Micro Technology for Targeted Drug Delivery
02/03/16 Harsh drugs often produce powerful side effects, because the potent drug needed to the fight the illness can damage other cells in the body. For example, chemotherapy’s potent drugs used for treating cancer cells also damages other cells like hair follicles. Imagine a targeted drug delivery that only affects the intended area?
Researchers from Ohio State University and the University of Science and Technology of China teamed up to tackle this very problem. They are working on a new way to package two or more drugs into a single micro capsule. These drugs would be non-toxic when injected into the body, then a triggered mixing would produce a toxic product near the intended site in the body.
These micro-sized capsules (100 microns across) funnel different drugs through 2 inner needles. The inner needles run parallel to each other and are both enclosed in a larger outer needle, which contains an ingredient for making the outer shell of the capsule. As all the ingredients exit the needles through a single nozzle, a high-speed gas forces the liquids into a narrow stream that breaks up into individual droplets. An electric field stabilizes the flow so that uniform droplets are created. Depending on the relative flow rates, each droplet may contain two or more smaller inner droplets made from the ingredients in the inner needles.
Depending on the experimental conditions, the team was able to produce between 1,000 to 100,000 capsules per second, and nearly 100 percent of the inner liquids were incorporated into the capsules without any waste. The key features of the new device are its high efficiency and yield, and the fact that the size of the droplets can be uniformly controlled. By further fine-tuning the device’s operation, the team could make capsules that are 3-5 microns across, about the size of a red blood cell. The process can also be easily scaled up by building an array of nozzles and could be modified to encapsulate 3 or more active ingredients by adding additional inner needles.
This new micro technology might find a wider use in a range of applications that require controlled reactions.