- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
Quantum dots, small semiconductor nanoparticles that fluoresce brightly with sharply defined colors, have tremendous promise as biomedical imaging agents except for one problem—most are made from potentially hazardous materials such as cadmium and selenium. Now, however, a collaborative effort between researchers at Stanford University and Xiamen University in China has produced a stable, biocompatible quantum dot that appears to have the desired set of properties needed for biomedical imaging.
The team led by Zhen Cheng of Xiamen University and Sanjiv Gambhir of Stanford University School of Medicine reported its work in the journal Nano Letters. Dr. Gambhir is the co-principal investigator of the Stanford University Center for Cancer Nanotechnology Excellence and Translation.
To solve the biocompatibility problem, the investigators searched for semiconducting materials that had the desired optical properties of fluorescing in the near-infrared region of the spectrum and yet were not potentially toxic. They settled on a combination of indium phosphide and zinc sulfide and created a nanoparticle with an indium phosphide core and a zinc sulfide shell. The resulting quantum dots fluoresced brightly at 710 nanometers, a wavelength of light that passes through biological tissues and can be seen from within the body. To improve the pharmacological properties of the quantum dots—their ability to travel unimpeded through the blood stream, penetrate tissues, and reach biological targets—the researchers coated the nanoparticles with a biocompatible polymer known as a dendrimer. This coating also served as a convenient attachment point for a three amino acid peptide arginine-glycine-aspartic acid, known as RGD, that targets many types of tumors.
Tests with cancer cells and tumor-bearing animals demonstrated that these nanoprobes clearly imaged tumors known to bind to RGD. Because of their small size, the quantum dots accumulated in tumors via the leaky blood vessels that surround tumors. Biodistribution tests showed that approximately 60 percent of an injected dose of the new quantum dots was cleared from the body within a day, and that 100 percent clearance was achieved within one week. Equally important, animals dosed with this new type of nanoparticle experienced no apparent ill effects.
About The National Cancer Institute (NCI)
To help meet the goal of reducing the burden of cancer, the National Cancer Institute (NCI), part of the National Institutes of Health, is engaged in efforts to harness the power of nanotechnology to radically change the way we diagnose, treat and prevent cancer.
The NCI Alliance for Nanotechnology in Cancer is a comprehensive, systematized initiative encompassing the public and private sectors, designed to accelerate the application of the best capabilities of nanotechnology to cancer.
Currently, scientists are limited in their ability to turn promising molecular discoveries into benefits for cancer patients. Nanotechnology can provide the technical power and tools that will enable those developing new diagnostics, therapeutics, and preventives to keep pace with today’s explosion in knowledge.
For more information, please click here
National Cancer Institute
Office of Technology & Industrial Relations
ATTN: NCI Alliance for Nanotechnology in Cancer
Building 31, Room 10A49
31 Center Drive , MSC 2580
Bethesda , MD 20892-2580
Copyright © The National Cancer Institute (NCI)If you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
|Related News Press|
News and information
A compact, efficient single photon source that operates at ambient temperatures on a chip: Highly directional single photon source concept is expected to lead to a significant progress in producing compact, cheap, and efficient sources of quantum information bits for future appls May 3rd, 2016
Superfast light source made from artificial atom April 28th, 2016
Quantum dots enhance light-to-current conversion in layered semiconductors: Research demonstrates promise of a new approach for improving solar cells, photocatalysts, light sensors, and other optoelectronic devices April 11th, 2016
Revealing the ion transport at nanoscale March 30th, 2016
Sweet 'quantum dots' light the way for new HIV and Ebola treatment March 15th, 2016