[Secretion of niche signal molecules in conditions of osteogenic differentiation of multipotent mesenchymal stromal cells induced by textured calcium phosphate coating].

Secretion of 21 cytokines, chemokines and growth factors (LIF, SCF, SDF-1a, SCGF-b, M-CSF, MCP-3, MIF, MIG, TRAIL, GRO-a; IL-1a, IL-2ra, IL-3, IL-12(p40), IL-16, IL-18, HGF, TNF-b, b-NGF, IFN-a2, CTACK) has been studied in vitro in the culture of human adipose-derived multipotent mesenchymal stromal cells (hAMMSCs) in conditions of its osteogenic differentiation caused by 14-day contact with calcium phosphate (CP) surface with different roughness. Bilateral X-ray amorphous CP coatings were prepared on the samples of commercially pure titanium in the anodal regime using a micro-arc method. An aqueous solution prepared from 20 wt% phosphoric acid, 6 wt% dissolved hydrohyapatite nanopowder (particle diameter 10-30 nm with single agglomerates up to 100 nm), and 9 wt% dissolved calcium carbonate was used to obtain CP coating. hAMMSCs isolated from lipoaspirate were co-cultured after 4 passages with the CP-coated samples at final concentration of 1.5´105 viable karyocytes per 1.5 mL of standard nutrition medium (without osteogenic stimulators) for 14 days (a determination of [CD45,34,14,20], CD73, CD90 и CD105 cell immunophenotype; an analysis of secretory activity) and 21 days (alizarin red S staining of culture) with medium replacement every 3-4 days. Under conditions of in vitro contact with rough CP coating hAMMSCs differentiated into osteoblasts synthesizing the mineralized bone matrix; this was accompanied by 2-3-fold increasing ratio of [CD45,34,14,20]+ hemopoietic cells. The following humoral factors of hemopoietic niches acted as the signal molecules escalating in vitro the hemopoietic base in 14 days of differentiating three-dimensional culture of hAMMSCs: either leukemia inhibitory factor (LIF) and stem cell factor (SCF) cytokines under mean index of CP roughness Ra=2.4-2.6 mm or stromal derived factor-1 (SDF-1a, CXCL12 chemokine) under Ra=3.1-4.4 mm.