De novo protein design is one of the most difficult and fascinating problems in chemistry. Our approach to this question is based on peptide dendrimers as synthetic artificial proteins. A combinatorial synthesis protocol allows us to prepare and test over 60'000 different peptide dendrimers in a single experiment, which has opened the door to peptide dendrimers with selective binding affinities to small molecules such as vitamin B12, and to proteins such as lectins using glycosylated dendrimers. The present research project is dedicated to the development of peptide dendrimers with diverse functions considering fundmental aspects of structural design as well as their biomedical applications. Ongoing projects concern molelcular dynamics studies of catalytic peptide dendrimers, the study of peptide dendrimers containing secondary structure elements, a study of vitamin B12-binding peptide dendrimers, an investigation of the proteolytic stability and immunogenicity of peptide dendrimers, and the development of glycopeptide dendrimers for drug delivery and as antimicrobial agents.