# Pioneering Soundscapes: Investigating Commercial Fused Deposition Modelling Filament’s Potential for Ultrasound Technology in Bone Tissue Scaffolds

## TL;DR

This study explores the use of commercial 3D printing filaments for ultrasound-enhanced bone tissue scaffolds, showing promising mechanical and structural properties.

## Contribution

The novelty lies in combining FDM filaments with ultrasound technology for bone tissue scaffolds, demonstrating phase segregation and mechanical flexibility.

## Key findings

- PLA-PCL filaments successfully produced complex bone tissue scaffolds with phase segregation observed via SEM.
- PLA-PCL4060 and PLA-PCL5050 showed flexibility and responsiveness under ultrasound, as confirmed by three-point bending tests.
- Degradation experiments revealed the impact of porosity and gradients under ultrasound stimulation.

## Abstract

Daily exposure to various forces creates defects in the musculoskeletal system, leading to health issues, especially for bones. Bone tissue scaffolds and ultrasound technology are both utilized in research and in clinics to enhance bone tissue regeneration. This study aimed to investigate the potential of commercially available fused deposition modeling (FDM) filaments for ultrasound technology using X-ray diffraction (XRD), Raman spectroscopy, nanoindentation, three-point bending, and scanning electron microscopy (SEM) characterization methods. Customized FDM filaments were produced by combining polylactic acid (PLA) FDM filaments with medical-grade polycaprolactone (PCL). Using these, we observed the successful production of complex tissue scaffolds via PLAPCL4060 and PLAPCL5050 FDM filaments. Additionally, the presence of the contrast difference observed via SEM for PLAPCL4060 suggests phase segregation and a material that has both damping and activating characteristics under ultrasound propagation. Mechanical characterization provided hardness and elastic modulus values, while the three-point bending results proved the flexible nature of PLAPCL4060 and PLAPCL5050, which is important for their dynamicity and responsiveness under ultrasound propagation. Accelerated degradation experiments provided crucial information regarding the effect of the porosity and gradients of scaffolds under ultrasound stimulation. Future studies based on this approach will contribute to understanding the true potential of these filaments for bone tissue.