Drug Delivery Method Introduced Using Magnetism and Nanotechnology

A new solution to deliver drugs into the body more effectively has been devised using magnetism and nanotechnology.

In order to deliver drugs into the body effectively for various medical conditions such as diabetes, cancer and chronic pain, delivering consistent dosage, which could be adjusted, and delivery of this could be turned on and off, according to patient requirements. This should be possible over a longer period of time. Especially, apt where medications for such conditions cannot be taken orally.

Currently, there are several delivery methods that are being used that attempt to move closer to the ideal delivery. These include an implanted electronic chip, an implanted heat source and other techniques that release drugs into the body intermittently.

Researchers at Children’s Hospital Boston, led by Daniel Kohane, MD, PhD, Associate Professor of Anesthesiology, have now found a solution to more effective drug delivery that utilizes magnetism and nanotechnology. The team collaborated with Robert Langer of the Massachusetts Institute of Technology and MIT-Harvard Center for Cancer Nanotechnology Excellence, and the McMaster University and the University of Zaragoza.

Findings are described in their paper titled ‘A Magnetically Triggered Composite Membrane for On-Demand Drug Delivery’ published in the peer-reviewed scientific journal Nano Letters.

Researchers developed a small implantable device, less than one centimeter in diameter, that encapsulates a drug in a specially engineered membrane, embedded with magnetic iron oxide nanoparticles.

The magnetic nanoparticles are then heated with an external alternating magnetic field that causes the gels in the membrane to warm up and temporarily subside. Drugs are then able to pass through into the body. Once the magnetic field is then turned off the membranes cool back down and the gel expands and closes the pores ending the drug delivery. Electronics do not need to be implanted as the field is generated from outside the body. This process can then be repeated when the next drug delivery is scheduled.

The size of the dose released into the body can be controlled based on the time the magnetic device is turned on, so the rate of release is consistent over multiple deliveries. Once the device is turned on it took about one to two minutes before the drug was released and then a five to 10 minute delay to end delivery once the device was turned off.

During tensile and compression testing of the membranes to determine durability, results showed the membranes were mechanically stable. Tests showed no toxicity to cells and were not rejected by the immune system in a rate model. The membranes remained functional after 45 days in vitro. To activate the membranes a heat level higher than the body’s normal temperatures is used so there would be no affect from local inflammation or fever in the patient.