An ROS-Responsive Antioxidative Macromolecular Prodrug of Caffeate for Uveitis Treatment

Uveitis is a sophisticated syndrome showing a high relevance with reactive oxygen species (ROS). Herein, an ROS-responsive PEGylated polypeptide based macromolecular prodrug of herbaceous antioxidant ethyl caffeate (EC) is designed via phenylboronic esters with improved solubility for the alleviation of uveitis. The antioxidative 4-hydroxybenzyl alcohol (HBA) and EC can be released from the macromolecular EC prodrug under the stimulation of ROS, which can effectively protect cells against oxidative stress-induced injury in an ROS-depletion way. The antioxidative and protective effects of the macromolecular EC prodrug in vivo are further verified in a uveitis mouse model. Overall, this work not only provides a handy method to synthesize a phenylboronic ester-bearing EC prodrug which is highly sensitive to pathological ROS, but also depicts a promising future to apply macromolecular antioxidative prodrugs in the treatment of uveitis as well as other ROS-related diseases.