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

Nanoparticles, 'pH Phoresis' Could Improve Cancer Drug Delivery

Published: Wednesday, July 10, 2013
Last Updated: Wednesday, July 10, 2013
Bookmark and Share
Researchers have developed a concept to potentially improve delivery of drugs for cancer treatment using nanoparticles.

The concept involves using nanoparticles made of "weak polybases," compounds that expand when transported into environments mimicking tumor cells, which have a higher acidity than surrounding tissues. The researchers used sophisticated modeling to show how the particles would accumulate in regions of higher acidity and remain there long enough to delivery anticancer drugs.

"This phenomenon, which we term pH phoresis, may provide a useful mechanism for improving the delivery of drugs to cancer cells in solid tumor tissues," said You-Yeon Won, an associate professor of chemical engineering at Purdue University.

Solutions with a pH less than 7 are said to be acidic, and those with a higher pH are basic or alkaline. The pH phoresis concept hinges on using synthetic "polymer micelles," tiny drug-delivery spheres that harbor medications in their inner core and contain an outer shell made of a material that has been shown to expand dramatically as the pH changes from alkaline to acidic.

A twofold size increase could result in a similar increase in the efficiency of drug delivery to tumors.

"Such an effect would be a game changer by delivering the proper dose of anticancer drugs inside tumor cells," Won said. "This pH phoresis concept also could be combined readily within other established drug-delivery methodologies, making it potentially practical for medical application."

The concept is described in a research paper that will appear in the Journal of Controlled Release on July 15, and an unedited version appeared online June 19. The paper was written by Won and doctoral student Hoyoung Lee. Findings showed how the micelles' expansion is optimized in the specific pH in tumor cells.

The researchers demonstrated that the highest degree of micelle swelling in tumors needs to occur when there is a pH of about 7.0, plus or minus 0.5, for optimal delivery of drugs to tumor tissue.

"Solid tumors have a significantly lower extracellular pH, about 6.5-6.9, compared to normal tissue, which has an average pH of 7.4," Won said.

The weak polybases in the micelles contain molecules called amines, which are made of nitrogen and hydrogen atoms. The micelles swell at lower pH due to the increased "protonation," or the addition of protons to nitrogen atoms in the amines. Because the protons are positively charged, the like-charged amines repel each other, causing the nanoparticles to expand.

The positive charge slows the movement of micelles out of tumor tissue, which would cause the nanoparticles to accumulate inside the tumor mass long enough to enter tumor cells and release anticancer drugs.

"This concept is straightforward to understand, yet no one recognized it previously," Won said. "And it took us a while to put this description on a mathematical footing. To do that, we had to modify the famous Fick's first law diffusion equation."

The law, derived by physician and physiologist Adolf Fick in 1855, describes how molecules diffuse from regions of high concentration to regions of low concentration.

The micelles also are coated with protective varnish so that they might remain intact long enough to reach tumor sites, where they would expand and then biodegrade.

More research is needed to determine how well the approach could enhance drug delivery, but the pH phoresis concept developed by Won and his student represents a step in developing nanomedicine techniques in drug delivery, he said.


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 2,900+ scientific posters on ePosters
  • More than 4,200+ 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

Remote-Controlled Drug Delivery
A team of researchers has created a new implantable drug-delivery system using nanowires that can be wirelessly controlled.
Thursday, June 25, 2015
Mass Spectrometry Tool Helps Guide Brain Cancer Surgery
A tool to help brain surgeons test and more precisely remove cancerous tissue was successfully used during surgery, according to a Purdue University and Brigham and Women's Hospital study.
Wednesday, July 02, 2014
Cell-Detection System Promising for Medical Research, Diagnostics
Researchers are developing a system that uses tiny magnetic beads to quickly detect rare types of cancer cells circulating in a patient's blood.
Thursday, October 03, 2013
Purdue Innovation could Improve Personalized Cancer-Care Outcomes
An innovation could improve therapy selection for personalized cancer care by helping specialists better identify the most effective drug treatment combinations for patients.
Friday, August 16, 2013
New Imaging Technology Could Reveal Cellular Secrets
Researchers have married two biological imaging technologies, creating a new way to learn how good cells go bad.
Friday, April 26, 2013
MolecularHUB Gives Scientific Information on Fast-moving Diseases
A scientific gateway website that will provide molecular and genetic information on infectious and emerging diseases has been released by Purdue University.
Thursday, October 25, 2012
Body Heat, Fermentation Drive New Drug-Delivery 'Micropump'
Researchers have created a new type of miniature pump activated by body heat that could be used in drug-delivery patches powered by fermentation.
Friday, September 14, 2012
Gene's function May Give New Target for Cancer Drugs
Scientists have determined that a gene long known to be involved in cancer cell formation and chemotherapy resistance is key to proper RNA creation, and could one day lead to new therapies and drug targets.
Thursday, September 13, 2012
Imaging Tool Tracks Carbon Nanotubes in Living Cells
Researchers have demonstrated a new imaging tool for tracking structures called carbon nanotubes in living cells and the bloodstream, which could aid efforts to perfect their use in biomedical research and clinical medicine.
Thursday, December 08, 2011
Kylin Therapeutics Licenses an RNAi Delivery Technology from Purdue University
Kylin has signed exclusive license agreement that include more than 12 patent applications covering pRNA with Purdue University.
Monday, July 09, 2007
Purdue Scientists Treat Cancer with RNA Nanotechnology
Microscopic particles possess both the right size to gain entry into cells and also the right structure to carry other therapeutic strands of RNA inside with them.
Tuesday, September 20, 2005
Scientific News
NIH Researchers Identify Striking Genomic Signature for Cancer
Institute has identified striking signature shared by five types of cancer.
CRI Develops Innovative Approach for Identifying Lung Cancer
Institute has developed innovative approach for identifying processes that fuel tumor growth in lung cancer patients.
Counting Cancer-busting Oxygen Molecules
Researchers from the Centre for Nanoscale BioPhotonics (CNBP), an Australian Research Centre of Excellence, have shown that nanoparticles used in combination with X-rays, are a viable method for killing cancer cells deep within the living body.
Crowdfunding the Fight Against Cancer
From budding social causes to groundbreaking businesses to the next big band, crowdfunding has helped connect countless worthy projects with like-minded people willing to support their efforts, even in small ways. But could crowdfunding help fight cancer?
Cancer Cells Kill Off Healthy Neighbours
Cancer cells create space to grow by killing off surrounding healthy cells, according to UK researchers working with fruit flies.
Cancer Drug Target Visualized at Atomic Resolution
New study using cryo-electron microscopy shows how potential drugs could inhibit cancer.
Genetic Mechanism Behind Cancer-Causing Mutations
Researchers at Indiana University has identified a genetic mechanism that is likely to drive mutations that can lead to cancer.
Future of Medicine Could be Found in a Tiny Crystal Ball
A Drexel University materials scientist has discovered a way to grow a crystal ball in a lab. Not the kind that soothsayers use to predict the future, but a microscopic version that could be used to encapsulate medication in a way that would allow it to deliver its curative payload more effectively inside the body.
"Gene Fusion" Drives Childhood Brain Cancers
Study co-led by Penn scientists highlights potential targets for future cancer therapies.
Enzyme Links Age-Related Inflammation, Cancer
Researchers have shown that an enzyme key to regulating gene expression -- and also an oncogene when mutated -- is critical for the expression of numerous inflammatory compounds that have been implicated in age-related increases in cancer and tissue degeneration.
SELECTBIO

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
2,900+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,200+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!