title: Effect of cold-setting calcium- and magnesium phosphate matrices on protein expression in osteoblastic cells.
abstract: Bone loss due to accidents or tissue diseases requires replacement of the structure by either autografts, allografts, or artificial materials. Reactive cements, which are based on calcium phosphate chemistry, are commonly used in nonload bearing areas such as the craniofacial region. Some of these materials are resorbed by the host under physiological conditions and replaced by bone. The aim of this study was to test different calcium and magnesium cement composites in vitro for their use as bone substitution material. Phase composition of calcium deficient hydroxyapatite (Ca(9) (PO(4) )(5) HPO(4) OH), brushite (CaHPO(4) ·2H(2) O), and struvite (MgNH(4) PO(4) ·6H(2) O) specimens has been determined by means of X-ray diffraction, and compressive strength was measured. Cell growth and activity of osteoblastic cells (MG 63) on the different surfaces was determined, and the expression of bone marker proteins was analyzed by western blotting. Cell activity normalized to cell number revealed higher activity of the osteoblasts on brushite and struvite when compared to hydroxyapatite and also the expression of osteoblastic marker proteins was highest on brushite scaffolds. While brushite sets under acidic conditions, formation of struvite occurs under physiological pH, similar to hydroxyapatite cements, providing the possibility of additional modifications with proteins or other active components.
authors.affiliation: Department of Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, Würzburg D-97070, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ewald
authors.forename: Kerstin
authors.initials: K
authors.lastname: Helmschrott
authors.forename: Georg
authors.initials: G
authors.lastname: Knebl
authors.forename: Nazia
authors.initials: N
authors.lastname: Mehrban
authors.forename: Liam M
authors.initials: LM
authors.lastname: Grover
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D017886:Durapatite / Q000494:pharmacology; D006801:Humans; D017616:Magnesium Compounds / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010710:Phosphates / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects*; D000069877:Struvite
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes; D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; C030781:magnesium phosphate; D017886:Durapatite; D000069877:Struvite; C494366:calcium phosphate, dibasic, dihydrate