Implications for the biofunctionalization of drug-eluting devices at the example of a site-selective antibody modification for drug eluting stents

Functionality of implant surfaces is considerably determined by the conformations of immobilized biomolecules adjustable by the applied surface modification approach. Moreover, surface modification of drug eluting systems often needs to be thoroughly optimized with regard to possible drug losses associated with a loss of functionality. Here, we thoroughly investigate biomolecule surface loading, functionality, morphology and stability in dependence of modification conditions at the example of a site-selective immobilization of anti-CD34 antibodies (CD34-Ab) to drug-eluting stents with the aim of providing general information on the biofunctionalization of drug eluting systems. In this context, we demonstrate that the reaction time of biomolecule immobilization defines achievable surface loads but also drug loss. We could moreover show that the used site-selective immobilization procedure elevated the surface functionality considerably in comparison to surfaces modified by random physisorption. Furthermore investigated bionfunctional stability gives important indications for storage conditions of biofunctionalized implants.