Crosslinkable PEO-PPO-PEO-based reverse thermo-responsive gels as potentially injectable materials.

This paper describes the functionalization and crosslinking of PluronicRTM derivatives in aqueous solution at 37 degrees C. Pluronic dimethacrylate was obtained by reacting native PEO-PPO-PEO triblocks with methacryloyl chloride and then crosslinking them by free radical polymerization at 37 degrees C, using a redox system. The resulting gel and its rheological behavior were characterized by different techniques. The swelling study of the crosslinked polymer was indicative of its reverse thermo-responsive behavior, as illustrated by the almost 800% water uptake of the polymer at 37 degrees C, as opposed to the 1600% attained by the polymer at 25 degrees C. As expected, while the Pluronic dimethacrylate gel displayed an Ec value of 142.5 +/- 29.7 kPa at 37 degrees C, the crosslinked system attained a Young's modulus three times higher: 415.2 +/- 45.7 kPa. Finally, the environmental SEM analysis revealed the porous microstructure of the crosslinked gels.