How to reduce superoxide anion concentration using antioxidant nanoreactors

In order to fight oxidative stress we developed antioxidant nanoreactors based on encapsulation of Cu/Zn superoxide dismutase or its mimics in amphiphilic copolymer nanovesicles whose membranes are oxygen permeable. The nanovesicles, made of poly-(2methyloxazoline)poly(dimethylsiloxane)-poly(2-methyloxazoline), successfully encapsulated the protein/mimics during their self-assembly process and were stable for more than one month. Testing with superoxide anions generated by pulse radiolysis demonstrated that the antioxidant agent remains active inside the nanovesicles and detoxifies the superoxide radical in situ. The triblock copolymer membrane of our nanovesicle plays a double role: both to shield the sensitive protein and to selectively allow superoxide and dioxygen to penetrate to the inner space of the vesicle. A simple and robust system, the antioxidant nanoreactor represents a new direction for developing medical applications for the treatment of oxidative stress.