Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

The Gold Standard for Cell Penetration

Published: Friday, August 23, 2013
Last Updated: Friday, August 23, 2013
Bookmark and Share
Gold nanoparticles with special coatings can deliver drugs or biosensors to a cell’s interior without damaging it.

Cells are very good at protecting their precious contents — and as a result, it’s very difficult to penetrate their membrane walls to deliver drugs, nutrients or biosensors without damaging or destroying the cell. One effective way of doing so, discovered in 2008, is to use nanoparticles of pure gold, coated with a thin layer of a special polymer. But nobody knew exactly why this combination worked so well, or how it made it through the cell wall.

Now, researchers at MIT and the Ecole Polytechnique de Lausanne in Switzerland have figured out how the process works, and the limits on the sizes of particles that can be used. Their analysis appears in the journal Nano Letters, in a paper by graduate students Reid Van Lehn, Prabhani Atukorale, Yu-Sang Yang and Randy Carney and professors Alfredo Alexander-Katz, Darrell Irvine and Francesco Stellacci.

Until now, says Van Lehn, the paper’s lead author, “the mechanism was unknown. … In this work, we wanted to simplify the process and understand the forces” that allow gold nanoparticles to penetrate cell walls without permanently damaging the membranes or rupturing the cells. The researchers did so through a combination of lab experiments and computer simulations.

The team demonstrated that the crucial first step in the process is for coated gold nanoparticles to fuse with the lipids — a category of natural fats, waxes and vitamins — that form the cell wall. The scientists also demonstrated an upper limit on the size of such particles that can penetrate the cell wall — a limit that depends on the composition of the particle’s coating.

The coating applied to the gold particles consists of a mix of hydrophobic and hydrophilic components that form a monolayer — a layer just one molecule thick — on the particle’s surface. Any of several different compounds can be used, the researchers explain.

“Cells tend to engulf things on the surface,” says Alexander-Katz, an associate professor of materials science and engineering at MIT, but it’s “very unusual” for materials to cross that membrane into the cell’s interior without causing major damage. Irvine and Stellacci demonstrated in 2008 that monolayer-coated gold nanoparticles could do so; they have since been working to better understand why and how that works.

Since the nanoparticles themselves are completely coated, the fact that they are made of gold doesn’t have any direct effect, except that gold nanoparticles are an easily prepared model system, the researchers say. However, there is some evidence that the gold particles have therapeutic properties, which could be a side benefit.

Gold particles are also very good at capturing X-rays — so if they could be made to penetrate cancer cells, and were then heated by a beam of X-rays, they could destroy those cells from within. “So the fact that it’s gold may be useful,” says Irvine, a professor of materials science and engineering and biological engineering and member of the Koch Institute for Integrative Cancer Research.

Significantly, the mechanism that allows the nanoparticles to pass through the membrane seems also to seal the opening as soon as the particle has passed. “They would go through without allowing even small molecules to leak through behind them,” Van Lehn says.

Irvine says that his lab is also interested in harnessing this cell-penetrating mechanism as a way of delivering drugs to the cell’s interior, by binding them to the surface coating material. One important step in making that a useful process, he says, is finding ways to allow the nanoparticle coatings to be selective about what types of cells they attach to. “If it’s all cells, that’s not very useful,” he says, but if the coatings can be targeted to a particular cell type that is the target of a drug, that could be a significant benefit.

Another potential application of this work could be in attaching or inserting biosensing molecules on or into certain cells, Van Lehn says. In this way, scientists could detect or monitor specific biochemical markers, such as proteins that indicate the onset or decline of a disease or a metabolic process.

In general, attachment to nanoparticles’ surface coatings could provide a key to cells’ interiors for “molecules that normally wouldn’t have any ability to get through the cell membrane,” Irvine says.

Vince Rotello, a professor of chemistry at the University of Massachusetts at Amherst who was not involved in this research, says this work is “careful, well thought out and elegantly presented.” He adds, “This study provides a very interesting alternative mechanism to cell uptake of nanomaterials that could open up new therapeutic pathways.”

The work was supported by the National Science Foundation, the National Cancer Institute and the U.S. Army Research Office.


Further Information

Join For Free

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 3,300+ scientific posters on ePosters
  • More Than 4,900+ 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 TechnologyNetworks.com 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

Targeting Neglected Diseases
New enzyme-mapping advancement could help drug development for combating diseases in the developing world.
Wednesday, August 17, 2016
Protecting Privacy in Genomic Databases
System helps ensure databases used in medical research will not leak patients’ personal information.
Wednesday, August 10, 2016
Biopharmaceuticals on Demand
Portable production system would use microbes for manufacturing small amounts of vaccines and therapeutics.
Monday, August 01, 2016
Triple-Action Therapy Patch Shows Promise
Patch that delivers drug, gene, and light-based therapy to tumor sites shows promising results in mice.
Wednesday, July 27, 2016
New Device can Study Electric Field Cancer Therapy
Microfluidic device allows study of electric field cancer therapy through low-intensity fields, preventing malignant cells spreading.
Friday, July 08, 2016
Programmable RNA Vaccines
Tests in mice show the vaccines work against Ebola, influenza, and a common parasite.
Wednesday, July 06, 2016
Seeing RNA at the Nanoscale
MIT researchers have developed a new way to image proteins and RNA inside neurons of brain tissue.
Wednesday, July 06, 2016
Tough New Hydrogel Hybrid Doesn’t Dry Out
Water-based material could be used to make artificial skin, longer-lasting contact lenses.
Friday, July 01, 2016
Wireless, Wearable Toxic-Gas Detector
Inexpensive sensors could be worn by soldiers to detect hazardous chemical agents.
Friday, July 01, 2016
New System for Detecting Explosives
Spectroscopic system with chip-scale lasers cuts detection time from minutes to microseconds.
Wednesday, June 01, 2016
Illuminating Hidden Gene Regulators
New super-resolution technique visualizes important role of short-lived enzyme clusters.
Friday, May 27, 2016
Controlling RNA in Living Cells
Modular, programmable proteins can be used to track or manipulate gene expression.
Wednesday, April 27, 2016
Long-Term Drug Release
New tablet attaches to the lining of the GI tract, resists being pulled away.
Thursday, April 07, 2016
Pharmacy on Demand
New, portable system can be configured to produce different drugs.
Monday, April 04, 2016
A Programming Language for Living Cells
New language lets researchers design novel biological circuits.
Monday, April 04, 2016
Scientific News
Shedding Light on HIV Vaccine Design
Broadly speaking - Mathematical modelling of host-pathogen coevolution sheds light on HIV vaccine design.
AACC 2016 Sees Clinical Chemistry Labs Drive Precision Medicine Offerings
Biomarker assays to enable precision medicine and risk assessment, mass spec-based tests designed for use in clinical labs large and small, and liquid biopsy technology captured the spotlight at the AACC annual meeting.
Automated Patch Clamping Trends
Learn more about current practices, preferences and metrics in ion channel drug screening using APC technology.
Lab-on-a-Stick: Miniaturised Clinical Testing For Fast Detection Of Antibiotic Resistance
A portable power-free test for the rapid detection of bacterial resistance to antibiotics has been developed by academics at Loughborough University and the University of Reading.
Genetic Ancestry of Cultivated Strawberry Unravelled
UNH scientists constructed a linkage map of the seven chromosomes of the diploid Fragaria iinumae, which allows them to fill in a piece of the genetic puzzle about the eight sets of chromosomes of the cultivated strawberry.
Progress In Vaccination Against Vespid Venom
Researchers at the Helmholtz Zentrum München and the Technical University Munich have presented a method which facilitates a personalised procedure for wasp allergy sufferers.
New Drug Target for Inflammatory Disorders
Penn study finds enigmatic molecules maintain equilibrium between fighting infection and inflammatory havoc.
Breast Cancer Cells Found To Switch Molecular Characteristics
Spontaneous interconversion between HER2-positive and HER2-negative states could contribute to progression, treatment resistance in breast cancer.
Mechanisms of Calcium Blockers
Researchers describe how the fundamental mode of action of two distinct chemical classes of calcium channel blockers differs.
Some Breast Cancer Patients With Low Genetic Risk Could Skip Chemotherapy
Genetic test can help predict survival and guide treatment options.
Scroll Up
Scroll Down
Skyscraper Banner

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
3,300+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,900+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!