In order to overcome the shortcomings of the commonly prescribed antibiotics in the treatment of infections caused by implanted biomaterials, the researchers devised an external magnetic field to guide the mentioned nanoparticles towards the grown bacterial colonies through a targeted drug delivery approach. By doing so, a multiple-fold higher antibacterial activity, compared with gentamicin, was achieved.
“As the initial part of our research, we carried out a feasibility study on the use of SPOINs (superparamagnetic iron oxide nanoparticles) as bactericide agents. The idea was triggered by the fact that most of metal nanoparticles exhibit antibacterial characteristics. Although their applicability is hindered by their potential toxicities, SPOINs are found to kill only the bacteria and being harmless to human body cells,” Dr. Shahriar Sharifi, member of the research group, explained.
“Bearing the special magnetic properties of the SPOINs in mind, we tried to direct these nanoparticles to the locations of the bacterial colonies by exerting an external magnetic field. In this way, we came up with considerably increased and deeper penetration of the nanoparticles into the formed biofilms. These diffused SPOINs later generate reactive oxygen species (ROS), thanks to their nanometric dimensions as small as 5 nm, which damage the bacterial cell walls resulting in their death.” Dr. Sharifi said, explaining about the mechanism of antibacterial activity of the SPIONs.