Key Laboratory of Molecular Engineering of Polymers, Fudan University , Shanghai 200032, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science and Laboratory of Advanced Materials, Fudan University , Shanghai 200433, People's Republic of China.
authors.forename: Zhengzhong
authors.initials: Z
authors.lastname: Shao
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D012831:Bombyx / Q000737:chemistry; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005349:Fibroins / Q000494:pharmacology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D007267:Injections; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D017207:Rats, Sprague-Dawley; D012212:Rheology / Q000187:drug effects; D017640:Silicates / Q000494:pharmacology*; D013059:Spectrum Analysis, Raman; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D017640:Silicates; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D005349:Fibroins; C524813:laponite; D000469:Alkaline Phosphatase
keywords: clay; hybrid hydrogel; primary osteoblasts; reconstitute silk fibroin; thixotropy