Built on a porphyrin/cholic acid polymer, the nanoparticles are simple to make and perform well in the body. Porphyrins are common organic compounds. Cholic acid is produced by the liver. The basic nanoparticles are 21 nanometers wide (a nanometer is one-billionth of a meter).
To further stabilize the particles, the researchers added the amino acid cysteine (creating CNPs), which prevents them from prematurely releasing their therapeutic payload when exposed to blood proteins and other barriers. At 32 nanometers, CNPs are ideally sized to penetrate tumors, accumulating among cancer cells while sparing healthy tissue.
In the study, the team tested the nanoparticles, both in vitro and in vivo, for a wide range of tasks. On the therapeutic side, CNPs effectively transported anti-cancer drugs, such as doxorubicin. Even when kept in blood for many hours, CNPs only released small amounts of the drug; however, when exposed to light or agents such as glutathione, they readily released their payloads. The ability to precisely control chemotherapy release inside tumors could greatly reduce toxicity. CNPs carrying doxorubicin provided excellent cancer control in animals, with minimal side effects.
CNPs also can be configured to respond to light, producing singlet oxygen, reactive molecules that destroy tumor cells. They can also generate heat when hit with laser light. Significantly, CNPs can perform either task when exposed to a single wavelength of light.
CNPs offer a number of advantages to enhance imaging. They readily chelate imaging agents and can remain in the body for long periods. In animal studies, CNPs congregated in tumors, making them easier to read on an MRI. Because CNPs accumulated in tumors, and not so much in normal tissue, they dramatically enhanced tumor contrast for MRI and may also be promising for PET-MRI scans.
This versatility provi
|Contact: Dorsey Griffith|
University of California - Davis Health System