Drugs are used in numerous medical applications, such as improving the patency of a stent, cancer treatment, and infection control. Although drugs are used to treat an injury or alleviate pain, many of them will have adverse side effects if the drug is administered systemically (throughout the entire body). Once drugs are administered, they are nonlinearly absorbed into the body and result in only acute (short term) effects. For this reason, a method of chronic (long-lasting or long-term) and localized drug delivery would be advantageous to treating the area of interest without causing adverse systemic effect. The two main variables that need to be controlled are drug dosage and timed release of the drug. Many methods, such as polymer blends and biodegradable capsules, have been attempted to gain maximum control of these two factors. However, both variables have been proven to be controlled effectively through light-initiated drug delivery.

At Queen’s University, Belfast in Northern Ireland, Dr. Colin McCoy and his fellow researchers developed medications combined with photosensitive chemicals. When light falls upon the site of the body where the drugs are present, the drugs will slowly begin to release into the body. The drug release stops whenever the light is turned off or not shining directly on the site. The group’s main goal was to create a drug delivery method with minimal side effects for patients. This method also leads to more controlled drug dosage, better time release, and a cheaper drug delivery option for patients.

Although pacemakers are usually associated with the heart, Medtronic has developed a pacemaker attached to two electrodes to induce deep-brain stimulation for minimally conscious coma patients.  Figure 1 shows an x-ray image of the device in a patients head, notice how deep the device must be in order to stimulate the brain sufficiently to wake someone from a coma.  Patients with severe brain injuries often slip into comas for the rest of their lives and are more than often thought of as “gonners”.  This success story from Chicago could change the way modern medicine sees these victims.  The plan is to test the device in 12 more patients and then move on to the wide-spread clinical applications thereafter.

Figure 1

-Amy Shah