Navigation Links
Researchers use magnetism to target cells to animal arteries
Date:1/7/2008

Scientists have used magnetic fields and tiny iron-bearing particles to drive healthy cells to targeted sites in blood vessels. The research, done in animals, may lead to a new method of delivering cells and genes to repair injured or diseased organs in people.

The study team, led by Robert J. Levy, M.D., the William J. Rashkind Chair of Pediatric Cardiology at The Childrens Hospital of Philadelphia, loaded endothelial cells, flat cells that line the inside of blood vessels, with nanoparticles, tiny spheres nanometers in diameter. The nanoparticles contained iron oxide.

Using an external, uniform magnetic field, Levys team directed the cells into steel stents, small metal scaffolds that had been inserted into the carotid arteries of rats. The uniform magnetic field created magnetic gradients, local regions of high magnetic force that magnetized both the nanoparticles and the stents, thus increasing the attraction between the particles and their target.

The study appears in the Proceedings of the National Academy of Sciences, published online on Jan. 7. Dr. Levys group from Childrens Hospital collaborated with engineers from Drexel University and Duke University.

This is a novel strategy for delivering cells to targets in the body, said Levy, who added that previous researchers have pursued other, less successful approaches to introduce endothelial cells to diseased blood vessels, in the developing medical field of cell therapy.

Levys team created nanoparticles, approximately 290 nanometers across, made of the biodegradable polymer, polylactic acid, and impregnated with iron oxide. (A nanometer is a millionth of a millimeter; in comparison to these nanoparticles, red blood cells are ten to 100 times larger.)

The researchers loaded the nanoparticles into endothelial cells, which had been genetically modified to produce a specific color that could be detected by an imaging system while the animals were alive. After introducing stainless steel stents into rats carotid arteries, Levys team used magnetic fields to steer the cells into the stents.

Patients with heart disease commonly receive metal stents in partially blocked blood vessels to improve blood flow, both by widening the vessels and delivering drugs. However, many stents fail over time as smooth muscle cells accumulate excessively on their surfaces and create new blockages. One goal of cell therapy is to introduce new endothelial cells to recoat stents with a smooth surface.

Furthermore, Levy adds, while drug-releasing stents currently provide benefits in treating diseased coronary arteries, they have proved far less effective in treating peripheral vascular disease, such as that occurring in patients with diabetes. In such cases, severe problems in blood circulation may force doctors to amputate a leg. In upcoming animal studies, Levys team will use their delivery approach to deliver magnetic nanoparticles to peripheral arteries.

Future studies, Levy added, also will use cells derived from the animal itself, to avoid potential rejection problems that may occur with unmatched cells. The current study used unmatched cells, delivering bovine cells to rat arteries, but only over a 48-hour period, too brief for rejection to occur.

The current study builds on research published earlier this year by Levy and collaborators, in which they used magnetic fields and nanoparticles to deliver DNA to arterial muscle cells in culture. That research focused on a delivery system for gene therapy, while the current study represents cell therapy. Levy suggests future applications may combine both therapies, using endothelial cells to deliver beneficial genes to damaged arteries.

The delivery system, says Levy, might also be applied to other sites where physicians implant steel stents to deliver medication, such as the esophagus, bile ducts and lungs. Another potential use might be in orthopedic procedures, in which surgeons implant steel nails to stabilize fractured bones, or use steel screws to correct spinal abnormalities. In such cases, magnetized nanoparticles might deliver bone stem cells to strengthen bony structures.

Magnetic fields produced by ordinary MRI machines could suffice to deliver cells to targets where they could promote healing, since MRI uses uniform fields, which are key to our targeting strategy, added Levy. This method could become a powerful medical tool.


'/>"/>

Contact: John Ascenzi
Ascenzi@email.chop.edu
267-426-6055
Children's Hospital of Philadelphia
Source:Eurekalert  

Related biology technology :

1. Ames Laboratory researchers solve fuel-cell membrane structure conundrum
2. Researchers outline structure of largest nonvirus particle ever crystallized
3. UD researchers race ahead with latest spintronics achievement
4. ASU researchers improve memory devices using nanotech
5. Researchers underscore limitations of genetic ancestry tests
6. Researchers measure carbon nanotube interaction
7. Stevens researchers provide new information about mass spectrometry
8. CU researchers shed light on light-emitting nanodevice
9. Long-awaited international ethical guidelines for biobank researchers
10. Researchers improve ability to write and store information on electronic devices
11. Sirnaomics Received Multiple Government Fundings For Its Multi-Targeted siRNA Therapeutics Programs
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Researchers use magnetism to target cells to animal arteries
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building ... corporate rebranding initiative announced today. The bold new look is part of a ... company moves into a significant growth period. , It will also expand its service ...
(Date:10/10/2017)... , Oct. 10, 2017 International research firm Parks Associates ... will speak at the TMA 2017 Annual Meeting , October 11 ... in the residential home security market and how smart safety and security ... Parks Associates: ... "The residential security ...
(Date:10/9/2017)... 9, 2017  BioTech Holdings announced today identification ... its ProCell stem cell therapy prevents limb loss ... Company, demonstrated that treatment with ProCell resulted in ... as compared to standard bone marrow stem cell ... in reduction of therapeutic effect.  ...
(Date:10/9/2017)... Texas (PRWEB) , ... October ... ... study published on October 5, 2017, in the medical journal, Epilepsia, Brain ... with the gold standard, video EEG, in detecting generalized tonic-clonic seizures (GTCS) ...
Breaking Biology Technology:
(Date:4/4/2017)... 2017   EyeLock LLC , a leader of ... States Patent and Trademark Office (USPTO) has issued U.S. ... of an iris image with a face image acquired ... company,s 45 th issued patent. ... given the multi-modal biometric capabilities that have recently come ...
(Date:3/30/2017)... March 30, 2017  On April 6-7, 2017, Sequencing.com ... Genome hackathon at Microsoft,s headquarters in ... will focus on developing health and wellness apps that ... Hack the Genome is the first hackathon for ... world,s largest companies in the genomics, tech and health ...
(Date:3/30/2017)... YORK , March 30, 2017 Trends, ... type (physiological and behavioral), by technology (fingerprint, AFIS, iris ... voice recognition, and others), by end use industry (government ... and immigration, financial and banking, and others), and by ... Europe , Asia Pacific , ...
Breaking Biology News(10 mins):