Traditional treatments for bone deformities coming from ailments such as trauma (fractures) or osteoporosis can be fruitless, especially if there is infection. To overcome this insufficiency, researchers have developed the mesoporous bioactive glass (MBG) nanoparticles that contain copper and take a multifunctional role. The MBGs boost new bone growth, have an antibacterial effect and can urge the formation of blood vessels, all at the same time.
Vitale-Brovarone, a researcher at Politecnico di Torino, said that that was the first study using the ultrasound-assisted sol-gel method to produce MBG nanoparticles containing copper ions. The method relies on a template agent to assemble a regular nanoporous structure in the bioactive glass. There is also the possibility to vary the copper content, surface area, nanopore size, the release of the copper ions and glass composition in order to obtain a better biological response.
According to Vitale-Brovarone, Copper-MBG nanoparticles and their ionic dissolution extracts exhibited important antibacterial effect against three different bacteria strains, Escherichia coli, Staphylococcus aureus and Staphylococcus epidermidis, and the ability to inhibit and disperse the biofilm produced by bacteria. Biofilms can be particularly resilient to antibiotics, which makes the MBG nanoparticles really attractive in their ability to neutralize them. Vitale-Brovarone adds that MBG nanoparticles were versatile, characterized by multifunctional biological properties and drug-loading ability in comparison to scaffolds based on MBGs, whose application were limited by the poor mechanical properties of the final meso-macroporous structure.
The MBG nanoparticles can be coated with stimuli responsive agents and put on directly on the site of damage or infection. In a different way, nanoparticles could be dispersed in an organic matrix and implanted into the body to produce collagen-based compounds that stimulate bone repair.
Different ions could also be introduced into the MBG composite to improve osteostimulation (bone growth) and reduce the activity of osteoclasts related to osteoporosis. Still the main challenge for perfect tuning of the ion release kinetics to match clinical needs such as time of the delivery and concentrations remains, said Fiorilli, another researcher at Politecnico di Torino.