Hyaluronic acid/poly-L-lysine bilayered silica nanoparticles enhance the osteogenic differentiation of human mesenchymal stem cells

Herein, we evaluate the influence of a PLL–HA bilayer on the surface of silica nanoparticles on their capacity to induce the osteogenic differentiation of human bone marrow stem cells (hBMSCs), as a function of their concentration (50 μg mL⁻¹, 25 μg mL⁻¹ and 12.5 μg mL⁻¹). To this purpose, we synthesized silica nanoparticles (diameter of 250 nm; ζ-potential of −25 mV) that were coated with PLL–HA (diameter of 560 nm; ζ-potential of −35 mV). The cell viability, cell proliferation, protein quantification (i.e. MTS, DNA and ALP, respectively) and gene expression (of osteogenesis-related genes: ALP, osteocalcin, collagen type I, bone sialoprotein, Runx-2, osteopontin and osterix) were monitored, for 21 days. We observed the overexpression of most of the tested osteogenic transcripts in the hBMSCs cultured with SiO₂–PLL–HA, at concentrations of 25 μg mL⁻¹ and 12.5 μg mL⁻¹. These results indicate that the proposed nanoparticles temporarily improve the osteogenic differentiation of hBMSCs at low nanoparticle concentrations.