Eisen-Nanopartikel dämmen Tumorwachstum ein
Das intravenöse Eisenpräparat Ferumoxytol und andere Eisenoxid-Nanopartikel werden als Nahrungsergänzungsmittel, Kontrastmittel für Magnetresonanztomographie und als Wirkstoffträger in Medikamenten genutzt. In einer neuen Studie zeigen Forscher der Universität Stanford zum ersten Mal einen intrinsischen therapeutischen Effekt von Ferumoxytol auf frühen Brustkrebs sowie Lungenkrebs Metastasen in der Leber und der Lunge.
The researchers showed that ferumoxytol can activate the immune system to attack cancer cells. The data has broad implications for diagnostic and therapeutic nanoparticle applications. Since ferumoxytol is FDA-approved for intravenous treatment of iron deficiency, it could be applied 'off label' to protect the liver in patients from metastatic seeds and potentiate TAMs-modulating cancer immunotherapies. Conversely, in this new study, the scientists observed an intrinsic therapeutic effect of iron oxide nanoparticles themselves. The proposed approach to suppress liver metastases by repetitive systemic ferumoxytol administrations should be achievable without significant impact on iron load or liver toxicity. Due to the large surface area and chemically defined surface structure, iron oxide nanoparticles such as ferumoxytol can be conjugated or functionalized to numerous ancillary molecules to further amplify the desired immune-modulating properties. The scientists explain that ferumoxytol could be locally delivered to unresectable tumours via interventional procedures, to micrometastases in confined spaces – e.g. peritoneal seeds. Or to tumour resection margins at the end of a tumour surgery with positive resection margins, in order to induce a pro-inflammatory reaction against cancer cells and suppress tumour growth in the interval between a tumour surgery and initiation of postsurgical chemotherapy or irradiation. On the other hand, patients with primary tumours that typically metastasize to the liver could receive protective ferumoxytol medications to prevent early metastatic seeds. In the next stage of their study, the researchers will be more focused on the evaluations of nanoparticle-drug combinations. Potential clinical applications of ferumoxytol-mediated pro-inflammatory immune responses could entail potentiating the efficacy of other M1-activating cancer immunotherapies, such as anti-CD47 mAbs or antibodies blocking IL-4 or IL-13 signalling.
Quelle: Nanowerk
Bildquelle: Fotolia