Thiomer coated Nanoparticles

Due to the great progress in biotechnology as well as recombinant technology, a broad variety of therapeutic peptides and proteins can be produced in commercial quantities. Most of these drugs are administered via injections which are associated with inconvenience and low patient compliance. Among the non-invasive administration routes, the oral route is the by far most favored one. Regarding oral peptide/protein delivery it has to be distinguished between two possible targets: firstly, therapeutic peptides/proteins including insulin or calcitonin which are absorbed from the gastro-intestinal tract in order to reach systemic circulation and secondly, antigens for oral vaccination which can induce mucosal as well as systemic immune response via M cells of Peyers patches. In recent years, various approaches have been developed to overcome the barriers related to the oral route of administration. Among the most promising approaches are the thiomer (thiolated polymer) technology and the utilization of micro- and nanoparticulate delivery systems. Both attempts have been proven in several in vitro as well as in vivo studies to be highly effective. Within this project, a combination of these two techniques shall be established. Nanoparticulate systems which are known to protect incorporated drugs and to generally improve oral bioavailability shall be coated with thiomers. Thiomers display up to 100-fold enhanced mucoadhesive properties in comparison to unmodified polymers. Moreover, thiomers inhibit various proteolytic enzymes and efflux pumps and improve peptide permeation across mucosal membranes. Two model drugs, calcitonin and the antigen ovalbumin, shall be used to demonstrate the predominance of the novel delivery systems in comparison to state of the art systems. A successful development of such delivery systems would contribute to make feasible the oral administration of various therapeutic peptides and proteins which are currently administered via the parenteral route.