Amphiphilic Cholic-Acid-Modified Dextran Sulfate and its Application for the Controlled Delivery of Superoxide Dismutase

A novel amphiphilic and biodegradable polyelectrolyte DS-CA is prepared by the esterification of DS with CA. DS-CA can self-assemble into stable nanoparticles in water. SOD can effectively associate with DS-CA at pH?=?5.0 by virtue of electrostatic and hydrophobic interactions. SOD release from the complex nanoparticles is slow at pH?=?1.2. The release at pH?=?7.4 PBS shows an extended behavior and is tunable by changing the weight ratio of SOD to DS-CA as well as the CA substitution degree. Increasing the CA substitution degree of DS-CA can significantly enhance the cellular uptake of the loaded SOD. This study demonstrates that the amphiphilic DS-CA provides a promising strategy for oral delivery of protein/peptide drugs.