Incorporation of Selenium into Sol–Gel‐Derived Bioactive Glass: Influence on Glass Structure, Bioactivity, and its Selective Cytotoxicity

Selenium (Se) is an essential trace element with antioxidant, anti‐inflammatory, and anticancer properties, as well as its role in skeletal development, which has led to increased interest in Se‐releasing bioactive glasses (BGs). However, the relationships among Se incorporation, glass network structure, ion release behavior, and cytotoxic Se concentration levels remain insufficiently understood. Here, a selenium‐containing bioactive glass derived from the 58S composition (60SiO 2 ‐36CaO‐4P 2 O 5 , mol%) was synthesized via the sol–gel route, yielding porous, amorphous materials with specific surface areas ranging from 70.6 to 127.8 m 2 g −1 . X‐ray photoelectron spectroscopy revealed that Se is predominantly present as Se 4+ species, acting primarily as a network modifier and leading to a less polymerized silicate network. Glasses exhibited sustained Se release (up to 16 ppm) in simulated body fluid and evidence of hydroxycarbonate apatite layer formation. Cell viability evaluation demonstrated dose (100–800 µg mL −1 ) and time (24, 48, and 72 h) dependent cytotoxicity toward Saos‐2 osteosarcoma cells, while maintaining the viability of MC3T3‐E1 pre‐osteoblastic cells, with Se levels between 1.3 and 2.6 ppm providing a balance between osteoblast tolerance and inhibition of osteosarcoma cell proliferation. The findings highlight the potential of Se‐doped 58S BGs for applications in bone tissue engineering.