Radioactive (Y) upconversion nanoparticles conjugated with recombinant targeted toxin for synergistic nanotheranostics of cancer.

We report combined therapy using upconversion nanoparticles (UCNP) coupled to two therapeutic agents: beta-emitting radionuclide yttrium-90 (Y) fractionally substituting yttrium in UCNP, and a fragment of the exotoxin A derived from genetically fused with a targeting designed ankyrin repeat protein (DARPin) specific to HER2 receptors. The resultant hybrid complex UCNP-R-T was tested using human breast adenocarcinoma cells SK-BR-3 overexpressing HER2 receptors and immunodeficient mice, bearing HER2-positive xenograft tumors. The photophysical properties of UCNPs enabled background-free imaging of the UCNP-R-T distribution in cells and animals.

The double heterostructure: the concept and its applications in physics, electronics, and technology (Nobel lecture).

The art and science of heterostructure design has not remained still since its founding: While the theoretical principles initially advanced rapidly, experimental realization initially lagged until the ideal AlGaAs solid solutions were found. From this point, development into application proceeded apace. In this Review, these intial steps and the current position of heterostructure applications are surveyed.