Sol-gel synthesis and characterization of novel cobalt ions-containing mesoporous bioactive glass nanospheres as hypoxia and ferroptosis-inducing nanotherapeutics

Herein, novel Co2+ ions-containing mesoporous bioactive glass nanospheres (Co-BGn) with low and high cobalt contents were prepared by a facile one-pot ultrasonic-coupled sol-gel synthesis. Structural evaluations revealed that Co-BGn are totally amorphous and cobalt ions exist as Co2+ ions in the glass structure. Notably, Co-BGn exhibited uniform spherical morphology, nanosize (< 100 nm), high worm-like mesoporosity (0.41 cm(3)/g) and large specific surface area ca. 787.5 m(2)/g. Interestingly, low and high Co-BGn showed sustained release of Co2+ ions with controlled release (8 - 32 ppm) and fast release (54 - 112.5 ppm) kinetics over 2 weeks, respectively. Furthermore, Co-BGn showed good bone-like hydroxyapatite formation in vitro. Accordingly, low Co-BGn with controlled release of Co2+ ions can be considered as hypoxia-mimic nanotherapeutics for bone/skin tissue regeneration. Whereas, high Co-BGn with fast release of high concentrations of Co2+ ions can be considered for ferroptosis killing of cancer cells including bone and skin cancers.