Surface modified NIR magnetic nanoprobes for theranostic applications.

Objectives: Near-Infrared based imaging modalities integrated with thermotherapy can facilitate detection of cancer at early stages and mediate high-resolution image-guided hyperthermia. In this work, fluorescent iron oxide nanoparticles (FIO) have been developed possessing deep tissue penetrable NIR imaging and site-specific magnetic hyperthermia characteristics for the elimination of cancer cells. Methods: One-pot synthesis of amine-functionalized superparamagnetic iron oxide nanoparticles (HIO) were achieved using ethylenediamine (EDA) facilitated conjugation of indocyanine green (ICG) mediated by electrostatic interactions. Results: EDA acts as a capping and reducing agent to direct the structural growth of hydrophilic Fe3O4 nanocrystals with high saturation magnetization, specific absorption rate, and T-2 value of 118 emu/g, 329.8 +/- 5.96 W/g, and 40.17 mM(-1)s(-1), respectively. Here, Fe2+/Fe3+ of two was maintained to achieve magnetite nanocrystals contradictory to the gold standard ratio of 0.5 without additives for nucleation and growth. Developed FIO showed excellent cytocompatibility even at higher concentrations and on subjecting to magnetic hyperthermia reduced its survival percentage. FIO biodistribution in mice showed enhanced half-life than free ICG with preferential localization in the brain and liver. Conclusion: Developed FIO using a facile technique is a potential clinical alternative for cellular tracking, imaging, and hyperthermia.

Automated summary

The study developed fluorescent iron oxide nanoparticles with deep tissue penetrable NIR imaging and site-specific magnetic hyperthermia characteristics. The nanoparticles showed excellent cytocompatibility even at high concentrations and reduced cell survival rates after magnetic hyperthermia treatment. Additionally, they exhibited enhanced biodistribution in mice with preferential localization in the brain and liver.