RESUMEN
This work describes the wettability and biological performance of Zn- and Cu-containing CaP-based coatings prepared by micro-arc oxidation on pure titanium (Ti) and novel Ti-40Nb alloy. Good hydrophilic properties of all the coatings were demonstrated by the low contact angles with liquids, not exceeding 45°. An increase in the applied voltage led to an increase of the coating roughness and porosity, thereby reducing the contact angles to 6° with water and to 17° with glycerol. The free surface energy of 75 ± 3 mJ/m2 for all the coatings were determined. Polar component was calculated as the main component of surface energy, caused by the presence of strong polar PO43- and OH- bonds. In vitro studies showed that low Cu and Zn amounts (~0.4 at.%) in the coatings promoted high motility of human adipose-derived multipotent mesenchymal stromal cells (hAMMSC) on the implant/cell interface and subsequent cell ability to differentiate into osteoblasts. In vivo study demonstrated 100% ectopic bone formation only on the surface of the CaP coating on Ti. The Zn- and Cu-containing CaP coatings on both substrates and the CaP coating on the Ti-40Nb alloy slightly decreased the incidence of ectopic osteogenesis down to 67%. The MAO coatings showed antibacterial efficacy against Staphylococcus aureus and can be arranged as follows: Zn-CaP/Ti > Cu-CaP/TiNb, Zn-CaP/TiNb > Cu-CaP/Ti.
RESUMEN
The osteogenic, cytotoxic, and antibacterial activities of polysaccharide (PS-SC) and flavonoid (F-SC) fractions isolated from the leaves extract of Saussurea controversa were studied in vitro. F-SC consists of the five quercetin glycosides in the ratio 2:8:10:1:4, which were isolated from the leaves extract of S. controversa and have been characterized previously. PS-SC was first isolated from the leaves extract of S. controversa and has been described. PS-SC consists in 30 compounds is characterized by a high degree of heterogeneity with a heterogeneity index of 19.74. The Mw and Mn of PS-SC were 108.6 and 5.5 kDa, respectively. Structural fragments are represented by galactose, arabinose, xylose, glucose, uronic acids, mannose, and rhamnose in a 10.1:3.3:2.2:2.1:1.7:0.9:0.5 molar ratio. F-SC as compared with PS-SC showed in vitro microbicidal (50 g/L) and better bacteriostatic (6.25 g/L versus 25 g/L of PS-SC) effects against the 24-h growth of Staphylococcus aureus strain 209 P and a 21-day absence of cytotoxicity on human adipose-derived multipotent mesenchymal stromal cells (hAMMSCs). Both fractions (PS-SC>F-SC) at doses of 10-50 mg/L stimulated differentiation of hAMMSCs into secreting osteoblasts accompanied by local mineralization of extracellular matrix. These fractions of S. controversa and especially F-SC, might be promising peroral drugs in the complex treatment of bone fractures and for prophylaxis of their infectious complications.
