New amphiphilic grafted copolymers based on polysaccharides

Original amphiphilic copolymers based on methylcellulose grafted on chitosan and hyaluronan are prepared and characterized. It is shown that the reductive amination is successful and may be realized in mild conditions such as to graft neutral methylcellulose chains randomly along the ionic polysaccharide backbone. The equilibrium between electrostatic repulsion between charged chains and hydrophobic attraction due to methylcellulose grafted chains controls the physical properties in solution. Especially, the presence of external salt or/and temperature increase favours a 3D-network formation or reinforce the gel-like behaviour of these systems. The new copolymers prepared are still biocompatible and may find application in a wide range of domains where thermo-sensitive physical gel formation is needed.