Navigation Links
Using magnetism to turn drugs on and off

Many medical conditions, such as chronic pain, cancer and diabetes, require medications that cannot be taken orally, but must be dosed intermittently, on an as-needed basis, over a long period of time. A few delivery techniques have been developed, using an implanted heat source, an implanted electronic chip or other stimuli as an "on-off" switch to release the drugs into the body. But thus far, none of these methods can reliably do all that's needed: repeatedly turn dosing on and off, deliver consistent doses and adjust doses according to the patient's need.

Researchers led by Daniel Kohane, MD, PhD of Children's Hospital Boston, funded by the National Institutes of Health, have devised a solution that combines magnetism with nanotechnology.

The team created a small implantable device, less than " in diameter, that encapsulates the drug in a specially engineered membrane, embedded with nanoparticles (approximately 1/100,000 the width of a human hair) composed of magnetite, a mineral with natural magnetic properties. When a magnetic field is switched on outside the body, near the device, the nanoparticles heat up, causing the gels in the membrane to warm and temporarily collapse. This opens up pores that allow the drug to pass through and into the body. When the magnetic force is turned off, the membranes cool and the gels re-expand, closing the pores back up and halting drug delivery. No implanted electronics are required.

The device, which Kohane's team is continuing to develop for clinical use, is described in the journal Nano Letters (published online September 8, DOI: 10.1021/nl9018935).

"A device of this kind would allow patients or their physicians to determine exactly when drugs are delivered, and in what quantities," says Kohane, who directs the Laboratory for Biomaterials and Drug Delivery in the Department of Anesthesiology at Children's.

In animal experiments, the membranes remained functional over multiple cycles. The size of the dose was controllable by the duration of the "on" pulse, and the rate of release remained steady, even 45 days after implantation.

Testing indicated that drug delivery could be turned on with only a 1 to 2 minute time lag before drug release, and turned off with a 5 to 10 minute time lag. The membranes remained mechanically stable under tensile and compression testing, indicating their durability, showed no toxicity to cells, and were not rejected by the animals' immune systems. They are activated by temperatures higher than normal body temperatures, so would not be affected by the heat of a patient's fever or inflammation.

"This novel approach to drug delivery using engineered 'smart' nanoparticles appears to overcome a number of limitations facing current methods of delivering medicines," says Alison Cole, Ph.D., who oversees anesthesia grants at the National Institutes of Health's National Institute of General Medical Sciences (NIGMS). "While some distance away from use in humans, this technology has the potential to provide precise, repeated, long-term, on-demand delivery of drugs for a number of medical applications, including the management of pain."


Contact: James Newton
Children's Hospital Boston

Related biology news :

1. U of M begins nations first clinical trial using T-reg cells from cord blood in leukemia treatment
2. Fever causing headaches for Aussie parents
3. Using evolution, UW team creates a template for many new therapeutic agents
4. Using green chemistry to deliver cutting-edge drugs
5. IGERT fellows to design biodevices using flexible electronics
6. Prediction of RNA pseudoknots using heuristic modeling with mapping and sequential folding
7. Computer program traces ancestry using anonymous DNA samples
8. Using nanotubes to detect and repair cracks in aircraft wings, other structures
9. Book on weeds and invasive plants discusses how to manage them using ecological approaches
10. Study shows housing development on the rise near national forests
11. Rare cancer-causing syndrome found, for the first time, in Singapore
Post Your Comments:
(Date:6/22/2016)...  The American College of Medical Genetics and Genomics was ... as one of the fastest-growing trade shows during the Fastest ... in Las Vegas . ... in each of the following categories: net square feet of ... attendees. The 2015 ACMG Annual Meeting was ranked 23 out ...
(Date:6/22/2016)... 22, 2016 On Monday, the Department of ... to share solutions for the Biometric Exit Program. The ... Border Protection (CBP), explains that CBP intends to add ... the United States , in order to ... imposters. Logo - ...
(Date:6/20/2016)... 2016 Securus Technologies, a leading provider ... public safety, investigation, corrections and monitoring announced that ... has secured the final acceptance by all three ... Access Systems (MAS) installed. Furthermore, Securus will have ... installed by October, 2016. MAS distinguishes between legitimate ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016   EpiBiome , a ... $1 million in debt financing from Silicon Valley Bank ... automation and to advance its drug development efforts, as ... facility. "SVB has been an incredible strategic ... services a traditional bank would provide," said Dr. ...
(Date:6/23/2016)... OTTAWA, ON (PRWEB) , ... June 23, 2016 , ... ... former DNA Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA ... joining the STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. ...
(Date:6/23/2016)... , June 23, 2016 Apellis ... Phase 1 clinical trials of its complement C3 ... single and multiple ascending dose studies designed to ... (PD) of subcutaneous injection in healthy adult volunteers. ... (SC) either as a single dose (ranging from ...
(Date:6/23/2016)... 23, 2016 Andrew ... Published recently in ... journal from touchONCOLOGY, Andrew D Zelenetz , ... cancer care is placing an increasing burden on ... biologic therapies. With the patents on many biologics ...
Breaking Biology Technology: