# 3D-Printed Poly(lactic acid)/Poly(ethylene glycol) Scaffolds with Shape-Memory Effect near Physiological Temperature

## TL;DR

Researchers created 3D-printed scaffolds with shape-memory properties near body temperature, which could be useful for bone tissue engineering.

## Contribution

The study introduces a new method to tailor shape-memory performance in biocompatible scaffolds using PEG plasticization and gyroid structures.

## Key findings

- PLA/10 PEG scaffolds achieved 97% shape recovery at 40°C within 6 minutes.
- PEG concentration and gyroid structure significantly influence thermal transitions and shape-memory behavior.
- Compositional and structural changes were analyzed using ATR–FTIR, Raman, DSC, XRD, and SEM.

## Abstract

Biocompatible poly(lactic acid) (PLA) was plasticized with poly(ethylene glycol) (PEG) added at concentrations of 10, 15, and 20 wt.% relative to PLA, and then processed into gyroid triply periodic minimal surface (TPMS) scaffolds using fused filament fabrication (FFF) 3D printing. The influence of PEG concentration and gyroid structure (50% infill density) on thermal transitions, crystallinity, and low–temperature shape-memory performance was systematically investigated. The shape-memory effect (SME) of the PLA–based scaffolds was tailored through compositional control and structural design. Shape recovery under thermal activation at 40 °C and 50 °C was examined to reveal the correlation between composition and structure in governing low–temperature shape-memory behavior. The optimal composition (PLA/10 PEG, 50% gyroid infill) achieved shape recovery with a recovery ratio (Rr) of 97 ± 1% at 40 °C within 6 ± 1 min, demonstrating optimal shape-memory activation close to physiological temperature. Structural and morphological changes were characterized using ATR–FTIR, Raman spectroscopy, DSC, XRD, and SEM, providing comprehensive insight into the plasticization of the PLA matrix and its impact on structure–property relationships relevant to bone tissue engineering.