The cell proliferation was expressed as the number of living cells present on both groups of surfaces at day 3, 7, and 14 of culture.
Concomitantly, histomorphometry showed that formation, mineralization and remodeling of repair (primary) bone in the medulla were delayed in BSP−/− mice, with lower osteoid and osteoclast surfaces at day 15.
Pro-angiogenic factors (ANXA2, EPAS-1) were upregulated at TiOBlast and Osseospeed surfaces at day 7 [37].
Two studies reported expression of genes associated with osteoclastic activity and ECM degradation (cathepsin-K (CTSK), tartarate-resistant acid phosphatase (ACP5), and/or matrix metalloproteinases (MMPs)), on Osseospeed and TiOBlast surfaces at day 7 [37], and SLActive surfaces at day 14.
Osteopontin, an ECM protein essential for mineralization [53], was significantly upregulated on SLActive comparing to SLA surfaces at day 7 [35].
The key transcription factor osterix (Osx) was upregulated on the Osseospeed surface, but not TiOBlast at day 7 [36], while tissues adjacent to SLActive surfaces demonstrated comparatively greater BMP and Ras/MAPK expression compared to SLA surfaces at day 7 [35].
Osteocalcin, the most bone-specific ECM protein and a late marker of osteogenic differentiation [19], was significantly upregulated on Osseospeed (versus TiOBlast) surfaces at day 7 [36].
Key neurotrophic factors (brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NTF3)), essential for neuronal survival and differentiation during development [76], were significantly upregulated on SLActive versus SLA surfaces at day 7 suggesting an effect of surface modulation.
The growth of cells on the CNW and HGL surfaces, as well as on the uncoated Thermanox™ control surface, was measured by MTT assay at three time points over the total assay time of 7 days, with resulting data normalized to the TCPS control surface at day 7 (Fig. 4).
No cells were detected on the articular surface at day 0. Cells were detected on the articular surface at day 11 and day 20 under all experimental conditions.
