Current drug delivery methods often face a major biological roadblock: the human body itself.
A University of Arizona materials scientist has been awarded a major grant to develop a new generation of drug delivery systems that can hide from the body’s immune system by mimicking the behavior of red blood cells.
Minkyu Kim is an associate professor of materials science and biomedical engineering. The National Institute of General Medical Sciences granted the $1.9 million research award to Kim in order to develop a long-lasting drug carrier disguised as red blood cells over the next five years.
"Our immune system and filtering organs such as the liver, spleen and kidneys are very effective at removing foreign materials from the bloodstream," Kim said.
Many drug carriers are cleared from the body too quickly, and higher doses are often needed to compensate, which reduces the effectiveness of treatment, Kim said.
The funding will support his efforts to further develop synthetic drug carriers that can survive the body's natural defenses and reach hard-to-target areas, he said.
"The medicine needs to reach the right place in the body through the bloodstream... if too much medicine goes to the healthy tissues or organs, it can cause side effects,” Kim said. While drug carriers are designed to shield medicine and treatments like chemotherapy and deliver it to specific spots—such as tumors—the body’s security guards often intercept them first.
How red blood cells work
To solve this, Kim is looking to the body’s red blood cells. While many engineered particles are removed almost immediately, natural red blood cells can circulate in the bloodstream for roughly 120 days.
The key to their longevity is their cytoskeleton, a protein network that allows the cells to flex, recover and survive as they squeeze through tiny blood vessels.
Kim’s lab, the Kim Research Group, is focusing on imitating this internal protein network to create synthetic microcarriers that act like master contortionists.
“They can bend and they can squeeze through into the narrow blood vessel and they can recover their original structures, and so on, over and over again,” Kim said. If successful, the carriers could transform how harsh treatments are administered.
By staying in circulation longer, the synthetic cells could allow for lower dosage frequency and more precise delivery to hard-to-reach areas, including areas associated with heart and brain conditions.
The project will also provide hands-on research opportunities for doctoral, postdoctoral, undergraduate and high school students contributing to the investigation of these protein-based biomaterials.
"Millions of patients depend on drug delivery systems," Kim said. "If one day this research helps medicines reach the right place with fewer side effects, and patients are happier because of it, that would be the most rewarding outcome."
