Poly(Ethylene Glycol) Dimethacrylates with Cleavable Ketal Sites: Precursors for Cleavable PEG-Hydrogels.
The authors introduce poly(ethylene glycol) (PEG) based macromonomers containing acid-labile ketal moieties as well as terminal methacrylate units that are amenable to radical polymerization. The synthesis of PEGs of different molecular weights (ranging from 2000 to 13 000 g mol-1with polydispersities <1.15) with a central ketal unit (PEG-ketal-diol) and their conversion to PEG-ketal-dimethacrylates (PEG-ketal-DMA) is introduced. Degradation rates of both PEG-ketal-diols and PEG-ketal-DMA are investigated by in situ1H NMR kinetic studies in deuterated phosphate buffer. Hydrogels containing 0, 5, or 10 wt% of PEG-ketal-DMA and 100, 95, or 90 wt% of PEG-DMA, respectively, are synthesized and disintegration of the gels is investigated in buffer at different pH values. Visible disintegration of the gels appears at pH 5 for hydrogels containing PEG-ketal-DMA, whereas no visible degradation is observed at all at neutral pH or for PEG hydrogels without PEG-ketal-DMA.
Institute of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.|Department of Dermatology, University Medical Center Mainz, Langenbeckstr. 1, 55131, Mainz, Germany.|Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128, Mainz, Germany.
Hannah
H
Pohlit
Institute of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.|Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128, Mainz, Germany.
Daniel
D
Leibig
Institute of Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.
Holger
H
Frey
D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D058105:Polymerization
D001672:Biocompatible Materials; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
PEG; acid-labile; degradation studies; drug delivery; in situ NMR kinetics; ketal