The most promising tool for future applications in the field of science as well as in medicine is the use of nanobiotechnologies. Especially self-assembly systems with tailored properties on a nanometer level fulfill the requirements to nano-organized systems in a satisfactorily manner. Hence the development of so-called nanocapsules prepared by means of Layer-by-Layer technique was a great progress on the way to individual drug delivery systems or nano-sized bioreactors. The preparation of hollow shells for drug delivery use requires polyelectrolytes as well as a charged core that are not cytotoxic. According to this purpose CaCO3 crystals with different shapes were introduced as removable template for capsules with changeable permeability as a result of pH variations. Due to the low toxic potential of the core it could be valuable for applications in human body.
Furthermore the nano-organized shells are suitable as coating of living cells or artificial tissue. With this “second” cell wall it is possible to target the encapsulated material to predefined organs, and to prevent immune response. Moreover one can choose between the breakage of the coverage using the capsule only as targeted carrier or the production of proteins inside the remaining shell. The requirements for this application are polyelectrolytes that are not toxic to the tissue of the transplantation site as well as to the coated cells.
