The invention concerns a complex for delivering light-activated antimicrobial agents (photosensitising (PS) agents) into cells； use of said complex as a medicament in photodynamic therapy； use of said complex for treatment of a microbial infection； a method for the manufacture of a composition comprising said complex； a pharmaceutical or veterinary composition comprising said complex； a combination therapeutic comprising said complex and at least one other agent； a method of treatment employing the use of said complex, composition or combination therapeutic. The complex comprises a poly-ß-amino ester and a photosensitizing agent.
