Amino-yne Reaction\nfor the Synthesis of Degradable\nHydrogels: Study of the Cleavage of β‑Aminoacrylate Cross-Links

This work addresses a study of PEG-derived hydrogels\nbased on β-aminoacrylate\ncross-links and obtained by amino-yne click chemistry, using a β-aminoacrylate-based\nmodel molecule as reference. The pH-triggered cleavage of the β-aminoacrylate\nbonds was monitored confirming not only the release of the conjugated\namine but also the formation of a mixture of chemical species that\ndepends on the acidity of the medium. Moreover, overall hydrogel degradation\nrates were able to be adjusted by modifying pH, temperature, polymer\nconcentration, or the amine selected as linker of PEG chains. In particular,\nthe labile nature of the β-aminoacrylate bond was confirmed\neven under physiological conditions (pH 7.4, 37 °C), leading\nto long-term material degradation. The release and recovery of the\nconjugated amine after the cleavage of the β-aminoacrylate bonds\nwas demonstrated at both acidic and physiological pH, mimicking the\nresults acquired through model molecule studies.