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.

Cytocompatibility of the selected calcium phosphate based bone cements: comparative study in human cell culture

“…Struvite was reported to promote osteoblasts proliferation in comparison to brushite and calcium—deficient HA, but it was not referred to the standard culture dish. Cell spreading was not addressed in this observation while bone-specific markers determined by Western blot were diminished [ 46 ]. Not only phase composition but also surface structure may influence capabilities to cell flattening.…”

Generation of composites for bone tissue-engineering applications consisting of gellan gum hydrogels mineralized with calcium and magnesium phosphate phases by enzymatic means

“…Pure MgP in the form of newberyite (MgHPO 4 ·3H 2 O) showed good cytocompatibility and supported colonization by osteoblastic cells (Tamimi et al ., ). Magnesium phosphate cements based on struvite (MgNH 4 PO 4 ·8H 2 O) have shown superior cytocompatibility to brushite (CaHPO 4 ·2H 2 O) and CDHA cements (Ewald et al ., ). In this study, the stimulatory effect was comparable for samples mineralized in media B–E, despite differences in Mg content (Tables , 3).…”

“…MgP is gaining interest as an alternative to CaP, due to its comparable cytocompatibility and ability to support osteoblast adhesion and expression of osteoblastic markers at the mRNA level (Tamimi et al ., ). Thanks to the cytocompatibility of MgP, bone cements based on MgP have been developed as alternatives to CaP cements (Ewald et al ., ; Klammert et al ., ; Mestres and Ginebra, ; Moseke et al ., ; Tay et al ., ). An additional justification for the use of magnesium phosphate‐based ceramics is their faster resorption in vivo compared to calcium phosphate‐based ceramics (Klammert et al ., ).…”

Systematic Assessment of Synthesized Tri-magnesium Phosphate Powders (Amorphous, Semi-crystalline and Crystalline) and Cements for Ceramic Bone Cement Applications

“…Recent studies into magnesium phosphates have been conducted due to higher strengths and faster resorption rates of these cements. Magnesium phosphate cement or ceramic compositions explored to date include [8,[24][25][26][27][28] .…”