Shape-memory polymers are smart materials that have the ability to return from a deformed state to their original shape induced by an external stimulus, such as temperature change or light. Applications in robotics and photonics have been demonstrated, while medical applications are just emerging.

A smart polymer that can be triggered directly by biological activity has been synthesized by researchers from The enzymatically triggered shape memory polymer changes shape isothermally in response to enzymatic activity. Source: Syracuse University and Bucknell UniversitySyracuse University and Bucknell University. The biocompatible material responds directly to enzymatic activity and can do so under isothermal cell culture conditions.

Dual electrospinning, in which a high-voltage current is applied to two needle tips pumping two separate polymer solutions, was used for fabrication. The material combines Pellethane, a thermoplastic polyurethane elastomer used as an enzymatically stable shape memory component, and poly(ε-caprolactone) (PCL), a biodegradable polyester included as a shape fixing component vulnerable to enzymatic degradation.

Bulk enzymatic degradation tests showed that shape recovery is achieved by degradation of the PCL shape-fixing phase, and that both the materials and the process of enzymatic shape recovery are cytocompatible.

The researchers suggested that such smart polymers could be used to improve wound healing by responding to cues from regenerating tissue or targeted drug delivery.