Titanium-Based High-Entropy Alloys for Biomedical Applications: Recent Progress and Future Prospects

Titanium-based biomedical high-entropy alloys (Ti-HEAs) have recently emerged as a promising class of metallic biomaterials engineered to overcome the limitations of conventional implant alloys. Traditional materials often exhibit mismatched elastic modulus, inadequate corrosion and wear resistance, and limited biocompatibility in complex physiological environments. Ti-HEAs address these challenges through multi-principal element design, enabling tailored combinations that achieve a low elastic modulus, high yield strength, and superior wear and corrosion resistance. Recent studies demonstrate that incorporating biocompatible elements such as Ti, Zr, Nb, and Ta significantly reduces ion release, enhances mechanical stability, and improves cellular response and osseointegration. This review highlights key advancements in composition design, microstructural control, and the mechanical, tribological, and biological performance of Ti-HEAs, while identifying persistent limitations such as fabrication complexity, high production cost, and limited long-term in vivo data. Emerging directions, including data-driven alloy design, offer pathways to overcome current barriers and accelerate clinical translation. Thus, Ti-HEAs provide a transformative platform for next-generation medical implants with improved durability, biocompatibility, and functional performance.