Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

Nano Compartments May Aid Drug Delivery, Catalyst Design

Published: Monday, April 22, 2013
Last Updated: Monday, April 22, 2013
Bookmark and Share
Spongelike nanoparticles whose pores can be filled with drugs offer the promise of drug delivery to specific targets in the body, avoiding unpleasant side effects.

Cornell researchers have now created nanoparticles with separate compartments that could carry two or more different drugs to the same location, with precise control over the amounts. The technology might also be applied to catalysts used to enhance chemical reactions, which are sometimes formed into porous nanoparticles to expose more surface area; compartmented particles could allow two or more catalysts to work in sequence.

Ulrich Wiesner, the Spencer T. Olin Professor of Materials Science and Engineering, and first authors, Cornell researcher Teeraporn Suteewong and graduate student Hiroaki Sai, have tweaked familiar “sol-gel” chemistry used to self-assemble porous silica particles, making the assembly shift gears partway through to create what amounts to two or more different nanoparticles joined together, while controlling how one particle grows out of another, a process referred to as epitaxial growth.

“It’s the first time I’m aware of that the shapes of porous silica nanoparticles have been controlled via epitaxy,” Wiesner said. “The cubic lattice and the hexagonal lattice have a well-defined relationship.” The products so far are fairly simple particles with two or three compartments, but the methods might be extended to create much more complex structures, he said.

The discovery was partly serendipitous. While making ordinary nanoparticles, the scientists saw a small fraction with hexagonally structured porous branches growing out of a cubic core particle. “We set out to understand what controls that,” Wiesner said.

Wiesner’s team and researchers from Memorial Sloan Kettering Cancer Center in New York City report their results in the April 19 issue of the journal Science as “Multicompartment Mesoporous Silica Nanoparticles with Branched Shapes: An Epitaxial Growth Mechanism.” The other researchers include graduate student Robert Hovden; David Muller, professor of applied and engineering physics; Sol M. Gruner, professor of physics; and Michelle Bradbury, M.D., Ph.D., Memorial Sloan-Kettering Cancer Center.

The starter for the process is a mixture of organosilanes, molecules built around carbon and silicon atoms, and surfactants. Surfactants, of which the prime example is soap, have one end that likes water and another “oily” end that tries to stay away from it. So in water surfactants form micelles, tiny spherical bundles with the water-loving end out and the oily part tucked away in the center. In the sol-gel process the micelles act as cages around which silica from the orgaosilanes forms, building particles about a hundred nanometers in diameter. When the micelles are washed away what remains is a porous silica structure with pores two to three nanometers in size. “The micelles are placeholders for the pores,” Wiesner explained. (A nanometer is a billionth of a meter, about the length of three atoms in a row.)

The type of pore lattice depends, among other things, on the pH, or acidity, of the solution. The researchers added ethyl acetate, a chemical that breaks down in water and in the process makes the solution more acidic, to act as a timer to change the output of the reaction partway through. At first a cubic lattice forms, building cubical particles. As acidity increases the reaction path changes to make a hexagonal lattice creating cylinders that begin to grow out of the faces of the cubes. The number of cylinders and their length can be controlled by the concentration of ethyl acetate, generating tripods or even tetrapods.

“Previous work in my group and that of others has focused on how to control the pore structure,“ Wiesner said. “Here we use the pore structure to control the shape of the nanoparticles.”

In a hint of the future, the researchers were able to connect two or three cubes with cylindrical bridges between them, perhaps the beginning of a network of cubes and tubes like a nanoscale hamster habitat. “We have learned to switch the growth conditions. If we can switch back we might be able to grow all sorts of funky architectures,” Wiesner said.

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,600+ scientific posters on ePosters
  • More than 3,800+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Tumor-suppressing Gene Lends Insight to Cancer Treatment
Researchers have found that delicate replication process derails if a gene named PTEN has mutated or is absent.
Tuesday, July 14, 2015
Computer Model Reveals Cancer's Energy Source
Findings focused on the energy-making process in cancer cells known as the Warburg Effect.
Tuesday, August 19, 2014
For Cancer Patients, Sugar-Coated Cells are Deadly
Paszek’s lab will focus on developing high-resolution microscopy to further study cell membrane-related cancer mechanisms.
Friday, June 27, 2014
Gold-Plated Nano-Bits Find, Destroy Cancer Cells
Scientists have merged tiny gold and iron oxide particles, then added antibody guides to steer them through the bloodstream toward colorectal cancer cells.
Monday, October 21, 2013
Genetic Switches Play Big Role in Human Evolution
Study offers further proof that the divergence of humans from chimpanzees was profoundly influenced by mutations to DNA sequences.
Wednesday, June 12, 2013
Turn out the Light: 'Switch' Determines Cancer Cell Fate
Like picking a career or a movie, cells have to make decisions – and cancer results from cells making wrong decisions.
Friday, May 03, 2013
Scientists Develop World's Smallest Drug Deliverer
Cornell researchers have created a pore in “Cornell Dots” – brightly glowing nanoparticles nicknamed C-Dots – that can carry medicine.
Friday, April 12, 2013
DNA Editor Named Runner-up Breakthrough of 2012
A discovery that allows life scientists to precisely edit genomes for everything from crop and livestock improvement to human gene and cell therapy was named runner-up for Science magazine's 2012 Breakthrough of the Year.
Wednesday, February 27, 2013
Organic Metamaterial Flows like a Liquid, Remembers its Shape
A bit reminiscent of the Terminator T-1000, a new material created by Cornell researchers is so soft that it can flow like a liquid and then, strangely, return to its original shape.
Tuesday, December 04, 2012
Study: How Cells form 'Trash Bags' for Recycling Waste
A class of membrane-sculpting proteins create vesicles that carry old and damaged proteins from the surface of cellular compartments into internal recycling plants where the waste is degraded and components are reused.
Tuesday, October 23, 2012
Metastatic 'Switch' Sheds New Light on Colon Cancer
What kills cancer patients often isn't the primary tumor; it's when the tumor metastasizes - or spreads the cancer to other areas of the body.
Tuesday, September 11, 2012
The Force is with us: GEDI Chip Sorts Prostate Cancer Cells
Geometrically Enhanced Differential Immunocapture chip identify and collect cancer cells from a patient's bloodstream.
Friday, June 29, 2012
Some Stem Cells Can Trigger Tumors
When in contact with even trace amounts of cancer cells, stem cells can create a microenvironment suitable for more tumors to grow.
Wednesday, June 06, 2012
Scientific News
Researchers Develop Classification Model for Cancers Caused by KRAS
Most frequently mutated cancer gene help oncologists choose more effective cancer therapies.
Tolerant Immune System Increases Cancer Risk
Researchers have found that individuals with high immunoCRIT ratios may have an increased risk of developing certain cancers.
Developing a Gel that Mimics Human Breast for Cancer Research
Scientists at the Universities of Manchester and Nottingham have been funded to develop a gel that will match many of the biological structures of human breast tissue, to advance cancer research and reduce animal testing.
New Gene Therapy for Vision Loss From a Mitochondrial Disease
NIH-funded study shows success in targeting mitochondrial DNA in mice.
Predictive Model for Breast Cancer Progression
Biomedical engineers have demonstrated a proof-of-principle technique that could give women and their oncologists more personalized information to help them choose options for treating breast cancer.
Specific Variations in RNA Splicing Linked to Breast Cancer
Researchers have identified cellular changes that may play a role in converting normal breast cells into tumors. Targeting these changes could potentially lead to therapies for some forms of breast cancer.
Gene Expression: A Snapshot of Stem Cell Development
New genes found that regulate development of stem cells.
Assessing Cancer Patient Survival and Drug Sensitivity
RNA editing events another way to investigate biomarkers and therapy targets.
Editing Genes to Create HIV Killers
Seattle scientists have managed to genetically transform human cells in the lab from HIV targets to HIV killers, and the technique could have implications for cancer and other diseases.
Researchers Disguise Drugs As Platelets to Target Cancer
Researchers have for the first time developed a technique that coats anticancer drugs in membranes made from a patient’s own platelets.

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,600+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos