# Nanoparticle Uptake in the Aging and Oncogenic Drosophila Midgut Measured with Surface-Enhanced Raman Spectroscopy

## TL;DR

This study uses nanoparticles and Raman spectroscopy to detect early signs of gut tumors in fruit flies, showing potential for non-invasive cancer diagnostics.

## Contribution

The study introduces a novel method using SERS NPs to detect early tumor formation in Drosophila midguts before visible damage occurs.

## Key findings

- Tumorigenic flies showed significant nanoparticle retention in the gut 2 days after oncogene induction, before epithelial damage.
- Nanoparticle signals were localized to the posterior midgut region with high stem cell activity.
- No significant nanoparticle retention was observed in healthy young or old flies after gut clearance.

## Abstract

Colorectal cancer remains a major global health concern. Colonoscopy, the gold-standard colorectal cancer diagnostic, relies on the visual detection of lesions and necessitates invasive biopsies for confirmation. Alternative diagnostic methods, based on nanomedicine, can facilitate early detection of malignancies. Here, we examine the uptake of surface-enhanced Raman scattering nanoparticles (SERS NPs) as a marker for intestinal tumor detection and imaging using an established Drosophila melanogaster model for gut disease. Young and old Oregon-R and w1118 flies were orally administered SERS NPs and scanned without and upon gut lumen clearance to assess nanoparticle retention as a function of aging. Neither young nor old flies showed significant NP retention in their body after gut lumen clearance. Moreover, tumorigenic flies of the esg-Gal4/UAS-RasV12 genotype were tested for SERS NP retention 2, 4 and 6 days after RasV12 oncogene induction in their midgut progenitor cells. Tumorigenic flies showed a statistically significant NP retention signal at 2 days, well before midgut epithelium impairment. The signal was then visualized in scans of dissected guts revealing areas of NP uptake in the posterior midgut region of high stem cell activity.