Manganese‐Doped Mesoporous Bioactive Glasses

ABSTRACT

Bioactive glasses have emerged as promising biomaterials due to their ability to promote osseointegration and accelerate bone regeneration. This study investigates the formulation and characterization of manganese (Mn)‐doped 85S mesoporous bioactive glass (85SiO ₂ –(15 −  x )CaO– x MnO mol%, x  = 1, 2, 3, and 4). Morphological and structural analyses confirmed the amorphous and mesoporous structure of the microsized glass particles, showing average pore sizes of 2 nm. Bioactivity was evaluated in vitro in simulated body fluid (SBF), demonstrating the formation of a hydroxycarbonate apatite (HCA) layer on the surfaces, as evidenced by x‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cytotoxicity was assessed in vitro using the MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) assay, revealing that Mn‐doped glasses exhibited no significant cytotoxicity, indicating biocompatibility. Antimicrobial and antifungal properties were also evaluated. The results indicate a composition‐dependent effect of Mn, with 0–2 mol% Mn preserving mesoporosity, sustaining rapid HCA formation, and ensuring cytocompatibility. Within this range, particularly at 2 mol% Mn, the glasses exhibit enhanced antibacterial activity against selected strains, whereas strong antifungal effects are mainly associated with undoped 85S and 1 mol% Mn. In contrast, higher Mn contents (3–4 mol%) reduce specific surface area, delay or suppress HCA formation, and do not provide superior antimicrobial performance. Altogether, these findings define 1–2 mol% Mn as an optimal doping window, highlighting the trade‐off among structural features, bioactivity, and antimicrobial efficacy.