Two-dimensional (2D) nanoparticles are becoming increasingly important, particularly in areas such as catalysis, optoelectronics and biomedicine. An international research team has now developed a new strategy for producing nanoparticles with defined properties by ‘living’ crystallization-driven self-assembly (CDSA). Versatile structures for medical applicationsThis process was used to create highly precise nanoparticles with a segmented chemical structure. A comprehensive study of biocompatibility showed that PDTC nanoparticles exhibit no detectable cytotoxicity towards healthy and cancerous cell lines. These findings could pave the way for innovative medical applications, including targeted drug delivery and biocompatible carrier systems.