Nanoparticles are generally defined as particles with a diameter in the nanometre size range; enabling to directly interface with life at the subcellular scale. In this context, the University of Namur has investigated the great potential of hybrid (organic shell – inorganic core) gold nanoparticles (AuNP) as platforms for cancer theranostics, being able to act both as agents for radiation therapy and diagnostic imaging [1,2]. Indeed, gold particles have emerged as promising radiosensitizers achieving significantly elevated radiation dose upon irradiation, thus increasing the effectiveness of radiation therapy. By decorating the gold nanoparticles through an organic polymer coating strategy with antibodies (mAb) that target the tumor cells, the radiosensitizing effect is focussed to the tumor and not to normal tissues. In addition, targeted gold nanoparticles can serve as imaging contrast agents supporting better tumor localisation and thus improving treatment accuracy.
Preliminary tests at the University of Namur with the AuNP-mAb are encouraging: the nanoparticles are stable and keep the faculty to target the cancer specific antigens in vitro and in vivo. However, the standards associated to the use of nanoparticles in medicine have become increasingly stringent. This imposes us to have a deep understanding of cytotoxicity of nanohybrids on the normal tissue prior to any use.
In addition, to further increase the theranostic applications, the suitability of such AuNP-mAb as a platform for delivery of medical radionuclides to tumor cells has to be tested. In particular, it is interesting to verify the effectiveness of radionuclide-doping of AuNP (leaching, transport and irradiation of healthy tissue have to be prevented) and of dose delivery. Moreover, the potential synergetic effect of the ionizing radiation emitted by the radionuclide and the AuNP radiosensitizing needs to be verified.
 Gontard et al 2014, Transmission electron microscopy of unstained hybrid Aunanoparticles capped with PPAA (plasma-poly-allylamine):Structure and electron irradiation effects, Micron 67 (2014) 1–9  Peglow et al 2015, Plasma-vapour-deposition synthesis of Au, Ag and AuAg core-shell nanoparticle on metal oxide semiconductors, 22nd International Symposium on Plasma Chemistry, July 5-10, 2015; Antwerp, Belgium