The polymer synthesis and workup procedures were carried out as described elsewhere. Briefly, the initiator was added to a dried and N2 flushed Schlenk flask and dissolved in the respective amount of solvent. The monomer MeOzi was added, and the reaction mixture was heated to 130°C and stirred until complete consumption of the monomer, as was monitored by 1 H NMR spectroscopy. After consumption of MeOzi, the mixture was cooled to room temperature and the second block, PentOx, was added. The mixture was heated to 130°C overnight. The same procedure was repeated for the third block MeOzi. After confirmation of monomer consumption by 1 H NMR, the polymerization was terminated by addition of ethylisonipecotate at 50°C for 4 h. The solvent was removed under reduced pressure and the residue was transferred into a dialysis bag (MWCO 1 kDa, cellulose acetate) and dialysed against deionized water for two days with several water changes. Afterwards, the solution was recovered from the bag and lyophilized. Further information can be found in the Supporting Information (Table and Figure ).