Borges Roger, Mendonça-Ferreira Leticie, Rettori Carlos, Pereira Isis S O, Baino Francesco, Marchi Juliana
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados 5001 - Bangu, Santo André, SP 08210-180, Brazil.
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Avenida dos Estados 5001 - Bangu, Santo André, SP 08210-180, Brazil; Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Rua Sérgio Buarque de Holanda, 777 - Cidade Universitária, Campinas, SP 13083-859, Brazil.
Mater Sci Eng C Mater Biol Appl. 2021 Jan;120:111692. doi: 10.1016/j.msec.2020.111692. Epub 2020 Nov 4.
Although the three main phases of iron oxide - hematite, maghemite, and magnetite - exhibit superparamagnetic properties at the nanoscale, only maghemite and magnetite phases have been explored in magnetic bioactive glass-ceramics aimed at applications in cancer treatment by hyperthermia. In this work, it is reported for the first time the superparamagnetic properties of hematite nanocrystals grown in a 58S bioactive glass matrix derived from sol-gel synthesis. The glass-ceramics are based on the (100-x)(58SiO-33CaO-9PO)-xFeO system (x = 10, 20 and 30 wt%). A thermal treatment leads to the growth of hematite (α-FeO) nanocrystals, conferring superparamagnetic properties to the glass-ceramics, which is enough to produce heat under an external alternating magnetic field. Besides, the crystallization does not inhibit materials bioactivity, evidenced by the formation of calcium phosphate onto the glass-ceramic surface upon soaking in simulated body fluid. Moreover, their cytotoxicity is similar to other magnetic bioactive glass-ceramics reported in the literature. Finally, these results suggest that hematite nanocrystals' superparamagnetic properties may be explored in multifunctional glass-ceramics applied in bone cancer treatment by hyperthermia allied to bone regeneration.
尽管氧化铁的三个主要相——赤铁矿、磁赤铁矿和磁铁矿——在纳米尺度上表现出超顺磁性，但在旨在通过热疗用于癌症治疗的磁性生物活性玻璃陶瓷中，仅对磁赤铁矿和磁铁矿相进行了探索。在这项工作中，首次报道了通过溶胶-凝胶合成法在58S生物活性玻璃基体中生长的赤铁矿纳米晶体的超顺磁性。该玻璃陶瓷基于(100-x)(58SiO-33CaO-9PO)-xFeO体系(x = 10、20和30 wt%)。热处理导致赤铁矿(α-FeO)纳米晶体生长，赋予玻璃陶瓷超顺磁性，这足以在外部交变磁场下产生热量。此外，结晶并不抑制材料的生物活性，这通过将玻璃陶瓷浸泡在模拟体液中后其表面形成磷酸钙得到证明。而且，它们的细胞毒性与文献中报道的其他磁性生物活性玻璃陶瓷相似。最后，这些结果表明，在与骨再生联合用于骨癌热疗的多功能玻璃陶瓷中，可以探索赤铁矿纳米晶体的超顺磁性。
