Recent Advances in Metal Particle Reinforced Polylactic Acid Biocomposites via Additive Manufacturing for Biomedical Applications

Abstract

Polylactic acid (PLA) has attracted significant attention in biomedical applications due to its biodegradability, biocompatibility, and ease of processing; however, its poor mechanical properties, low toughness, and limited suitability for load-bearing applications significantly restrict its broader clinical use. The primary challenges hindering the development of high-performance PLA-based biocomposites are insufficient interfacial bonding between the polymer matrix and metal reinforcements, non-homogeneous dispersion of metallic phases, and unpredictable degradation behaviors within physiological environments. This study comprehensively explores the advancements in PLA based metal-reinforced biocomposites manufactured through additive manufacturing techniques, specifically focusing on enhanced mechanical properties and biocompatibility. The integration of metallic reinforcements, including titanium, stainless steel, magnesium, and silver, into PLA matrices significantly improves tensile strength, durability, and overall mechanical performance. Material Extrusion (ME) technology emerges as a pivotal manufacturing method, enabling the fabrication of complex, customized geometries essential for biomedical applications. The research systematically evaluates the optimization of metal reinforcement ratios and their effects on the viscosity, moldability, mechanical robustness, and biocompatibility characteristics of the resulting biocomposites. The study reveals that while certain metals enhance mechanical properties, others contribute antimicrobial properties and improved bioactivity, making these composites particularly suitable for tissue engineering applications. However, challenges persist in achieving uniform metal distribution, ensuring adequate metal-polymer interfacial adhesion, and controlling biodegradation rates. This review bridges existing literature gaps by providing a holistic perspective on how PLA-based metal-reinforced biocomposites can meet both mechanical and biological requirements, advancing their potential applications in the biomedical field, particularly for personalized implants and scaffolds in tissue engineering.