This article describes the preparation and the physico-chemical characterization of a new host-guest system consisting of zeolite beta nanoparticles as host and mitoxantrone as guest. The resulting host-guest system mitoxantrone@beta is characterized in terms of morphology (transmission electron microscopy, dynamic light scattering), structure (powder wide-angle X-ray diffraction, nitrogen sorption), surface charge (xi-potential measurements), and optical properties (UV-visible absorption, steady-state fluorescence). Mitoxantrone@beta particles are monodisperse in size with a mean diameter centered around 100 nm. Mitoxantrone guest molecules are adsorbed at the micropore entrances of zeolite host. Resulting nanoparticles retrieve the interesting optical properties of guest molecules with a fluorescence emission band in the near-infrared region. Mitoxantrone loading is comparatively evaluated by three different means (elemental analysis, direct and indirect UV-visible absorption studies) showing a loading level of 6.8 mu mol/g. Mitoxantrone@beta nanoparticles also show a noticeable cytotoxic effect when applied to cancer cells. (C) 2011 Elsevier Inc. All rights reserved.