Influence of the printing parameters on the properties of Poly(lactic acid) scaffolds obtained by fused deposition modeling 3D printing

Abstract

3D printing techniques are of great interest in the sector of scaffold development aiming for bone tissue regeneration mainly due to the possibility of customizing the scaffold according to the area of the bone defect to be regenerated. Among the 3D printing techniques, the fused deposition modeling (FDM) stands out as promising because it does not require the use of solvents and toxic components throughout the manufacturing process of the scaffold. In this sense, the present article aims to evaluate the influence of the printing speed and the temperature of the printing head on the properties of poly(lactic acid) scaffolds. Three speeds of the printing head (4600 mm/min, 480 mm/min, and 500 mm/min) and two different extrusion temperatures (200oC and 220oC) were evaluated, maintaining the architecture and all other printing conditions constant. After obtaining the scaffolds, they were characterized by the following techniques: Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), time-domain nuclear magnetic resonance (TD-NMR), compressive modulus, L929 cell viability, and enzymatic degradation. The results obtained showed that the increase in printing temperature and speed was able to influence some properties of the material: increase crystallinity, compressive modulus, thermal resistance, and reduce molecular mobility and enzymatic degradation rate of the scaffolds. These findings are promising and indicate that, by altering only the basic parameters of 3D printing, it is possible to modulate the properties of the scaffolds obtained, to achieve greater crystallinity and a superior compressive modulus.