Superparamagnetic nanoparticle clusters for cancer theranostics combining magnetic resonance imaging and hyperthermia treatment.

摘要: Superparamagnetic nanoparticles (SPIONs) could enable cancer theranostics if magnetic resonance imaging (MRI) and hyperthermia treatment (MHT) were combined. However, the particle size of SPIONs is smaller than pores fenestrated capillaries in normal tissues because superparamagnetism expressed only at a <10 nm. Therefore, leak from tissues, resulting low accumulation tumors. Furthermore, MHT studies have been conducted an impractical way: direct injection materials into tumor application hazardous alternating current (AC) fields. To accomplish effective enhancement MRI contrast agents tumors inhibition growth by with intravenous safe AC field, we clustered not to prevent their leakage but also for increasing relaxivity specific absorption rate. We modified clusters folic acid (FA) polyethylene glycol (PEG) promote SPION clustering cluster modification FA PEG achieved simultaneously via thiol-ene click reaction. Twenty-four hours after FA- PEG-modified nanoclusters (FA-PEG-SPION NCs), they accumulated locally (not necrotic) within enhanced contrast. 24 h NCs, mice placed field H = 8 kA/m f 230 kHz (Hf 1.8×10(9) A/m∙s) 20 min. The underwent local heating field. temperature was higher surrounding ≈6°C min treatment. Thirty-five days treatment, volume treated one-tenth that control mice. alive 12 weeks; died up weeks