Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Magnetic Nanoworms and Nanocrystals Deliver siRNA to Tumors

Abstract:
Small pieces of nucleic acid known as short interfering RNAs, or siRNAs, can turn off the production of specific proteins, a property that makes them one of the more promising new classes of anticancer drugs in development. Indeed, at least two siRNA-based anticancer therapies, both delivered to tumors in nanoparticles, have begun human clinical trials.

Magnetic Nanoworms and Nanocrystals Deliver siRNA to Tumors

Bethesda , MD | Posted on September 23rd, 2009

Now, investigators at the Massachusetts Institute of Technology (MIT) have developed a modular nanoparticle-based drug delivery system that maximizes the quantity of siRNA molecules that not only can enter cells but also can escape into the cytoplasm, where they can interfere with protein production. Sangeeta Bhatia, M.D., Ph.D., and Phillip A. Sharp, Ph.D., of the MIT-Harvard Center of Cancer Nanotechnology Excellence, and Alain Charest, Ph.D., M.Sc., Tufts University School of Medicine, led the study, whose results appear in the journal ACS Nano.

The new siRNA delivery vehicle is made of dendrimer-conjugated magnetic and fluorescent nanoworms that the investigators call "dendriworms." Dendrimers are synthetic polymers that generally have a spherical shape and that can be readily modified to carry a wide range of molecules, including nucleic acids. In this work, Dr. Bhatia and her colleagues used polyamidoamine dendrimers, which a large body of preclinical work has shown are fully biocompatible, and coupled them to a chain of magnetic nanoparticles known as a nanoworm. The investigators also added a fluorescent molecule to the nanoworms, thereby creating a drug delivery vehicle that they could also image in the body using either magnetic resonance imaging or fluorescence imaging. In a final step, the researchers added siRNA to the dendriworms. The resulting construct, which contains approximately 7 magnetic nanoparticles, 45-50 dendrimers, and 50 siRNA molecules, was stable under test conditions for up to 6 hours.

When added to cells growing in culture, this siRNA-dendrimer complex rapidly entered the cells and then escaped into the cellular cytoplasm. The researchers observed no significant toxicity in these in vitro experiments. When the dendriworms were administered to human glioblastoma cells, the delivered siRNA was able to silence production of the targeted gene, in this case a mutant gene known to be involved in glioblastoma development.

To test whether this dendriworm would work in a living animal, the researchers used a strain of mice that were genetically engineered to develop glioblastoma tumors spontaneously in the brain. The investigators found that the dendriworms were able to penetrate the tumors, deliver their therapeutic siRNA cargo into tumor cells, and silence the targeted gene in those cells.

Meanwhile, a group of investigators at The Jikei University School of Medicine in Tokyo, Japan, led by Yoshihisa Namiki, M.D., has demonstrated that lipid-coated magnetic crystals can safely and effectively deliver therapeutic siRNA to tumors in mice. The results of their experiments were published in the journal Nature Nanotechnology.

Dr. Namiki and his colleagues created their delivery vehicle by coating iron oxide nanocrystals with a layer of positively charged lipids. This layer binds strongly to siRNA molecules, which— like all nucleic acids—have a strong negative charge. After optimizing the lipid coating to maximize siRNA delivery efficiency, the investigators used their nanoparticle to deliver an anti-EGFR siRNA to gastric tumors in mice. After injecting the mice with the therapeutic nanoparticles, the investigators applied a local magnetic field around the vicinity of the tumor. After 28 days, tumors in the treated mice were 50% smaller compared with tumors in mice treated with just the nanoparticle and no siRNA.

####

About National Cancer Institute
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

Contacts:
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 © National Cancer Institute

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 - “Functional delivery of siRNA in mice using dendriworms.”

View abstract - “A novel magnetic crystal-lipid nanostructure for magnetically guided in vivo gene delivery.”

Related News Press

News and information

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Oxford Instruments’ TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

X-rays and electrons join forces to map catalytic reactions in real-time: New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions June 29th, 2015

Graphene breakthrough as Bosch creates magnetic sensor 100 times more sensitive than silicon equivalent June 28th, 2015

Building a better semiconductor: Research led by Michigan State University could someday lead to the development of new and improved semiconductors June 27th, 2015

Nanomedicine

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Efforts to Use Smart Nanocarriers to Cure Leukemia Yield Promising Results June 29th, 2015

Chivalrous Knight Does Pro Bono June 27th, 2015

Discoveries

Chitosan coated, chemotherapy packed nanoparticles may target cancer stem cells June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Visible Light-Sensitive Photocatalysts Used for Purification of Contaminated Water in Iran June 30th, 2015

Announcements

BASF and Fraunhofer IPMS-CNT jointly develop electronic materials June 30th, 2015

Graphene flexes its electronic muscles: Rice-led researchers calculate electrical properties of carbon cones, other shapes June 30th, 2015

Researchers from the UCA, key players in a pioneering study that may explain the origin of several digestive diseases June 30th, 2015

Oxford Instruments’ TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Nanobiotechnology

Nanometric sensor designed to detect herbicides can help diagnose multiple sclerosis June 23rd, 2015

Newly-Developed Biosensor in Iran Detects Cocaine Addiction June 23rd, 2015

Researchers first to show that Saharan silver ants can control electromagnetic waves over an extremely broad range of the electromagnetic spectrum—findings may lead to biologically inspired coatings for passive radiative cooling of objects June 19th, 2015

Cellulose from wood can be printed in 3-D June 17th, 2015

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