Imagine being able to find metastatic dormant cancer cells far too small to be detected by MRI, CT or PET scans. Research being conducted at the University of Pennsylvania has successfully demonstrated this ability using animal models. The experiment, involves synthetic, biocompatible flourescent materials called porphyrins which are embedded  into the water-resistant cell membranes of a string of molecules. These strings, called polymeres, are mechanically strong yet flexible enough to squeeze through the microcirculation without being damaged.

Recently,  Peter Ghoroghchian from the Department of Bioengineering, embedded these flourescent porphyrins in a tumor located one centimeter beneath the skin of  a mouse. He then shone near-infrared light onto the skin which  triggered the flourescent materials, illuminating the tumour. Using near-infrared wavelengths enables these signals to pass through water, blood cells and other compounds that make up tissue. In other words, the signals are able to be detected up to 10 to 12 cms through breast tissue and 5 to 6 cm through muscle tissue. Because the polymersomes are made of nontoxic materials they differ from other contrast agents  currently used in imaging for CT and MRI.

The application of this technique is quite far reaching. Think of these polymere chains as a train that is able to carry the porphyrins (to light up and identify the cancer cells) and carry the chemotherapy agents to destroy the cancer cells. Because cancer cells have specific chemical markers on their outer membrane, specific chemical substances can be developed that will attach  to the cancer cell’s  outer membrane. Current chemotherapy is non-selective meaning that it targets all cells that are rapidly growing, killing good and bad cells alike.  This new technology will enable doctors to find cancer cells that are too small to be detected  and deliver chemotherapy to the site leaving healthy tissues intact.

For more information about this fascinating research, follow this link to the National Institute of Biomedical Imaging and Bioengineering.

As a family nurse practitioner and quality assurance manager of a busy 5 practice physician group, Margaret Mastrangelo has over 15 years of healthcare experience. In addition, she taught high school English for over a decade in Australia. Margaret has always been fascinated by the human body, why disease and illness occur and the mind-body connection. She is a certified scuba diver and a licensed private pilot and given any opportunity, you’ll find her out flying. In her spare time, she is currently developing a web site providing health information for consumers.