Multifunctional synthetic materials are nowadays an alternative to autografts and allografts as raw resources for bone reconstruction, a necessary step after traumas or tumor resections leading to a significant bone loss [1]. A surgical intervention being necessary, bacterial infections can occur. This is why the design of multifunctional materials, combining bone regeneration, antibacterial properties and which could in addition allow the destruction of remaining or resurgent cancer cells, is pursued.
 
Multifunctional nanometric heterostructures have been synthesized by soft chemistry. They possess a magnetic core (γ-Fe₂O₃) which can allow cancer treatment through magnetic hyperthermia. This latter is encapsulated in a mesoporous copper-doped bioactive glass (SiO₂-CaO) shell. The mesoporous shell structure is meant to increase the material’s exchange surface with biological fluids, in order to improve its bioactivity [2]. Developed in the 1970s, bioactive glasses are well known to strongly bond in vivo with tissues, thanks to their dissolution mechanism, inducing hydroxyapatite crystal formation at their surface and liberating ions promoting bone regrowth [3]. Copper ions are added to the glass composition to confer antibacterial properties and stimulate angiogenesis upon release after material implantation [4].
 
 In this study, the magnetic cores were synthesized by iron salts co-precipitation and the glass shell was grown using the sol-gel process (modified St?ber method). Playing on different parameters such as calcium nitrate content, surfactant concentration and copper nitrate addition moment allowed to control the final heterostructures size, shape and porosity.
 
The obtained heterostructures were finely characterized (structure, chemical composition, size, surface area) using X-ray diffraction, transmission electron microscopy and N₂-sorptometry. Thereafter, their bioactivity was evaluated after immersion in simulated body fluid at 37°C, through the monitoring of hydroxyapatite crystal formation. Copper ions release kinetic was determined using inductively coupled plasma - optical emission spectroscopy. Finally, the core-shells heating power was measured by calorimetry.
 
All these results confirmed that mesoporous multifunctional bioactive glass nanoparticles are promising to become an additional tool for simultaneous cancer treatment and bone loss repair.