Go Ahead, Take a Jab at It

To be effective, some drugs must be administered transdermally. This may not be a problem for infrequently administered medications, like vaccines that can be given in a clinic. But when someone is living with a chronic condition that requires regular injections, a number of problems arise. Aside from the discomfort and inconvenience of regular hypodermic injections, there is a risk of transmitting bloodborne pathogens with each jab, and there are also concerns about the safe disposal of used syringes.

These drugs, like insulin for the treatment of diabetes, for example, can also be very dose-sensitive, with small variations having a large effect. The optimal dosage that is needed at any given time can vary based on a number of physiological factors, and adjustments may also need to be made as a condition progresses. This is generally not something that a patient can manage on their own — at least not with any meaningful level of precision.

For those that are living with diabetes, hyperlipidemia, asthma, depression, and many other conditions that are frequently treated with transdermal drugs, there are very few available options for precise, automated delivery of optimal doses. This leaves these individuals with sub-optimal medication administrations that decrease their effectiveness and increase the risk of unnecessary drug toxicity.

As for the automated drug delivery systems that do exist at present, they are limited in their ability to be digitally adjusted based on either sensor measurements or a doctor’s orders. Innovation in this space is sorely needed. Fortunately, a team led by researchers at the University of North Carolina at Chapel Hill have just delivered a very interesting solution. They have developed a flexible, wearable patch containing microneedles for drug delivery. This patch also has wireless communications and processing capabilities that allow it to deliver customized doses exactly when they are needed.

The patches contain many microneedles (in principle, they could contain hundreds), each capable of providing a precision dose of a specific drug. These microneedles are coated in a thin layer of gold that protects the needle and surrounding skin, and prevents the drugs from being administered. When a small amount of electrical current is passed through this gold coating, it will dissolve. This, in turn, exposes the needle and causes the medication to be administered.

To enable automated dosing, remote adjustments, and extended operation times, the devices contain a current regulator, a wireless energy harvester, a near-field communication module, and a microcontroller. After an external signal is received, the patch can deliver an injection within 30 seconds. Aside from just updating doses and schedules, this system can also be used to quickly deliver a drug in the event of a medical emergency.

Further testing and refinement will be needed before the patch can be used by humans, but the researchers have proved the utility of the device in an experiment with mice. In this experiment, the mice were fitted with patches that delivered injections of melatonin through the night. It was demonstrated that the mice receiving the melatonin had an improved quality of sleep, demonstrating the potential value of the device for clinical and research uses.

The team hopes that one day their drug delivery system will revolutionize the treatment of chronic conditions and minimize medical visits and hospital trips for these patients. They also intend to explore other diseases that this patch can be useful in treating, and experiment with using multiple patches where the administration of many drugs is required.