The synthesis of novel nanostructured mixed matrix membranes is presented in this contribution. The concept is to embed a liquid in which eventually a carrier can be located, as microscopically small droplets in a polymeric matrix. Preparation of capsules by applying and modifying of traditional encapsulations routes is described in detail and a new method to prepare submicrometer-sized capsules based on interfacial crosslinking or copolymerisation is presented. In the last step, the capsules are embedded in a polymer matrix using a novel film formation technique: the capsules are dispersed in the monomer, which is subsequently polymerised.