| Imagine being able to find metastatic dormant cancer | | | | able to be detected up to 10 to 12 cms through |
| cells far too small to be detected by MRI, CT or | | | | breast tissue and 5 to 6 cm through muscle tissue. |
| PET scans. Research being conducted at the | | | | Because the polymersomes are made of nontoxic |
| University of Pennsylvania has successfully | | | | materials they differ from other contrast |
| demonstrated this ability using animal models. | | | | agents currently used in imaging for CT and MRI. |
| The experiment, involves synthetic, biocompatible | | | | The application of this technique is quite far |
| flourescent materials called porphyrins which are | | | | reaching. Think of these polymere chains as a train |
| embedded into the water-resistant cell membranes | | | | that is able to carry the porphyrins (to light up and |
| of a string of molecules. These strings, called | | | | identify the cancer cells) and carry the |
| polymeres, are mechanically strong yet flexible | | | | chemotherapy agents to destroy the cancer cells. |
| enough to squeeze through the microcirculation | | | | Because cancer cells have specific chemical markers |
| without being damaged. | | | | on their outer membrane, specific chemical |
| Recently, Peter Ghoroghchian from the Department | | | | substances can be developed that will attach to |
| of Bioengineering, embedded these flourescent | | | | the cancer cell's outer membrane. Current |
| porphyrins in a tumor located one centimeter beneath | | | | chemotherapy is non-selective meaning that it targets |
| the skin of a mouse. He then shone near-infrared | | | | all cells that are rapidly growing, killing good and bad |
| light onto the skin which triggered the flourescent | | | | cells alike. This new technology will enable doctors |
| materials, illuminating the tumour. Using | | | | to find cancer cells that are too small to be |
| near-infrared wavelengths enables these signals to | | | | detected and deliver chemotherapy to the site |
| pass through water, blood cells and other compounds | | | | leaving healthy tissues intact. |
| that make up tissue. In other words, the signals are | | | | |