All surgeries carry a risk of bacterial infection. These surgical site infections (SSIs) represent a serious health risk to patients as they can result in increased physiological stress, prolonged hospitalization and an increased chance of morbidity. This is why the BoneFix project will include an antibacterial hydrogel, which will be applied as a top coating over the fixation patch, to protect the patient from surgical site infections. The research team at KTH have recently completed the formulation of this hydrogel, which includes cationically charged dendritic-linear-dendritic polymers. The high concentration of cationic charges on these polymers allows them to kill bacteria by disrupting their negatively charged cell membranes. Importantly, this mode of antibacterial action does not require the use of antibiotics; therefore, the use of these polymers will not contribute to the growing threat of emerging antibiotic resistant bacteria strains.
In addition to cationic charges, the dendritic-linear-dendritic polymers contain allyl functional groups, allowing for their curing with thiol crosslinking polymers through thiol-ene coupling chemistry. The hydrogel solution is simply applied to the top of the fixation patch and cured with the same high-energy visible light emitting lamp that is used to cure the fixation patch and bone scaffold hydrogel technologies of BoneFix. The use of thiol-ene coupling chemistry to cure all three of the BoneFix domains will allow surgeons to efficiently and simply make bone restoration patches without needing to master multiple curing techniques.
The team at KTH looks forward to demonstrating the antibacterial hydrogel together with the other BoneFix domains on various bone fractures later in the project. KTH and the consortium partner Biomedical Bonding AB are also developing prototype product kits for the delivery and application of the hydrogel.