Implant coatings for intentional implant removal

Implant removal is often the last resort in cases of untreatable persistent infections or mechanical failure of the implant. In the case of cochlear implants, removal of the implant may also be necessary in order to replace it with a technically improved version. Since the basic aim is to achieve a good integration of the implants, which often also causes the surrounding tissue to grow, implant removal in many cases leads to severe tissue damage. This damage can subsequently have a negative effect on the healing and also the function of the newly inserted implant. The aim of subproject B08 is to develop implant coatings that enable gentle removal of the implant despite primarily firm tissue integration. The challenge here is that the coated implant must initially have good healing and stability, but the implant removal should be facilitated by weakening the anchorage with the surrounding tissue through a trigger.

Various concepts are being researched for the production of coatings that enable the targeted loosening of implants through a material modification. Polymer nanoparticle nanocomposites are used for the coating materials. Hyperthermia by magnetic heating of superparamagnetic nanoparticles or light-induced breaking of bonds are used as triggers. The breaking of nanoparticle-mediated adhesion between polymer and tissue (concept 1), the breaking of chemical bonds between nanoparticles and polymer strands (concept 2), or within nanoparticles (concept 3) should lead to a softening of the nanocomposite, which will then facilitate removal. The project focuses on the chemical synthesis of special polymers and nanoparticles and the production of nanocomposites that can fulfil this task.