# Development of Theranostic 177Lu-Labeled Polymeric Nanoparticles (177Lu-PNPs) for the Treatment of Head and Neck Cancer

## TL;DR

This study develops 177Lu-labeled nanoparticles for treating head and neck cancer, combining imaging and therapy to improve tumor targeting and reduce toxicity.

## Contribution

The novel theranostic platform integrates 177Lu radiolabeling with photothermal therapy for enhanced cancer treatment and monitoring.

## Key findings

- 177Lu-PNPs achieved high radiolabeling purity and preserved optical properties for NIR-II imaging.
- Combining PTT with 177Lu-PNPs significantly suppressed tumor growth and extended survival in mice.
- The therapy caused minimal toxicity, with stable body weight and normal organ histology observed.

## Abstract

This study presents the development of 177Lu-labeled
polymeric nanoparticles (PNPs) for theranostic applications in head
and neck cancer, utilizing both near-infrared II (NIR-II) and SPECT
imaging for targeted delivery and monitoring. The PNPs were surface-modified
with ethylenediamine and chelated with DTPA to enable 177Lu radiolabeling, achieving a radiochemical yield of 15.4% ±
3.2% and high purity (>95%). The radiolabeling process preserved
the
size distribution and optical properties of PNPs, facilitating their
use in NIR-II imaging, which confirmed effective tumor delivery with
peak uptake at 24 h postinjection. Photothermal therapy (PTT) combined
with 177Lu-PNPs significantly enhanced tumor uptake and
therapeutic efficacy, as shown by tumor growth suppression and extended
survival in treated mice. Importantly, mice receiving the 177Lu-PNPs-PTT combination therapy exhibited minimal toxicity, as indicated
by stable body weight and unaltered organ histology on H&E staining.
These findings demonstrate the potential of 177Lu-PNPs
as a safe and effective multifunctional platform for imaging-guided
photothermal-radionuclide cancer therapy.