The goal of this study is to prepare novel hybrid nanoparticles, in the form of micellar nanoparticles in aqueous media, which will combine the properties of the amphiphilic diblock copolymers (such as PEO-b-PPhOx and PI-b-PEO) with the ones of the nickel 1,2-dithiolene (1,2-Ni DT) complexes. The structural and morphological analysis of these nanoparticles have revealed that they can be promising for photodynamic therapy and near-infrared (NIR) optical imaging due to their size and absorption in NIR. The micellar nanoparticles have been studied not only in aqueous solutions but also under other physiological conditions, that is, PBS and PBS-FBS buffer solutions. Their solutions are characterized by several methods, including UV-vis spectroscopy, light scattering, and FTIR. (c) 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2507-2513