A Combined Optical Nanotechnology Approach for Colon Cancer Screening

N. Iftimia, A.K. Iyer, S. Ganta, A. Singh, M. Amiji
Physical Sciences, Inc., US

Keywords: colon cancer, functionalized nanoparticles, optical imaging

Summary:

Colorectal cancer is one of the leading causes of cancer related deaths in North America alone. The standard clinical diagnosis of colorectal cancers relies almost exclusively on endoscopic examination of tissue followed by pathological determinations. However, the sensitivity of the traditional white-light endoscopy for cancer identification is rather poor, ranging from ~47% to 53%. Furthermore, if the cancer is detected at later stages when it has already spread to regional lymph nodes (stage III), the cure rate degrades significantly. We have recently investigated a new concept for early colon cancer screening using a combined nanotechnology-optical imaging approach. A cancer targeting contrast agent based on poly(epsilon-caprolactone) (PCL) microparticle (MPs) is used to enhance cancer-suspect regions, while a high resolution imaging is used to perform optical biopsy. For the preliminary investigation, the PCL based microparticles were functionalized with a cancer targeting RGD (arginine-glycine-aspartic-acid) peptide, which binds to ανβ3 integrin receptors (ABIR), overexpressed in several cancers, including cancers of epithelial origins. A pilot study using ApcMin mice demonstrated preferential staining/homing of the targeted MPs to abnormal/diseased tissue, as indicated by both microscopy and laser-induced fluorescence imaging, and optical imaging capability to differentiate between normal mucosal areas, early dysplasia, and adenocarcinoma.