*2.6. In Vivo Xenograft Model and Nanostar Administration*

Female Hsd:Athymic *Nude-Foxn1nu* mice were used (8 weeks, Harlan, Horst, The Netherlands) during these experiments. All animal experiments were approved by the local animal ethics committee of the KU Leuven and were performed according to the national and European regulations. Animals were kept in individually ventilated cages with food and water ad libitum. A total number of <sup>1</sup> <sup>×</sup> <sup>10</sup><sup>7</sup> SKOV3 tumor cells suspended in 100 <sup>μ</sup>L were injected into each hind limb of the mice and left for two weeks to grow into solid tumors [22].

After formation of tumors (size <sup>&</sup>gt; <sup>200</sup> <sup>μ</sup>m3), 100 <sup>μ</sup>L containing 9.2 <sup>×</sup> 1011 NPs/mL were injected into the tumor on the left hind limb. For controls, 100 μL PBS was injected into the right tumor in all animals (sham control). During all imaging experiments, tumor cell and nanostar injections, the animals were anesthetized with 1.5% isoflurane in 100% O2. The body temperature and respiration rate were monitored and maintained at 37 ◦C and 80–120 min<sup>−</sup>1, respectively. For the imaging experiments, three mice were used per condition while for the therapy experiments, six animals were used per condition.
