Advanced High-Entropy Biomaterials (HEBs)

High-entropy materials (HEMs), characterized by their unique multi-principal elemental compositions (typically five or more elements in near-equiatomic mixing), represent a paradigm-shifting class of substances. This compositional hallmark leads to four core effects, including high-entropy, severe lattice distortion, sluggish diffusion, and the "cocktail effect". These effects collectively endow HEMs with exceptional and tunable properties, such as mechanical strength, catalytic activities, and multi-functionality, which are highly attractive for biomedical applications. The recent exploitation of HEMs in biomedicine has been rapidly expanding, but a comprehensive review that summarizes and highlights these advances and their implications is still lacking. This review commences with a detailed discussion on the fundamental characteristics of high-entropy biomaterials (HEBs), deciphering the interplay between their core effects and key physicochemical properties. We then provide a comprehensive overview of their cutting-edge biomedical applications, spanning bone tissue engineering, vascular stents, tumor therapy, anti-inflammatory treatment, antimicrobial interventions, and biosensing. Finally, we discuss the future challenges and opportunities, emphasizing the importance of biosafety evaluation and the promising integration of computational simulations and artificial intelligence to accelerate the rational design of next-generation HEBs for facilitating clinical translations.