Effects of ultrasonic vibration on 3D printing of polylactic acid/akermanite nanocomposite scaffolds

The mechanical properties of 3D-printed scaffolds for load-bearing implantation are crucial. Although the addition of nanoparticles to polymeric scaffolds can improve their mechanical and biological properties, due to certain limitations in printability, high amounts of reinforcement cannot be used. Therefore, in this study, an attempt was made to use ultrasonic vibration to inhibit nozzle clogging during fused filament fabrication (FFF) of polylactic acid (PLA) scaffolds containing 0, 20, and 40 wt% akermanite (Ak). Nozzle clogging happened during the conventional 3D printing of PLA-40 wt%Ak, while that did not occur during ultrasonic-assisted 3D printing of PLA-40 wt%Ak. Results of X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) indicated that applying ultrasonic vibration had no negative effect on the phases and morphology of the scaffolds. The results obtained by the compression test indicated that applying ultrasonic during 3D printing resulted in almost 27 % increment of elastic modulus and almost 25 % increase of the compressive strength of the scaffolds. As the conclusion, this study highlights the effectiveness of ultrasonic-assisted 3D printing in producing nanocomposite scaffolds with significantly higher nanoparticle loadings, as compared to conventional printing methods. By utilizing ultrasonic vibration during the printing process, the study showcases the possibility of overcoming viscosity limitations and optimizing the mechanical performance of scaffolds for various biomedical applications, including bone tissue engineering.