Understanding how cells respond to nanoparticles

Oct 28, 2010

Gold nanoparticles are showing real promise as vehicles for efficiently delivering therapeutic nucleic acids, such as disease-fighting genes and small interfering RNA (siRNA) molecules, to tumors. Now, a team of investigators from Northwestern University has shown that the safety of gold nanoparticle-nucleic acid formulations depends significantly on how the nucleic acids and nanoparticles are linked to one another, a finding with important implications for those researchers developing such constructs.

Chad Mirkin, co-principal investigator of the Northwestern University Center for Cancer Nanotechnology Excellence, one of nice such centers established by the National Cancer Institute (NCI), led the team of investigators that studied how cells respond to different nucleic acid-nanoparticle formulations. The investigators published their results in the journal ACS Nano.

To measure how cancer cells respond when they take up nanoparticles, Dr. Mirkin and his colleagues used a technique known as genome-wide expression profiling, which measures relative changes in global . The investigators added different types of nanoparticles to growing in culture dishes and then obtained whole genome expression profiles for the cells. In all the experiments, the researchers attached non-targeting nucleic acids attached to the nanoparticles in order to minimize gene changes that might be triggered through a therapeutic effect relating to a specific, designed interaction between the nucleic acid and a targeted gene.

The results of these comparison studies showed that the surface properties of the nanoparticles had a profound impact on how a given nanoparticle impacts gene expression within a cell. The researchers observed the most surprising and noteworthy difference when they compared two nanoparticles that differed only in the manner in which the nucleic acids were attached to the nanoparticle surface. Nanoparticles loosely linked to the nucleic acids triggered large-scale changes in gene expression, while in contrast, nanoparticles linked tightly to through a covalent chemical bond had virtually no effect on gene expression. These findings, the researchers noted, show how important it is to fully characterize nanoparticles not only in terms of the shape and size, but also with respect to their surface properties.

Explore further: Nano-scale gold particles are good candidates for drug delivery

More information: This work is detailed in a paper titled, "Cellular Response of Polyvalent Oligonucleotide-Gold Nanoparticle Conjugates."

Related Stories

Pack 'Em In -- Gold Nanoparticles Improve Gene Regulation

Feb 23, 2009

Investigators at Northwestern University have found that packing small interfering RNA (siRNA) molecules onto the surface of a gold nanoparticle can protect siRNAs from degradation and increase their ability to regulate genes ...

Gold Nanoparticles Delivery Platinum Warheads to Tumors

Oct 29, 2009

(PhysOrg.com) -- Cisplatin is one of the most powerful and effective drugs for treating a wide variety of cancers, but serious side effects ultimately limit the drug's use and effectiveness. Now, however, researchers have ...

Biobarcode Nanoparticles Enable Multiplexed DNA Detection

Jun 01, 2006

Given that cancer is a disease that results from gene mutations, the development of high-throughput schemes for detecting specific DNA sequences would have a dramatic effect on cancer research, cancer detection, and the monitoring ...

Magnetic Nanoworms and Nanocrystals Deliver siRNA to Tumors

Sep 23, 2009

(PhysOrg.com) -- 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 ...

Self-Assembling Nanoparticles Image Tumor Cells

Jul 23, 2007

By taking advantage of the full range of ways in which molecules can interact with and bind to one another, a team of investigators at the Carolina Center of Cancer Nanotechnology Excellence has created nanoparticles that ...

Recommended for you

Graphene surfaces on photonic racetracks

7 hours ago

In an article published in Optics Express, scientists from The University of Manchester describe how graphene can be wrapped around a silicon wire, or waveguide, and modify the transmission of light through it.

Simulating the invisible

7 hours ago

Panagiotis Grammatikopoulos in the OIST Nanoparticles by Design Unit simulates the interactions of particles that are too small to see, and too complicated to visualize. In order to study the particles' behavior, he uses ...

Building 'invisible' materials with light

8 hours ago

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

User comments : 0