Colloidosomes: Nanoparticle-Assembled Microcapsules with Selective Permeability

• Applicant: Privatdozent Dr. Michael Maas
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 230456922

The goal of this research project is the preparation of stable colloidosomes with selective permeability for the controlled release of molecules. Colloidosomes are microcapsules that consist of a shell of nanoparticles. The advantages of colloidosomes over other microcapsules (e.g. based on polymers) are their easily tunable porosity and the promising potential to fabricate colloidosomes from many different types of nanoparticles.The colloidosomes that are prepared in this project are to be loaded with different molecules that are examples for different classes of active agents (e.g. standard proteins, antibodies, small molecules). Furthermore, the release of these molecules from the colloidosomes will be studied. Accordingly, the project is comprised of three parts:The first part of the project focuses on the preparation of the colloidosomes. Colloidosome preparation is based on specific interactions between nanoparticles and lipids during the formation of thin films at the interfaces of emulsion droplets. Interfacial shear rheology will be predominately used to characterize the interactions between nanoparticles and lipids in the respective thin films. Through a better grasp of the formation of multicomponent films in emulsions and on planar interfaces we want to produce stable microcapsules without the help of further additives like polymers. On the basis of these insights, it is possible to derive design rules for the preparation of stable colloidosomes from a library of nanoparticles and lipids.In the second part of the project, molecules are loaded into the colloidosomes. Molecule loading and colloidosome preparation can proceed simultaneously. Since the molecules are present during capsule formation, the influence of the molecules on thin film formation, emulsion stability and all other aspects of colloidosome preparation needs to be studied. Again, interfacial shear rheology is the most important characterization method in this part of the project. As could be demonstrated in our preliminary research, loading of the colloidosomes cannot be understood separately from capsule formation and has to be studied as a whole.In the third part of the project, the release of the molecules from the colloidosomes will be studied. The release rate is an important feature of the colloidosomes. It is based on the interactions between the different components (nanoparticles, lipids, molecules) and the pore size. New insights from the release studies can be directly evaluated in light of the design-rules that have been established in the preceding parts of the project.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr.-Ing. Kurosch Rezwan