As summarized in Figure 1, encapsulated F-insulin wasreleased from polymersomes in response to the presence ofmonosaccharide in the medium (pH 7.4). The solution ofpolymersomes of 7 (1 mL) encapsulating F-insulin was chargedin a dialysis bag (MW cutoff of 10 000 Da), which was thendialyzed against 100 mL of phosphate buffer containingfructose (0.1 M) or glucose (0.3 M). During dialysis, a fractionof the buffer solution was taken at intervals of 30 min forfluorescence measurements. The release of F-insulin fromdisassembled polymersomes was observed from the measure-ment of emission spectra (λmax= 518 nm), which showed anincrease over the period of dialysis (Figure 4C). Withoutmonosaccharides, no fluorescence was observed during dialysisof polymersomes encapsulating F-insulin over the entire timeperiod of dialysis, indicating that polymersomes of PEG-b-PBOx did not release the encapsulated insulin without