Nanoparticle-Enhanced molecular Fluorescence-Endoscopy for detection of early-stage colorectal adenocarcinomas

Colorectal cancer has low survival rate. More than half of the patients diagnosed with the disease die during the first five years. Colorectal cancer is today diagnosed by colonoscopy, a method where a fiber-optic tube is introduced into the intestine to take pictures of the intestine wall. A large portion of small tumor lesions are not detected by this method. The main goal of the project is to develop a method for early-stage diagnosis of colorectal cancer based on fluorescence optical imaging endoscopy, suitable for routine screening. Early detection will contribute to higher survival rate for these patients. At an early stage the cancer is small and difficult to detect. In this project the goal is to improve the detection method by specifically label the cancer cells with highly fluorescent dyes. This will be performed by encapsulating fluorescent dyes into nanoparticles and then proteins (targeting ligands) which specifically bind to cancer cells will be coupled to the surface of the nanoparticles. The main objective for SINTEF is the development and optimization of biodegradable nanoparticles containing fluorescent tracers and targeting ligands. High fluorescent brightness and high specificity for cancer cell targeting are important properties of these nanoparticles. The nanoparticles will then be tested by the German partner in endoscopy studies in mice. NanoEFEct is a transnational European project with partners from Austria, Germany, Norway and Portugal. SINTEF has developed and optimized highly fluorescent, biodegradable nanoparticles, which have been tested by the German partner and which are clearly visible in equipment for endoscopy used on a daily basis by clinicians. Several different fluorescent dyes have been encapsulated in various amounts and brightness and visibility has been tested. Three candidates have been selected as especially promising and optimal amounts of dye with respect to signalling are found. Thereby, the goal of high fluorescent brightness has been achieved. Various types of targeting ligands for cancer cells were then immobilized onto the surface of these particles. These particles were tested in in vitro cell-based assays for biological efficacy by the German partner. A higher labeling of mouse colorectal cancer cells was observed for nanoparticles with specific targeting ligands compared to nanoparticles with random targeting ligands or nanoparticles without targeting ligands as control. These promising results are a first proof-of-concept, but since the nanoparticles showed relatively high non-specific binding to both cancer cells and healty intestine cells, the signal/noise ratio is still too low for a highly sensitive diagnostic analysis. Therefore, further optimalisation and development of the nanoparticles will be needed, as well as the discovery of still more specific targeting ligands. All in all, this project has to a great extent contributed towards a novel contrast agent for highly sensitive early diagnosis of colorectal cancer.

NanoEFEct is a transnational European project with partners from Austria (coordinator), Germany, Norway and Portugal. The main goal of the project is to develop an early-stage diagnosis of colorectal cancer based on molecular-targeted fluorescence optical imaging endoscopy, suitable for routine screening. Control of colorectal carcinoma (CRC) is hindered because early cancerous lesions in the colorectal wall may not be visible at colonoscopy, a screening technique allowing diagnosis and immediate resectio n of CRC. Colonoscopy misses 6% of all CRCs and 12-17% of adenomas larger than 1cm. To improve detection of early-stage CRC, we propose nanoparticle-enhanced fluorescence endoscopy. Targeting groups attached to the nanoparticles will bind them securely an d specifically to EpCAM proteins heavily upregulated on ca. 98 % of CRC cell surfaces, analogously to the binding underlying the licensed antibody therapy using Catumaxomab. Fluorescent tags on the nanoparticles will allow contrasty imaging in a fluoresce nce endoscope. Closely cooperating with surgeons and pathologists, diagnostically relevant nanoparticles will be prepared by GMP, ready for rapid translational development towards preclinical testing at the end of the project. Ethical and regulatory issue s are addressed from the beginning to guide the research direction from the start. The consortium of 5 partners includes teams developing biodegradable nanoparticles for molecular imaging, a team working clinically and scientifically with fluorescence end oscopy in patients and in mouse models, and a team of scientists and clinicians widely experienced in the complex regulatory, legal and ethical issues associated with nanomedicine and with translational work bringing pharmaceutical products into clinical use.