The expertise, resources and specific knowledge of all participating parties will be combined to achieve a breakthrough in design, synthesis and application of peptide analogues (peptidomimetics) possessing photo-controlled biological activities, with special emphasis on anti-microbial and anti-cancer activities. The main idea behind the Project consists in chemical incorporation of artificial photo-controllable building blocks into known biologically active peptides by replacing their natural building blocks – the amino acid residues. Such a modification would provide photocontrolled peptidomimetics which can reversibly change their structure between two different photo-forms upon irradiation with light of different wavelength. The participating parties possess general know-how for design of the peptidomimetics which can exist in two photo-forms, biologically active and inactive ones, reversibly interconvertible by light of different wavelength. This opens a possibility to convert inactive peptidomimetics to active compounds by irradiation with physiologically benign light directly in tissues with very high spatiotemporal precision and can be a fundamental basis of new therapeutic strategies. The research staff exchange and other activities planned under the Project will be dedicated to accomplish four complementary work packages: (i) carrying out pharmacokinetic and toxicity studies of the photocontrolled peptidomimetics synthesized by the parties previously; (ii) evaluation of novel photocontrolled building block chemotypes for their compatibility with peptides; (iii) creation of new photocontrolled peptidomimetics, especially based on the novel building blocks and the know-how developed by the parties (e.g. using “stapled peptides” technology); (iv) multidisciplinary training of the researchers whose future work will be aimed at further development of the most advanced photocontrolled peptidomimetics as drugs suitable for photodynamic therapy.