Redox-responsive phosphonate-functionalized poly(beta-amino ester) gels and cryogels

Poly(beta-amino ester) networks have gained attention as a class of degradable polymers for biomedical applications, particularly as scaffolds for tissue engineering. In this work, two novel phosphonated diamines (one containing a redox-responsive disulfide group) are reacted with diacrylates via aza-Michael addition reaction to form acrylate terminated poly(beta-amino ester)s which are subsequently used as macromolecular precursors for fabrication of degradable gels and cryogels. The degradation rates of the gels and cryogels are monitored in phosphate buffer saline (PBS) and dithiothreitol (DTT), and the degradation times are found to range from hours to months depending on the design of chemical structure. The in vitro cytotoxicities of the degradation products are assessed with mouse embryonic fibroblast cells (NIH 3T3) and human osteosarcoma cells (Saos-2). The tailorability of the degradation rates and the non-toxicity of the degradation products make these poly(beta-amino ester) gels and cryogels good candidates as scaffolds for tissue engineering applications.