Degradation assessment of Mg-Incorporated 3D printed PLA scaffolds for biomedical applications

Abstract

Polylactic acid (PLA)/Magnesium (Mg)-based composites exhibit great potential for applications in bone regeneration and tissue engineering. PLA is a biodegradable and biocompatible polymer, that has the ability to be easily shaped into diverse structures like scaffolds, films, and fibers. However, its inherent low biodegradability limits its applicability for tissue engineering. On the other hand, magnesium, a biocompatible metal known for its good biodegradability and osteoconductivity, is well-suited for bone tissue engineering. In this study, we fabricated and characterized a composite material of Mg/PLA with 5, 10, and 15 wt%Mg alloy (AZ61), which was subsequently 3D printed. The incorporation of Mg particles into PLA matrix offers a solution to overcome the low biodegradation limitations typically associated with the PLA. Moreover, it helps counteract the negative consequences related to the rapid degradation of Mg, such as alkalinization and excessive release of H₂. Additionally, the change in pH values and changes in mass during in vitro degradation indicated that the addition of Mg effectively counteracted the acidic byproducts generated by PLA. Furthermore, X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy were utilized to investigate the degradation of the scaffolds, while thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to compare and contrast the thermal properties of the composites. Our findings demonstrate that the addition of Mg significantly influences the thermal properties of PLA and notably accelerates its degradation, in addition to its noticeable influence on cell adhesion.