Studies on a novel multi-sensitive hydrogel: influence of the biomimetic phosphorylcholine end-groups on the PEO-PPO-PEO tri-block co-polymers.

In the present study, a biomimetic phosphorylcholine group was employed in the end-capping modification of PEO-PPO-PEO tri-block co-polymers (Pluronic(®)). The structures of the resulting materials were characterized by (1)H-NMR and GPC. The effects of the additional phosphorylcholine end-groups to the thermo-sensitive sol-gel transition behaviors of the aqueous solutions of the resulting polymers were studied by rheology test in neutral (0.1 M NaCl) aqueous solutions and in acidic solutions (pH 3). It was found that the phosphorylcholine-end-capped Pluronic hydrogels still kept their thermo-sensitive mechanical properties with a slight change on the sol-gel transition behaviors. The phosphorylcholine-modified Pluronics exhibited a response to the change of the pH value, which made this kind of material a multi-sensitive hydrogel system. Also, the resulting polymers showed improved hemocompatibilities in the blood coagulation test using full human blood.