Imagine getting in to your car and being told to drive to a place that you never heard of, with no GPS. If you failed to reach the unknown destination, then you’ll be fired from your job and no one will ever hire you again. However, all of this could have easily been avoided if you were allowed to use a navigation system to direct you to your desired location. This situation is similar to one our society is experiencing now.
A big question that many hope to answer is, “How can we efficiently deliver a medication to a patient without it harming or interacting with other parts of the body?” and this is where research comes in. Many researchers are attempting to find ways to be able to control the release of a drug and thus lessen the side effects a person may encounter. For example, cancer patients do not suffer from hair loss, blood disorders, nausea, etc. because of the disease, but rather because of the drugs and treatment. The drugs are failing to make it to their desired destination and therefore, impact otherwise, normal parts of the body.
Fig 1. A drug is released from a polymer when the temperature is increased.
Our research lab is interested in creating, analyzing and improving potential vehicles that may be utilized to deliver bioactive compounds in an effective and detectible way. Stimuli responsive polymers are promising drug delivery systems because of the way they adapt to their environments. These smart polymers basically have a mind of their own. They can facilitate the transportation of molecules, and can also transform chemical signals into visual information. By pairing “thermos responsive” polymers with a specific dye that changes colors according to its surroundings, one may be able to track the phase changes a polymer undergoes. This may help us determine when the vehicle is going to release the drug.
For instance, the “coil-to-globular” change that a polymer undergoes determines when the drug would be released. When the polymer is swelling the drug is being loaded, and when the polymer “de-swells” or shrinks, the drug is going to be released. That is why it is important to be able to find a way to track when the polymer is going to let go of its cargo—and attack the enemy.
The polymers that our lab is working on respond to temperature changes, which means their swelling behavior will be depend on their lower critical solution temperature (LCST). When temperatures are above this value, the polymer collapses and will then be able to release the drug. By having a dye that changes colors incorporated into the polymer, it will be much easier to image and visualize the process of controlled drug delivery and find ways to improve on this method. Here’s to our hopeful GPS!
Fig 2. The coil to globular phase transition depends on LCST. Source:https://www.researchgate.net