The main activity in this laboratory is the development of bioconjugates for targeted tumour therapy. Targeted cancer chemotherapy is one of the most promising approaches to increase the selectivity and to decrease the toxicity of chemotherapeutic agents. For this purpose, cytostatic drugs are attached to peptides recognized by receptors that are highly expressed on tumour cells compared to normal tissues. In our laboratory targeting peptides are prepared by solid phase peptide synthesis and the drug molecules are attached directly or through a cleavable linker to them in solution using chemoselective ligation procedures. The synthesis of drug - peptide bioconjugates needs complex combination of peptide and organic chemistry.