During prolonged exposure to high temperatures, the heat-regulating mechanisms of the body eventually become overwhelmed and unable to effectively deal with the heat, causing the body temperature to rise uncontrollably causing the condition called hyperthermia. Hyperthermia can be induced artificially with drugs or medical devices.
Hyperthermia therapy may be used to treat cancer and other conditions. Heating up to over 40–45°C can lead to a destruction of tumor tissue making hyperthermia therapy a promising therapeutic approach for cancer therapy in combination with chemotherapy or radiotherapy. However, confinement of the heating effect in hyperthermia cancer therapy within the tumor tissue is a challenge.
Superparamagnetic iron oxide nanocrystals modified with targeting molecules can be confined to tumor sites. Once confined, these can serve as heat generator in the presence of an electrically induced (AC) magnetic field that converts the magnetic energy to thermal energy causing hyperthermia. Ocean NanoTech is currently solving the challenges of using our superparamagnetic iron oxide nanocrystals for hyperthermia such as: 1) optimization of the amount of nanocrystals at the tumor site to cause an effective rise of the local temperature; 2) reduction of the RES uptake; and 3) specially designed superparamagnetic iron oxide nanocrystals with high specific heat for a fast absorption rate (SAR). The high (Ms) of magnetic nanocrystals is essential to achieve high SAR.
In order to demonstrate the feasibility of using Ocean’s IO nanocrystals for hyperthermia, we examined their efficacy to generate heat when exposed to a high-frequency magnetic field. Our preliminary studies showed size dependent magnetization saturation using 5 nm and 10 nm diameter iron oxide nanocrystals (Catalog # SHP).
The iron oxide nanocrystals can produce heat in an alternating magnetic field, indicating that these nanocrystals can be used as novel hyperthermic agents that can potentially be used to destroy tumor tissues. Further studies are on-going at Ocean NanoTech to eliminate the challenges of using our superparamagnetic iron oxide nanocrystals for hyperthermia therapy.