Magnesium-reinforced PMMA composite scaffolds: Synthesis, characterization, and 3D printing via stereolithography

Metal particle-reinforced polymer resin scaffolds are becoming increasingly prominent in biomedical applications due to their potential to support tissue regeneration and healing. These scaffolds are designed to serve as temporary frameworks that support affected tissues and gradually degrade during healing. The primary focus of these research efforts has been on determining the optimal materials and methods for creating these scaffolds, ensuring that they are biocompatible, capable of withstanding structural strains, and can support cellular proliferation, tissue growth, and vascularization. Despite the growing interest in polymers and their metal composites, a notable gap exists in leveraging the benefits of fabricating these composites through additive manufacturing techniques, particularly stereolithography (SLA). Magnesium (Mg), in particular, is a biocompatible and osteoconductive material known for its remarkable mechanical properties and biodegradability, making it highly suitable for bone implants. Additionally, Mg can potentially regenerate skin tissues and inhibit bacterial infections. Mg ions are crucial for wound healing because they repair the skin barrier and facilitate blood coagulation. This research focuses on finding optimal conditions for manufacturing magnesium-induced poly(methyl methacrylate) (PMMA) resin scaffolds using SLA. To evaluate their printability and the effect of different material compositions on the 3D-printed structures, PMMA resin was mixed with high-weight percentages (wt%) of Mg alloy WE43. This mixture was then used to 3D-print test coupons and scaffolds via SLA. The impact of Mg incorporation on the scaffold's structural integrity, thermal degradation, and biological response was assessed through physicochemical and thermal characterization and biocompatibility experiments. Notably, pure PMMA exhibited the highest tensile strength, 26.23 ± 0.14 MPa and an elastic modulus of 707.81 MPa, while PMMA resin/1% Mg showed the lowest strength (19.46 ± 0.25 MPa) and modulus (392.88 MPa), indicating a decrease in mechanical integrity with higher Mg content. However, the thermal stability was enhanced with the addition of Mg as the thermal degradation onset improved from ∼310 to 335°C. The challenges encountered in manufacturing PMMA resin/Mg composites and their potential applications were discussed, highlighting the future directions and promising avenues for further research and development.