After binding DNA segments to tiny iron-containing spheres called nanoparticles, researchers have used magnetic fields to direct the nanoparticles into arterial muscle cells, where the DNA could have a therapeutic effect. Although the research, done in cell cultures, is in early stages, it may represent a new method for delivering gene therapy to benefit blood vessels damaged by arterial disease.
The nanoparticles are extremely small, ranging from 185 to 375 nanometers (a nanometer is one billionth of a meter, or a millionth of a millimeter). For comparison, red blood cells are ten to 100 times larger. The researchers were able to control the nanoparticle size by varying the amount or composition of solvents they used to form the nanoparticles.
The magnetically driven delivery system also may find broader use as a vehicle for delivering drugs, genes or cells to a target organ. “This is a novel delivery system, the first to use a biodegradable, magnetically driven polymer to achieve clinically relevant effects,” said study leader Robert J. Levy, M.D., the William J. Rashkind Chair of Pediatric Cardiology at The Children’s Hospital of Philadelphia. “This system has the potential to be a powerful tool.”
The proof-of-principle study, performed on vascular cells in culture, appears in the August issue of the FASEB Journal, published by the Federation of American Societies for Experimental Biology.
Impregnated with iron oxide, the nanoparticles carry a surface coating of DNA bound to an organic compound called polyethylenimine (PEI). The PEI protected the DNA from being broken down by enzymes called endonucleases that were present in the cell cultures and which occur normally in the bloodstream.
The DNA was in the form of a plasmid, a circular molecule that here carried a gene that coded for a growth-inhibiting protein called adiponectin. By applying a magnetic field, the study team steered the particles into arterial smooth muscle cells. Inside each cell, the DNA separated from the particle, entered the cell nucleus, and produced enough adiponectin to significantly reduce the proliferation of new cells.
In a practical application, such nanoparticles could be magnetically directed into stents, the tiny, expandable metal scaffolds inserted into a patient’s partially blocked vessels to improve blood flow. Many stents eventually fail as cells grow on their surfaces and create new obstructions, so delivering anti-growth genes to stents could help keep blood flowing freely.
The materials composing the nanoparticles are biodegradable, so they break down into simpler, nontoxic chemicals that can be carried away in the blood. “Previous researchers had shown that magnetically driven nanoparticles could deliver DNA in cell cultures, but ours is the first delivery system that is biodegradable, and therefore, safer to use in people,” said Levy.
“This delivery system may be a useful tool for delivering nonviral gene therapy, because it efficiently binds and protects DNA in blood serum and delivers it to cells,” added Levy. As a nonviral method, it avoids the unwanted immune system responses that have occurred when viruses are used to deliver gene therapy.
Levy said his team would pursue further studies into the feasibility of using the nanoparticles for gene therapy in blood vessels damaged by vascular disease. He suggested that the nanoparticles might find broader application, such as delivering gene therapy to tumors, or carrying drugs instead of or in addition to genes. Another possibility is that after preloading genetically engineered cells with nanoparticles, researchers could use magnetic forces to direct the cells to a target organ.
Furthermore, researchers might deliver nanoparticles to magnetically responsive, removable stents in sites other than blood vessels, such as airways or parts of the gastrointestinal tract. “We could remove the stent after the nanoparticles have delivered a sufficient number of genes, cells or other agents to have a long-lasting benefit,” he added.
John Ascenzi | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences