versatile nanoparticles offer great variety of diagnostic and therapeutic applications -
dynamic nanoparticles Kit Lam and colleagues from UC Davis and other institutions have created (NPS) which could provide an arsenal of applications to diagnose and treat cancer. Built on a polymer easy to do, these particles can be used as contrast agents to illuminate tumors for MRI and PET or deliver chemotherapy and other therapy to destroy tumors. In addition, the particles are biocompatible and showed no toxicity. The study was published online today.
"These are surprisingly useful particles," noted co-first author Yuanpei Li, a faculty member of the research in the laboratory of Lam. "As a contrast agent, they make easier tumors to see with MRI and other scans, we can also use them as vehicles to deliver chemotherapy directly to the tumor ;. Applying light to make the nanoparticles release oxygen singlet (photodynamic therapy) or use a laser to heat (photothermal therapy) -. all proven ways to destroy tumors "
Jessica Tucker, director of the drug program and Gene Delivery and devices at the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, said the approach described in the study has the ability to combine both imaging and therapy applications in a single platform, which was difficult to achieve, especially in an organic and therefore biocompatible vehicle.
"This is particularly useful in the treatment of cancer, where targeted treatment of tumor cells, and reduce the lethal effects in normal cells, is so critical," she added.
Although that not the first nanoparticles, they may be the most versatile. other particles are good for certain tasks, but not others. non-organic particles, such as quantum dots or gold based materials , work as well as diagnostic tools but have security problems. Organic probes are biocompatible and can deliver drugs, but imaging applications or phototherapy missing.
Built on an acid polymer porphyrin / cholic, nanoparticles are simple to perform and perform well in the body. Porphyrins are common organic compounds. cholic acid is produced by the liver. The basic nanoparticles 21 nanometers wide (a nanometer is a billionth of a meter).
To further stabilize the particles, the researchers added the amino acid cysteine (creation CNPs), which prevents the premature release of their therapeutic when exposed to blood proteins and other barriers. At 32 nanometers, CNPs are ideally sized to penetrate the tumors, accumulation between 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. Therapeutically, CNPs effectively transported anticancer drugs, such as doxorubicin. Even when stored in the bloodstream for several hours, CNPs only releases small amounts of drug; However, when exposed to light or agents such as glutathione, they easily freed from their payloads. The ability to precisely control the release chemotherapy within the tumor could greatly reduce toxicity. CNPs with doxorubicin provided excellent control of cancer in animals, with minimal side effects.
CNPs can also be configured to meet the light producing singlet oxygen, reactive molecules that destroy tumor cells. They may also generate heat when hit by the laser light. Significantly, CNPs may perform either the task when it is exposed to one of the light wavelength.
CNPs offer a number of benefits to improve imaging. They readily chelate imaging agents and can remain in the body for long periods. In animal studies, CNPs gathered in tumors, making them easier to read on an MRI. Because CNPs accumulated in tumors and not in normal tissues as they greatly improved the contrast of the tumor for MRI and can also be promising for PET-MRI.
This versatility offers multiple options for clinicians, as they mix and match applications.
"These particles can combine imaging and therapy," said Li. "We could possibly use them to simultaneously provide treatment and monitor treatment efficacy."
"These particles can also be used as optical sensors for image guided surgery," said Lam. "in addition, they can be used as powerful photosensitizers for intraoperative therapy."
while early results are promising, there is still a long way to go before CNPs can enter the clinic. Lam laboratory and colleagues will continue preclinical studies and, hopefully, go to trial humans. Meanwhile, the team welcomes these capabilities.
"this is the first nanoparticle perform many different jobs," said Li. "in providing chemotherapy, photodynamic and photothermal therapies to improve diagnostic imaging, it is the complete package. "
EmoticonEmoticon