Proliferation and osteogenic response of MC3T3‐E1 pre‐osteoblastic cells on porous zirconia ceramics stabilized with magnesia or yttria

Abstract

Dense zirconia ceramics are used in bone applications due to their mechanical strength and biocompatibility, but lack osseointegration. A porous interface in contact with bone tissue may lead to better bone bonding but the biological properties of porous zirconia are not widely explored. The present study focuses on the manufacturing of an yttria- (YSZ) and a magnesia-stabilized (MgSZ) porous zirconia, and on their in vitro biological investigation. The sintered ceramics had similar characteristics of porosity, pore size and interconnectivity. Their elastic moduli and compressive strength values were within the range of the values of human cortical bone. MC3T3-E1 pre-osteoblasts were used to investigate the proliferation, alkaline phosphatase (ALP) activity, collagen deposition and expression profile of four genes involved in bone metabolism of cells on porous ceramics. Scanning electron and fluorescence microscopy were employed to visualize cell morphology and growth. Pre-osteoblasts adhered well on both ceramics but cell numbers on YSZ were higher. Cells exhibited an increase in ALP activity and collagen deposition after 14 days on both MgSZ and YSZ, with higher levels on YSZ. Real-time quantitative polymerase chain reaction (qPCR) showed that the expression of bone sialoprotein (Bsp) and collagen type I (col1aI) were significantly higher on YSZ. No significant differences were found in their ability to regulate the early gene expression of Runx2 and Alp. Nevertheless, the biomineralized calcium content was similar on both ceramics after 21 days, indicating that despite chemical differences, both scaffolds direct the pre-osteoblasts toward a mature state capable of mineralizing the extracellular matrix.

Effects of NSAIDs on the osteogenic differentiation of human adipose tissue-derived stromal cells

“…Effect of NSAID s on capacity of hADSC to acquire osteogenic features. (a) hADSC s were cultured for 14 days in the presence of NSAID s (10 −6 m ) in 10 m m β‐glycerol‐2‐phosphate and 50 μg/ ml ascorbic acid osteogenic medium, and alkaline phosphatase ( ALP ) activity was measured as previously described . Results are presented as enzyme units normalized to cell number.…”

“…(b) hADSC s were treated for 7 days in the presence of NSAID s (10 −6 m ) in osteogenic medium, and gene expression of RUNX 2 , ALP and Osteocalcin ( OC ) was examined by multiplex semi‐quantitative PCR . (c) hADSC s were cultured for 21 days in the presence of NSAID s (10 −6 m ) in osteogenic medium, and mineral deposition was measured by Alizarin Red S staining as previously described . Results are shown as OD 550 nm normalized to cell number and represent the mean ± SEM of n = 6 samples; * P ≤ 0.05.…”

“…Calcium‐rich deposits representing the final stage of mineralization were visualized by Alizarin Red S (ARS) (Sigma, St. Louis, MO, USA) staining and quantified by dye extraction, as previously described . Absorbance was measured at 550 nm with a spectrophotometer (SpectraMax M2, Molecular Devices Inc.).…”

Effect of Porosity of Alumina and Zirconia Ceramics toward Pre-Osteoblast Response

“…Ceramic sample preparation and the cell seeding procedure were performed as previously described (Hadjicharalambous et al, 2015b ). Cells (5 × 10 4 cells) were seeded onto the samples in a 30 μL cell suspension in primary medium.…”

“…In previous studies, we investigated the osteogenic potential of pre-osteoblasts on porous magnesia and yttria-stabilized zirconia ceramics (Hadjicharalambous et al, 2015b ), as well as the pre-osteoblastic cell response on zirconia, alumina, and zirconia/alumina composite (Hadjicharalambous et al, 2015a ). The objective of this study was to investigate the effect of zirconia and alumina ceramic substrate porosity on cellular adhesion and proliferation.…”