Water-actuated reversible shape-memory polydimethylsiloxane for potential biomedical applications

Shape memory polymers (SMPs) show great potential in biomedical fields. However, most of the SMPs are not suitable for use in the human body due to their deleteriousness and harsh actuation conditions. It is important to diversify SMPs that could be actuated in the human body environment. Herein, we construct a reversible shape-memory polydimethylsiloxane (RSMPDMS) based on a feasible strategy by deposing the PDMS-salt layer with dynamic micro-creases on the pure PDMS layer. Testing results reveal that it equips with self-expanding, bio-compatibility, drug storage-release and good mechanical toughness. The RSMPDMS could be variously shaped, such as ring, coil, and spiral. The prepared samples present efficient deformation-recovery with high mechanical stability during water absorption-desorption cycles. Moreover, the RSMPDMS is confirmed biocompatible by cell viability analysis and cell fluorescent labeling method, accompanied with efficient drug storage-release. The novel-designed RSMPDMS may contribute to the development of new shape memory biomedical materials.