The main goal of the current project is to develop targeted nanoparticle mediated delivery of nucleic acids for in vivo applications crossing the endothelial barrier and avoiding immunogenic recognition. Therefore, the preparation of mRNA loaded nanoparticles and the characterization thereof regarding physico-chemical and biological aspects will be realized. The particles will be tested in an advanced cell culture setup using a fluidic approach combined with co-cultivation. Different aspects, such as cellular targeting and uptake of nanoparticles, endosomal release and intercellular delivery of mRNA as well as efficiency of nanoparticle mediated gene delivery will be addressed. Design parameters like size, surface charge, particle density, and the balance between active and passive targeting will be investigated within the project.