title: Soluble silica inhibits osteoclast formation and bone resorption in vitro.
abstract: Several studies have suggested that silicon (Si) may be essential for the normal development of connective tissue and the skeleton. Positive effects of Si from the diet as well as from Si-containing biomaterials, such as bioactive glass 45S5 (BG), have been demonstrated. Studies have reported that Si stimulates osteoblast proliferation and differentiation. However, the effects of Si on osteoclasts have not been directly addressed. The purpose of the present in vitro study was to clarify if Si has regulatory effects on osteoclast formation and bone resorption. The effects of BG, BG dissolution extracts and Si containing cell culture medium were investigated in a mouse calvarial bone resorption assay and osteoclast formation assays (mouse bone marrow cultures and RAW264.7 cell cultures). We conclude from our results that Si causes significant inhibition of osteoclast phenotypic gene expressions, osteoclast formation and bone resorption in vitro. In conclusion, the present study suggests that Si has a dual nature in bone metabolism with stimulatory effects on osteoblasts and inhibitory effects on osteoclasts. This suggested property of Si might be interesting to further explore in future biomaterials for treatments of bone defects in patients.
authors.affiliation: Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy at University of Gothenburg, PO Box 450, SE-405 30 Göteborg, Sweden; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, PO Box 412, SE-405 30 Göteborg, Sweden. Electronic address: zivko.mladenovic@gu.se.
authors.forename: Živko
authors.initials: Ž
authors.lastname: Mladenović
authors.forename: Anders
authors.initials: A
authors.lastname: Johansson
authors.forename: Britta
authors.initials: B
authors.lastname: Willman
authors.forename: Kaveh
authors.initials: K
authors.lastname: Shahabi
authors.forename: Erik
authors.initials: E
authors.lastname: Björn
authors.forename: Maria
authors.initials: M
authors.lastname: Ransjö
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D001862:Bone Resorption / Q000473:pathology*; D002460:Cell Line; D002516:Ceramics / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005898:Glass; D007477:Ions; D051379:Mice; D009499:Neutral Red / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D010012:Osteogenesis / Q000187:drug effects / Q000235:genetics; D011419:Propidium / Q000378:metabolism; D012825:Silicon / Q000494:pharmacology; D012822:Silicon Dioxide / Q000494:pharmacology*; D012995:Solubility; D013054:Spectrophotometry, Atomic
chemical_list: D003470:Culture Media; D007477:Ions; C425330:bioactive glass 45S5; D009499:Neutral Red; D011419:Propidium; D012822:Silicon Dioxide; D012825:Silicon
keywords: Bioactive glass; Bone resorption; Osteoclastogenesis; Osteoclasts; Silicon