(Scheme 4) [70]. The molecular weight of the macroinitiator and the number of
added EO units determined the defined position of the acetal in the backbone.
Figure 1 shows the size exclusion chromatography (SEC) traces of the degradable
mPEG before and after acidic degradation, as well as its precursor. The two welldefined distributions of different molecular weights (dashed line) were attributed to
Scheme 3 Linear degradable PEGs according to Lynd, Hawker and colleagues [147]
Scheme 4 Synthesis of mPEG with a single cleavable unit at a defined position, according to [70]
Fig. 1 Size-exclusion chromatograms of degradable mPEG before (solid black line) and after
(dashed black line) degradation and that of the mPEG precursor (solid grey line). Adapted with
permission from [70]. Copyright 2013 American Chemical Society
From Biocompatible to Biodegradable: Poly(Ethylene Glycol)s with. . .
175
added EO units determined the defined position of the acetal in the backbone.
Figure 1 shows the size exclusion chromatography (SEC) traces of the degradable
mPEG before and after acidic degradation, as well as its precursor. The two welldefined distributions of different molecular weights (dashed line) were attributed to
Scheme 3 Linear degradable PEGs according to Lynd, Hawker and colleagues [147]
Scheme 4 Synthesis of mPEG with a single cleavable unit at a defined position, according to [70]
Fig. 1 Size-exclusion chromatograms of degradable mPEG before (solid black line) and after
(dashed black line) degradation and that of the mPEG precursor (solid grey line). Adapted with
permission from [70]. Copyright 2013 American Chemical Society
From Biocompatible to Biodegradable: Poly(Ethylene Glycol)s with. . .
175