Computational design and analysis of biocompatible shape memory polymer-based self-expandable stent

Abstract Cardiovascular stents restore lumen patency, yet balloon-expandable designs may expand non-uniformly and traumatize vessels. A self-expandable, biodegradable stent is designed and computationally evaluated from shape-memory polymers (SMPs): poly( L -Lactic acid) (PLLA) and poly(lactic-co-glycolic acid) (PLGA). A hexagonal-nested lattice (Ø4 mm, length 40 mm, thickness 0.4 mm; rib width 0.5 mm; rib angle 120.39°; connector length 1 mm) was modeled in SOLIDWORKS and analyzed by finite elements. Physiological internal pressure (150 mmHg ≈ 0.02 MPa) assessed radial response and foreshortening across circumferential cell counts of 5, 6, and 7. Thermo-mechanical deployment followed the SMP sequence, heat to T g , cool, crimp, holding time, reheat (T g -PLLA ≈ 64 °C), to evaluate shape fixity and recovery. Reducing cells from 7 to 5 lowered peak von Mises stress (PLLA: ∼1.33 MPa–0.89 MPa), so the five-cell design was chosen for deployment. PLLA achieved high shape fixity (95 %) and near-complete recovery (>99 %) with negligible expansion stresses (10 −6 MPa), indicating controlled self-deployment. PLGA showed inferior shape-memory metrics and was not advanced to detailed stress comparison. SMP-based biodegradable stents can combine low deployment stress with adequate radial support, and the presented workflow provides a reproducible computational basis for subsequent prototyping and in vitro validation.