Introducing Disulfide Bonds into Polyester Biomaterials via Nucleophilic Thiol-yne Polymerization

Polyesters are a widely used class of biomaterials thanks to their (bio)degradability and tunable thermomechanical properties. Introducing dynamic disulfide bonds into their backbone enables them to be degraded through different routes and also imparts self-healing properties. However, while numerous polymerization protocols exist with which to introduce disulfide bonds into linear polymers, these methods lack the versatility needed to produce materials with diverse thermomechanical properties. In this work, nucleophilic thiol-yne polymerization was employed to synthesize polymers with a controllable amount of disulfide bonds in the backbone. The crystallinity and, hence, the thermomechanical properties of these polymers were tuned through the variation of different parameters such as disulfide bond content, polymer backbone conformational features (i.e., E/Z isomerism), and monomer combinations. Moreover, polymer degradability was confirmed by leveraging the reversible disulfide bonds in the presence of chemical stimuli. Finally, the cytocompatibility of these polymers was demonstrated, suggesting their potential use as polymeric biomaterials.