The design and fabrication of biocompatible carrier systems for RNA based medicine and therapeutic antibodies equipped with multiple functions suitable for controlled and targeted delivery is the main scope of this proposal. General strategies for the encapsulation and release of RNA and proteins will be developed on the basis of the Layer by Layer technique (LBL) employing core materials tailored to the physico-chemical properties of the respective medications. Alternatively, RNA and antibodies can be also assembled between polyelectrolyte layers. The multilayers will progressive degrade in extracellular media or after being uptake in cells. The progressive degradation of the multilayer will provide a sustainable delivery of the therapeutic agent. The LBL provides also the means to modify the surface of the carrier to increase circulation or to increase specific uptake, according to the intended therapeutic action. To fulfil this aim biocompatible lipid layers will be engineered onto the surface of the carriers. This lipid coat is furthermore the matrix for the incorporation of targeting functions. The encapsulation of therapeutic antibodies, besides its very general importance, specifically addresses ocular applications, to meet urgent delivery problems. The design of a RNA carriers intended for silencing specific genes addresses a rather challenging problem of delivery. Its solution may help to pave the way for the application of the powerful RNA tools as therapeutic agents. The processing and distribution, in vitro and in vivo, of these carriers will be intensively studied. A comprehensive knowledge of how these processes take place will be paramount for the improvement of the coatings and to enhance their performance. Cyitotoxicity of carriers will also be studied.