Permeability Effects on the Efficiency of Antioxidant Nanoreactors

摘要

Enzyme-loaded polymeric vesicles, or polymer-somes, can be regarded as nanoreactors, which, for example, can be applied as artificial organelles. We implemented a naturally occurring enzymatic cascade reaction in two types of polymer-somes, which are known to possess different permeability properties. The selected cascade reaction involved the: antioxidant enzymes superoxide dismutase (SOD1) and catalase (CAT) for conibating oxidative stress. The activities of both enzymes were investigated by spectrophotometric and electrochemical assays. Whereas the SOD1 substrate (the radical anion superoxide, O2~(·-)) was able to penetrate both membranes equally well, the CAT substrate (H2O2) showed different rates of difiusion. When O2~(·-) was generated inside polymersomes filled with both SODl and CAT, the activities of the two systems were comparable again.