4D printing of biodegradable intestinal drug delivery devices with shape-memory effect

Expanding devices designed to physically facilitate the permeation of drugs across the gastrointestinal mucosa are gaining attention for the oral delivery of therapeutic macromolecules. The ideal system should be biodegradable with latex-like properties, allowing it to withstand gut movement without breaking prematurely and preventing intestinal obstruction or damage. A highly foldable and elastic device is desirable because it can fit into commercial capsules by being compressed into confined spaces. However, this compression has limits due to the device's tendency to spring back to its original shape driven by stored elastic energy after deformation. This challenge can be addressed by using shape-memory polymers. In this work, we report a photo-crosslinkable resin suitable for 3D printing by digital light processing that yields an elastomer with latex-like properties, shape-recovery at body temperature, and degradation within 6 h under simulated intestinal conditions. Thermal shape-memory was conferred by adding stearyl(acrylate) to poly(β-aminoester)-based inks, achieving high elasticity (>700 %) and strength (>7.5 MPa), along with strain-hardening properties.