Near‐Body‐Temperature Shape‐Memory PLA / PEG Self‐Reinforced Composite for Fused Deposition Modeling ( FDM )‐Printed Vascular Stents

Polylactic acid (PLA) is a promising biodegradable shape‐memory polymer for minimally invasive vascular stents, but its high glass transition temperature ( T g ≈60°C) hinders in vivo shape‐memory actuation and biomedical applications. This study addresses this challenge through a dual‐modification strategy: plasticization with polyethylene glycol 400 (PEG400) to reduce T g and reinforcement with PLA fiber to restore mechanical strength. The addition of 10 wt% PEG400 increased molecular chain mobility and reduced T g , while the incorporation of 10 phr PLA fibers introduced PLA‐derived reinforcing structures that helped compensate for the plasticization‐induced strength loss. As a result, the optimized L90P10‐F10 composite can achieve superior comprehensive performance: T g as low as 37.6°C, a high tensile strength up to 54 MPa, and the excellent shape‐memory properties: at 43°C the shape fixity ratio is 98.4%, the shape recovery ratio is 98.9%, and the recovery time is only 15.2 s. Finally, vascular stents were successfully fabricated via fused deposition modeling (FDM), which exhibited reversible compression–recovery cycles under clinically achievable mild hyperthermia.