Probe Tailored for Tumors

According to the investigators at Memorial Sloan-Kettering Cancer Center (MSKCC) and Cornell University, the particles are biologically safe, stable, and small enough to be easily transported across the body's structures and efficiently excreted through the urine. All of these properties have been successfully engineered on a single-particle platform, called "C dots," in order to optimize the biological behavior and imaging properties of nanoparticles for use in a wide array of biomedical and life science applications.

Imaging experiments in mice conducted at MSKCC showed that this new particle platform, or "probe," can be molecularly customized to target surface receptors or other molecules that are expressed on tumor surfaces or even within tumors, and then imaged to evaluate various biological properties of the tumor, including the extent of a tumor's blood vessels, cell death, treatment response, and invasive or metastatic spread to lymph nodes and distant organs.

Many of the contrast agents or probes currently used in medical imaging (such as GdDTPA for magnetic resonance imaging) are not specific to any particular tumor type. According to the MSKCC researchers, the information gained from imaging tumors targeted with C dots may ultimately assist physicians in defining tumor borders for surgery, determining the extent of a tumor's spread, mapping lymph node disease, and improving real-time visualization of small vascular beds, anatomic channels, and neural structures during surgery.

Created at Cornell University and modified at MSKCC, C dots have been optimized for use in optical and PET imaging and can be tailored to any particle size without adversely impacting its fluorescent properties.

Their inner "core" is encapsulated in a shell of silica, a nontoxic element naturally found in fruits, grains, and vegetables, and contains optical dyes that emit light at longer wavelengths, resulting in an overall improvement in image quality compared to dyes that are commercially available.

The scientists explain that while the next generation of nanoparticles holds much clinical promise, more work needs to be done before C dots are approved for use in humans.; Source: Memorial Sloan-Kettering Cancer Center