title: Bioactive SrO-SiO2 glass with well-ordered mesopores: characterization, physiochemistry and biological properties.
abstract: For a biomaterial to be considered suitable for bone repair it should ideally be both bioactive and have a capacity for controllable drug delivery; as such, mesoporous SiO(2) glass has been proposed as a new class of bone regeneration material by virtue of its high drug-loading ability and generally good biocompatibility. It does, however, have less than optimum bioactivity and controllable drug delivery properties. In this study, we incorporated strontium (Sr) into mesoporous SiO(2) in an effort to develop a bioactive mesoporous SrO-SiO(2) (Sr-Si) glass with the capacity to deliver Sr(2+) ions, as well as a drug, at a controlled rate, thereby producing a material better suited for bone repair. The effects of Sr(2+) on the structure, physiochemistry, drug delivery and biological properties of mesoporous Sr-Si glass were investigated. The prepared mesoporous Sr-Si glass was found to have an excellent release profile of bioactive Sr(2+) ions and dexamethasone, and the incorporation of Sr(2+) improved structural properties, such as mesopore size, pore volume and specific surface area, as well as rate of dissolution and protein adsorption. The mesoporous Sr-Si glass had no cytotoxic effects and its release of Sr(2+) and SiO(4)(4-) ions enhanced alkaline phosphatase activity - a marker of osteogenic cell differentiation - in human bone mesenchymal stem cells. Mesoporous Sr-Si glasses can be prepared to porous scaffolds which show a more sustained drug release. This study suggests that incorporating Sr(2+) into mesoporous SiO(2) glass produces a material with a more optimal drug delivery profile coupled with improved bioactivity, making it an excellent material for bone repair applications.
authors.affiliation: Institute for Materials Science, Dresden University of Technology, Dresden, Germany. chengtie.wu@qut.edu.au
authors.forename: Chengtie
authors.initials: C
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.forename: Michael
authors.initials: M
authors.lastname: Gelinsky
authors.forename: Yin
authors.initials: Y
authors.lastname: Xiao
authors.forename: Paul
authors.initials: P
authors.lastname: Simon
authors.forename: Renate
authors.initials: R
authors.lastname: Schulze
authors.forename: Thomas
authors.initials: T
authors.lastname: Doert
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Luo
authors.forename: Gianaurelio
authors.initials: G
authors.lastname: Cuniberti
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001826:Body Fluids / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D055598:Chemical Phenomena / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology; D016503:Drug Delivery Systems; D005898:Glass / Q000737:chemistry*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D008855:Microscopy, Electron, Scanning; D016062:Porosity / Q000187:drug effects; D011208:Powders; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013696:Temperature; D054457:Tissue Scaffolds / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D011208:Powders; C558454:bioactive SrO-SiO2 glass; D012710:Serum Albumin, Bovine; D003907:Dexamethasone; D000469:Alkaline Phosphatase