Expanded perlite and barium sulfate as enablers for biomedical applications of 3D-printed PLA biocomposites: Thermo-mechanical properties, bacterial adhesion inhibition, and antimicrobial activity

Enhancing the performance of PLA biomaterials for scaffolding requires suitable mechanical properties, controlled surface features, and antibacterial activity. In this work, PLA-based biocomposite filaments were developed using expanded perlite of low (EPL) and high (EPH) density, along with barium sulfate with 10 (BS10) and 20 μm (BS20) particle sizes for 3D printing. Both fillers maintained the thermal stability of PLA, with a Tg around 58 °C. Melt flow indices (EP: 6–13; BS: 6–9 g/10 min) indicated good processability, while rheological analysis showed reduced viscoelasticity. EP tensile strength values remained within the range required for wound healing scaffolds (5–40 MPa). BS composites exhibited improved tensile properties, with BS10 reaching around 40 MPa across all loadings, and BS20 between 35 and 40 MPa, with optimal performance at 5 wt.%. Both EPH and BS20 increased surface roughness and decreased bacterial adhesion (up to 88%), highlighting their potential for functional PLA scaffolds.