We report the first targeted nuclear medicine application of the lanthanum radionuclides 132/135La. These isotopes represent a matched pair for diagnosis via the positron emissions of 132La and therapy mediated by the Auger electron emissions of 135La. We identify two effective chelators, known as DO3Apic and macropa, for these radionuclides. The 18‐membered macrocycle, macropa, bound 132/135La with better molar activity than DO3Apic under similar conditions. These chelators were conjugated to the prostate‐specific membrane antigen (PSMA)‐targeting agent DUPA to assess the use of radiolanthanum for in vivo imaging. The 132/135La‐labeled targeted constructs showed high uptake in tumor xenografts expressing PSMA. This study validates the use of these radioactive lanthanum isotopes for imaging applications and motivates future work to assess the therapeutic effects of the Auger electron emissions of 135La.
We demonstrate super-resolution chemical
imaging with plasmonic
nanoholes via surface-enhanced Raman spectroscopy (SERS). Due to large
field enhancements, blinking behavior of SERS hot spots was observed
and processed using a stochastic optical reconstruction microscopy
(STORM) algorithm. This enabled localization to within 10 nm and high-resolution
imaging. However, illumination of the sample with a static laser beam
produced only SERS hot spots in fixed locations, leaving noticeable
gaps in the final images. By randomly altering the phase profile of
the incident beam with a simple optical diffuser, the hot spots were
shifted across the plasmonic surface to illuminate different areas
of the sample, thereby rendering a final image without the gaps. A
tunable band-pass filter was used to preserve spectral information,
allowing chemical contrast imaging. Images were then compared to those
obtained with a scanning electron microscope. Finally, we show that
super-resolution SERS images can also be obtained with our dynamic
illumination technique on even the most basic plasmonic substrate:
as-deposited rough silver films. These results show significant potential
for the use of simple plasmonic substrates with straightforward illumination
and collection schemes for super-resolution chemical imaging.
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