title: A novel covalently crosslinked gel of alginate and silane with the ability to form bone-like apatite.
abstract: Hybrids consisting of bone-like apatite and biodegradable polymers are attractive materials for bone repair. We have shown that an alginate gel crosslinked covalently with ethylenediamine (EDA) enhances the repair of skin and nerves. In this study, we report a novel method for fabrication of an apatite-alginate nanohybrid using a simulated body fluid (SBF). Alginate was reacted with 3-aminopropyltriethoxysilane (APES), which gives silanol groups after hydrolysis, and/or EDA, by dehydration condensation using water-soluble carbodiimide to form gels. Modification of alginate with APES alone also gave a gel, because the alginate could be crosslinked by dehydration of silanol groups derived from APES. The gels obtained were soaked in a 1 mol/L CaCl2 solution and subsequently soaked in SBF. Apatite was formed on and inside the alginate gels modified with APES, whereas it was not formed on the gels without APES. Modification of alginate with silanol groups induced not only gel formation but also the apatite-forming ability on and inside the alginate gel in SBF. Consequently, a hydroxyapatite-alginate hybrid can be produced by modification of alginate with silanol groups and subsequent soaking in CaCl2 solution and SBF. Such a material is expected to be useful in bone repair.
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Kayo
authors.initials: K
authors.lastname: Hosoya
authors.forename: Chikara
authors.initials: C
authors.lastname: Ohtsuki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kawai
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kamitakahara
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ogata
authors.forename: Toshiki
authors.initials: T
authors.lastname: Miyazaki
authors.forename: Masao
authors.initials: M
authors.lastname: Tanihara
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002122:Calcium Chloride / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D005782:Gels; D008855:Microscopy, Electron, Scanning; D012821:Silanes / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000464:Alginates; D003432:Cross-Linking Reagents; D005782:Gels; D012821:Silanes; D012996:Solutions; C082343:silanol; D002122:Calcium Chloride; D002118:Calcium