Phthalocyanine-Blue Nanoparticles for the Direct Visualization of Tumors with White Light Illumination

The current standard of care for colon cancer surveillancereliesheavily on white light endoscopy (WLE). However, dysplastic lesionsthat are not visible to the naked eye are often missed when conventionalWLE equipment is used. Although dye-based chromoendoscopy shows promise,current dyes cannot delineate tumor tissues from surrounding healthytissues accurately. The goal of the present study was to screen variousphthalocyanine (PC) dye-loaded micelles for their ability to improvethe direct visualization of tumor tissues under white light followingintravenous administration. Zinc PC (tetra-tert-butyl)-loadedmicelles were identified as the optimal formulation. Their accumulationwithin syngeneic breast tumors led the tumors to turn dark blue incolor, making them clearly visible to the naked eye. These micelleswere similarly able to turn spontaneous colorectal adenomas in Apc(+/Min) mice a dark blue color for easy identification and couldenable clinicians to more effectively detect and remove colonic polyps.

Automated summary

The current standard of care for colon cancer surveillance, white light endoscopy, often misses dysplastic lesions that are not visible to the naked eye. Dye-based chromoendoscopy shows promise but lacks accuracy in differentiating tumor tissues from healthy tissues. This study aimed to improve tumor tissue visualization using various phthalocyanine (PC) dye-loaded micelles administered intravenously. Zinc PC (tetra-tert-butyl)-loaded micelles were identified as the optimal formulation, turning tumors dark blue for easy identification. These micelles were also effective in turning colorectal adenomas in mice a dark blue color, aiding in their detection and removal.