Rare earth-doped bioactive glasses (REBGs) have emerged as a significant area of research in biomaterials due to their unique properties and therapeutic potential. These advanced materials combine the bioactive characteristics of traditional bioactive glasses with the distinctive features imparted by rare earth elements, particularly cerium (Ce), neodymium (Nd), erbium (Er), and ytterbium (Yb). These rare earth elements are notable for their multifaceted roles in enhancing the mechanical strength and bioactivity of glass matrices. Their incorporation into bioactive glasses has been shown to improve osteoconductivity and stimulate the osteogenic differentiation of mesenchymal stem cells. Furthermore, they exhibit antimicrobial properties, which are crucial for reducing infection rates in orthopedic applications. Additionally, their presence enhances optical properties and facilitates non-invasive imaging techniques for monitoring tissue integration and healing processes. This review examines the mechanisms through which rare earth ions influence the glass network structure and enhance ion release profiles, thereby contributing to improved bioactivity. It also explores the potential of REBGs in targeted drug delivery systems is explored, highlighting their capacity to release therapeutic agents in a controlled manner. The underlying mechanisms of bioactivity in REBGs are discussed, with particular focus on the formation of hydroxyapatite (HA) upon immersion in simulated body fluid (SBF). The roles of rare earth elements in promoting HA nucleation and growth are analyzed, along with their effects on cellular interactions, including osteoblast adhesion, proliferation, and differentiation. In terms of therapeutic applications, this review emphasizes the potential of REBGs in bone regeneration. The synergistic effects of REBGs in enhancing both the mechanical and biological performance of bioactive glasses are highlighted, supported by in vitro and in vivo studies validating their efficacy. By synthesizing current knowledge on the properties and applications of REBGs, this review aims to pave the way for future research in this promising field. Opportunities for further optimization of synthesis techniques, exploration of additional rare earth elements, and the development of multifunctional bioactive glasses are also discussed, providing a roadmap for advancing biomaterials science in regenerative medicine. • Rare-earth doping (Ce, Nd, Er, Yb) in bioactive glasses — structure and bioactivity. • RE ions modulate glass network, ion release, and hydroxyapatite formation. • Enhanced osteogenesis, angiogenesis, and bone regeneration potential. • Antioxidant, antimicrobial, photothermal, and luminescent therapeutic functions. • Analyze dopant concentration limits to ensure cytocompatibility and safety.
Moghanian et al. (2026) studied this question.