Fucoidan ()/Polydopamine Composite-Modified Surface Promotes Osteogenic Potential of Periodontal Ligament Stem Cells.

Fucoidan, a marine-sulfated polysaccharide derived from brown algae, has been recently spotlighted as a natural biomaterial for use in bone formation and regeneration. Current research explores the osteoinductive and osteoconductive properties of fucoidan-based composites for bone tissue engineering applications. The utility of fucoidan in a bone tissue regeneration environment necessitates a better understanding of how fucoidan regulates osteogenic processes at the molecular level.

The relationship between the structures of periphery ligands and the DNA binding mode of [Ru(II)(1,10-phenanthroline)(L1L2)dipyrido[3,2-a:2',3'-c]phenazine](n+) (L1=Cl or pyridine and L2=pyridine, n=1,2).

The binding modes of the [Ru(II)(1,10-phenanthroline)(L(1)L(2)) dipyrido[3,2-a:2',3'-c]phenazine](2+) {[Ru(phen)(py) Cl dppz](+) (L(1)=Cl, L(2)=pyridine) and ([Ru(phen)(py)(2)dppz](2+) (L(1)=L(2)=pyridine)} to native DNA is compared to that of the [Ru(II)(1,10-phenanthroline)(2)dipyrido[3,2-a:2',3'-c]phenazine](2+) complex ([Ru(phen)(2)dppz](2+)) by various spectroscopic and hydrodynamic methods including electric absorption, linear dichroism (LD), fluorescence spectroscopy, and viscometric titration. All measured properties, including red-shift and hypochromism in the dppz absorption band, nearly perpendicular molecular plane of the dppz ligand with respect to the local DNA helix axis, prohibition of the ethidium binding, the light switch effect and binding stoichiometry, increase in the viscosity upon binding to DNA, increase in the melting temperature are in agreement with classical intercalation of dppz ligand of the [Ru(phen)(2)dppz](2+) complex, in which both phenanthroline ligand anchored to the DNA phosphate groups by electrostatic interaction. [Ru(phen)(py)(2) dppz](2+) and [Ru(phen)(py) Cl dppz](+) complexes had one of the phenanthroline ligand replaced by either two pyridine ligands or one pyridine plus a chlorine ion.