Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Enabling Nanoparticles to Penetrate Deeply in Tumors

Abstract:
Too often, researchers designing nanoparticles capable of delivering effective doses of anticancer agents to tumors must balance the need to choose a nanoparticle that is small enough to escape the leaky blood vessels that surround tumors but large enough to avoid rapid clearance from the blood stream via the kidneys. Balancing these two requirements usually results in using nanoparticles that are indeed small enough to accumulate in the vicinity of tumors, but that are really too large to penetrate deeply enough into tumors to have the maximum therapeutic effect.

Enabling Nanoparticles to Penetrate Deeply in Tumors

Bethesda, MD | Posted on February 23rd, 2011

Now, a large team of researchers from the Massachusetts Institute of Technology, Massachusetts General Hospital, and Harvard Medical School have developed a solution to this problem: multilayered, or multistage, nanoparticles that partially dissolve once they accumulate around tumors, leaving behind a payload of nanoparticles a mere one-tenth the size of the original delivery vehicle. The remaining 10-nanometer-diameter nanoparticles, loaded with anticancer drugs, can then diffuse deeply into a tumor's dense interior.

Dai Fukumura, Moungi Bawendi, and Rakesh Jain, all senior faculty members at their respective institutions, directed this study. The team published their results in the Proceedings of the National Academy of Sciences. Dr. Bawendi is also a member of the MIT-Harvard Center for Cancer Nanotechnology Excellence funded by the National Cancer Institute.

The key to the new nanoparticles is a gelatin material that can serve as a substrate for enzymes that are produced at high levels by tumors. Cancer cells use these enzymes to dissolve the extracellular matrix that surrounds organs, enabling these malignant cells to escape into the bloodstream and colonize sites distant from the primary tumor. The researchers took advantage of this enzyme by embedding tiny nanoparticles within the gelatin core of the larger nanoparticles that they designed to be injected into the blood stream.

For this set of experiments, the investigators loaded 100-nanometer the gelatin nanoparticles with 10-nanometer quantum dots. While quantum dots are not likely to be used to deliver drugs to tumors, these nanobeacons produce bright optical signals that can be easily monitored as they are released from the larger nanoparticles. Initial experiments using tumors growing in culture showed that the gelatin-degrading enzymes did their job and that the released quantum dots were able to diffuse farther and more efficiently than the 100 nanometer particles into the tumors. Subsequent experiments in tumor-bearing mice confirmed these in vitro findings, and as a result, the investigators are now planning to repeat these experiments using drug loaded 10-nanometer particles in place of the quantum dots they used in this study.

Another approach to getting nanoparticles deep into tumors is to disrupt a tumor's ability to form the dense extracellular matrix, made of the protein collagen, that keeps nanoparticles in the outer regions of a tumor. Dr. Jain's group at MIT and the Harvard Medical School have done just that, using the widely used high-blood pressure medication Losartan to inhibit collagen synthesis. The investigators also published the results of these studies in the Proceedings of the National Academy of Sciences.

Human clinical studies have shown that Losartan reduces the incidence of cardiac and renal fibrosis by reducing the synthesis of one particular form of collagen, known as type I. Dr. Jain and his colleagues reasoned that this same inhibitory effect might lead to easier passage of nanoparticles into the deep recesses of a tumor. In fact, that is exactly the effect they observed at doses of the drug that were small enough to leave blood pressure unaffected. Tests showed that Doxil, the first approved nanoparticulate anticancer agent, was more effective at treating dense, fibrotic tumors, such as pancreatic tumors, growing in mice. Dr. Jain and his colleagues note in their paper that because long-term Losartan therapy has proven safe in humans, and because many anticancer agents raise blood pressure, administering Losartan with nanoparticles has the strong possibility of benefitting cancer patients.

####

About The National Cancer Institute (NCI)
The NCI Alliance for Nanotechnology in Cancer is engaged in efforts to harness the power of nanotechnology to radically change the way we diagnose, treat, and prevent cancer. Through its programs and initiatives, the Alliance is committed to building a community of researchers dedicated to using nanotechnology to advance the fight against cancer.

As part of the Center for Strategic Scientific Initiatives, the Alliance for Nanotechnology in Cancer works in concert with other NCI advanced technology initiatives to provide the scientific foundation and team science that is required to transform cancer research and care.

For more information, please click here

Contacts:
National Cancer Institute
Center for Strategic Scientific Initiatives
NCI Office of Cancer Nanotechnology Research (OCNR)
Building 31, Room 10A52
31 Center Drive, MSC 2580
Bethesda, MD 20892-2580
Telephone: (301) 451-8983

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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

View abstract - "Multistage nanoparticle delivery system for deep penetration into tumor tissue."

View abstract - "Losartan inhibits collagen I synthesis and improves the distribution and efficiency of nanotherapeutics in tumors."

Related News Press

News and information

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

Nanotubes/Buckyballs/Fullerenes

Easier, faster, cheaper: A full-filling approach to making nanotubes of consistent quality: Approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes July 19th, 2016

Sensing trouble: A new way to detect hidden damage in bridges, roads: University of Delaware engineers devise new method for monitoring structural health July 8th, 2016

Wireless, wearable toxic-gas detector: Inexpensive sensors could be worn by soldiers to detect hazardous chemical agents July 4th, 2016

Nanotubes' 'stuffing' as is: A scientist from the Lomonosov Moscow State University studied the types of carbon nanotubes' 'stuffing' June 2nd, 2016

Nanomedicine

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Pixel-array quantum cascade detector paves the way for portable thermal imaging devices: Research team from TU-Wien Center for Micro- and Nanostructures have developed a new 'cooler' sensing instrument thereby increasing energy-efficiency and enhancing mobility for diagnostic tes July 28th, 2016

Starpharma initiates new DEPô drug delivery program with AstraZeneca July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

Discoveries

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

Announcements

Scientists change properties of zeolites to improve hemodialysis July 29th, 2016

Novel state of matter: Observation of a quantum spin liquid July 29th, 2016

A new type of quantum bits July 29th, 2016

Lonely atoms, happily reunited July 29th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic