Publié le 06/02/2020 par Chan-Seng Delphine
Thermoresponsive polymers with a lower or upper critical solution 
temperature (LCST and UCST respectively) are attractive smart materials 
in the field of biomedicine. The UCST behavior, i.e. reversible 
increased solubility upon increased temperature, is usually induced by 
hydrogen bonding or Coulomb interactions. Thus, this phenomenon is not 
expected for polyelectrolytes without specific counterion in water. In 
the context of the NANOTRANSMED project, the PECMAT and CMP teams in 
collaboration with the laboratory Biomaterials and Bioengineering 
(INSERM UMR_S 1121) and the laboratory of Modelisation and Molecular 
Simulation (CNRS UMR 7140) recently reported the synthesis and 
characterization of a cationic comb polymers with pentaarginine side 
chains exhibiting an UCST behavior (doi: 
10.1016/j.eurpolymj.2020.109528). This phenomenon was attributed and 
supported by molecular dynamic simulations to the stacking of the 
guanidinium groups of the arginine residues at low temperature.