Swelling and degradation of hydrogels synthesized with degradable poly(β-amino ester) crosslinkers

The synthesis of diacrylated poly(β-amino ester) crosslinkers, obtained from the oligomerization of di(ethylene glycol) diacrylate (DEGDA) and piperazine (PIPz), and their use in hydrogels are reported. In particular, the poly(β-amino ester) crosslinkers were used to study swelling and degradation properties of hydrogels made of N-vinylpyrrolidone and 2-hydroxy ethyl methacrylate. Poly(β-amino ester) crosslinkers with two different molecular weights (800 and 3000 g mol−1) and hydrogels with 1 and 3% crosslinker were studied. Swelling and degradation of the gels were monitored in phosphate buffered saline (pH = 7.4) at 37 °C. The swelling and degradation characteristics of the poly(β-amino ester) crosslinked hydrogels were then compared to hydrogels crosslinked with poly(ethylene glycol) diacrylate (PEGDA) of similar molecular weights. It was found that both swelling and degradation were faster in the poly(β-amino ester) crosslinked hydrogels, particularly for the highest molecular weight poly(β-amino ester) crosslinker.