Advancing radiology through informed leadership: summary of the proceedings of the Seventh Biannual Symposium of the International Society for Strategic Studies in Radiology (IS(3)R), 23-25 August 2007

Enhancement of cell permeabilization apoptosis-inducing activity of selenium nanoparticles by ATP surface decoration

A simple method for preparation of adenosine triphosphate (ATP) surface-functionalized selenium nanoparticles (SeNPs@ATP) with enhanced cell permeabilization and anticancer activity has been demonstrated in the study reported in this article. Spherical SeNPs were decorated with ATP by strong adsorption through an Se-N bond, leading to the highly stable structure of the conjugates. ATP surface decoration significantly enhanced the cellular uptake and anticancer activity of SeNPs. Induction of apoptosis in HepG2 human hepatocellular carcinoma cells by SeNPs@ATP was evidenced by accumulation of the sub-G1 cell population, phosphatidylserine exposure, DNA fragmentation, PARP cleavage and caspase activation. Further studies found that SeNPs@ATP treatment triggered the depletion of mitochondrial membrane potential and reactive oxygen species (ROS) overproduction. Our results demonstrate that the use of ATP as a surface decorator of SeNPs is a novel strategy to achieve anticancer synergy. SeNPs@ATP may be a candidate for further evaluation as a chemotherapeutic agent for human cancers.

FROM THE CLINICAL EDITOR

In this paper, adenosine triphosphate (ATP) surface-functionalized selenium nanoparticles are discussed as cell-penetrating anticancer agents. Conjugates are stable and ATP functionalization greatly enhances the apoptosis induction properties of the selenium nanoparticles in HepG2 human hepatocellular carcinoma cells.

Magnetic navigation in ultrasound-guided interventional radiology procedures

AIM

To evaluate the usefulness of magnetic navigation in ultrasound (US)-guided interventional procedures.

MATERIALS AND METHODS

Thirty-seven patients who were scheduled for US-guided interventional procedures (20 liver cancer ablation procedures and 17 other procedures) were included. Magnetic navigation with three-dimensional (3D) computed tomography (CT), magnetic resonance imaging (MRI), 3D US, and position-marking magnetic navigation were used for guidance. The influence on clinical outcome was also evaluated.

RESULTS

Magnetic navigation facilitated applicator placement in 15 of 20 ablation procedures for liver cancer in which multiple ablations were performed; enhanced guidance in two small liver cancers invisible on conventional US but visible at CT or MRI; and depicted the residual viable tumour after transcatheter arterial chemoembolization for liver cancer in one procedure. In four of 17 other interventional procedures, position-marking magnetic navigation increased the visualization of the needle tip. Magnetic navigation was beneficial in 11 (55%) of 20 ablation procedures; increased confidence but did not change management in five (25%); added some information but did not change management in two (10%); and made no change in two (10%). In the other 17 interventional procedures, the corresponding numbers were 1 (5.9%), 2 (11.7%), 7 (41.2%), and 7 (41.2%), respectively (p=0.002).

CONCLUSION

Magnetic navigation in US-guided interventional procedure provides solutions in some difficult cases in which conventional US guidance is not suitable. It is especially useful in complicated interventional procedures such as ablation for liver cancer.