Nanoparticles possess unique properties originating from their small size that have caused an increasing interest for their use in various applications. New fields of applications can be explored based on these exceptional features. The fabrication processes greatly influence the resulting product characteristics and allow for the preparation of highly defined metal oxide nanoparticles. Depending on the intended application, the preparation of nano- or microstructures with defined characteristics including their morphology and composition may be required to enhance the stability or ensure the desired function by possibly combining different materials. Various techniques for both synthesis and structuring are available that can be controlled by the tuning of process and formulation parameters. In the course of this scientific thesis, tailored microstructures of functional metal oxide nanoparticles were prepared for the use in target applications, that exploit specific properties of the utilized particle system. Superparamagnetic iron oxide nanoparticles (SPIONs) were prepared and subsequently functionalized with a tailored affinity ligand according to a previously established sol-gel synthesis and reaction process, respectively. The functionalized nanoparticles were then utilized for the magnetic particle-based separation of the recombinant model protein A in shake flask cultivation experiments. Furthermore, the aggregation of as-prepared SPIONs via spray drying was examined under variation of process and formulation parameters to improve the magnetic separation characteristics. These newly developed aggregates were then also functionalized and evaluated with regards to their applicability for the protein purification. Here, a scale up of the bioreactor system was conducted and the successful separation of two model products, Protein A and an antibody fragment, was demonstrated. Furthermore, the synthesis of lithium niobate nanoparticles LiNbO3 via the nonaqueous sol-gel route was established. A thorough investigation of the influence of both process parameters (synthesis temperature, reaction time, and precursor pretreatment) and formulation parameters (precursor composition, solvent, precursor purity and concentration) on the resulting nanoparticles was performed. Special focus was on the crystallinity of the obtained product. Moreover, different strategies for the post-synthetic stabilization were studied. Starting from the previous findings, the modification of cathode active material particles for lithium ion batteries with the prepared LiNbO3 nanoparticles using different coating methods (in situ synthesis, dry mixing, and suspension coating) was evaluated. Finally, an initial analysis of the electrochemical properties of the resulting coated materials was performed and the general feasibility was shown with a proof of concept.weiterlesen