Magnetic hyperthermia – high therapeutic efficiency of superparamagentic iron oxide nanoparticles in cancer xenograft models

Zielsetzung:

Magnetic fluid hyperthermia (MFH) is a promising method for the minimal invasive treatment of tumors. However, optimized nanomaterials to supply thermal stress inside the tumor remain to be identified. The present study investigates the therapeutic effects of magnetic hyperthermia induced by superparamagnetic iron oxide nanoparticles in two xenograft- models.

Material und Methodik:

Two different magnetic nanoparticles, synthesized via an aqueous (12 nm core size) and an organic route (15 nm core size) were analyzed in terms of their specific absorption rate (SAR), cell uptake and their effectively in hyperthermia treatment. Therefore mice were subcutaneously implanted with human breast adenocarcinoma (MDA-MB-231) and pancreatic cancer (BxPC-3) cells. After intratumoral injection of the magnetic nanoparticles, mice were exposed twice to an alternating magnetic field (AMF; H = 19 mT, f = 435 kHz, for 60 min) with an interval of seven days in between. The tumor surface temperature was monitored using an infrared thermography camera. 28 days after treatment, mice were sacrificed and tumor tissue was processed for histological analysis.

Ergebnisse:

A reduction of the tumor (MDA-MB-231: 17 – 27%; BxPC-3: 40 – 50% compared to untreated tumors) volume after MFH treatment could be observed over time in both cancer models, although the applied temperature dosages measured as CEM43T90 (cumulative equivalent minutes at 43 °C) were only between 1 and 24 min. Histological analysis of magnetic hyperthermia treated tumor tissue exhibited alterations in cell viability (apoptosis and necrosis) and showed a decreased cell proliferation.

Schlussfolgerungen:

The studied magnetic nanoparticles led to extensive cell death in human tumor xenografts and are considered suitable platforms for future multimodal hyperthermic applications.

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