Gold Nanorods Based Air Scanning Electron Microscopy and Diffusion Reflection Imaging for Mapping Tumor Margins in Squamous Cell Carcinoma

Abstract

A critical challenge arising during a surgical procedure for tumor removal is the determination of tumor margins. Gold nanorods (GNRs) conjugated to epidermal growth factor receptors (EGFR) (GNRs-EGFR) have long been used in the detection of cancerous cells as the expression of EGFR dramatically increases once the tissue becomes cancerous. Optical techniques for the identification of these GNRs-EGFR in tumor are intensively developed based on the unique scattering and absorption properties of the GNRs. In this study, we investigate the distribution of the GNRs in tissue sections presenting squamous cell carcinoma (SCC) to evaluate the SCC margins. Air scanning electron microscopy (airSEM), a novel, high resolution microscopy is used, enabling to localize and actually visualize nanoparticles on the tissue. The airSEM pictures presented a gradient of GNRs from the tumor to normal epithelium, spread in an area of 1 mm, suggesting tumor margins of 1 mm. Diffusion reflection (DR) measurements, performed in a resolution of 1 mm, of human oral SCC have shown a clear difference between the DR profiles of the healthy epithelium and the tumor itself.

Hyperlipidemic mice as a model for a real‐time in vivo detection of atherosclerosis by gold nanorods‐based diffusion reflection technique

“…This GNRs-based DR technique has been under study for the last 6 years [22][23][24][25][26][27]. With this technique, our group has achieved successful detection of head and neck cancer, margin of oral cancer and AS in a carotid-artery-injured rat model.…”

Future trends and emerging issues for nanodelivery systems in oral and oropharyngeal cancer

“…This is a useful instrument for mapping tumor margins by quantification of anti-EGFR-GNRs. 65 The physical properties of GNRs, like their reflectance, allow discrimination of normal tissue from tumors. 64 Another important feature of GNRs is the unique scattering and absorption capacity evaluated using SEM.…”

“…64 Another important feature of GNRs is the unique scattering and absorption capacity evaluated using SEM. 65 The technique needs to be standardized prior to its clinical application.…”

Identification of Postoperative Margins of Glioblastoma Multiforme Using Gold Nanoparticles Conjugated to Epidermal Growth Factor Antibodies

“…On scanning of the GNP-stained slides with a high-resolution scanning electron microscope (airSEM™) [21], the anti-EGFRconjugated GNPs could be visualized in the tissue (Figure 3). As shown in Figure 3, a higher concentration was detected in cells in the tumor area than in the infiltrating cells in the adjacent area.…”