Researchers load organ cells, cartilage into synthetic capsules for delivery inside the body

A team of campus researchers is developing new polymer materials that can encapsulate organ cells and other materials and deliver them inside the human body. The process is designed to replace risky organ transplants for people in need of a new liver, thyroid, pancreas, cartilage or some other crucial kind of tissue.

Surita Bhatia of the Chemical Engineering Department and her colleagues are developing several sophisticated new polymeric capsules to deliver these lifesaving organ cells. Though the research still requires more testing and refining, the theory is considered so sound that Bhatia and colleagues say they could reload their polymeric matrixes with many different kinds of tissue and expect a high probability of success.

Bhatia, who won the National Science Foundation’s 2003 Career Award based largely on her research on the polymer capsules, has been collaborating for four years with Susan Roberts of Chemical Engineering and Gregory Tew of the Polymer Science and Engineering Department. “My job is to provide the capsule material,” says Bhatia, “and make it fit each function we’re looking for.”

The concept is simple. In cell encapsulation, researchers embed a cluster of cells in complex polymeric gel. If properly engineered, the gel will not only protect the cell tissue inside, but also provide a proper environment for the cells to function chemically inside the body, including receiving all the required oxygen.

“Liver and pancreatic tissues in particular have a high demand for oxygen,” says Bhatia. “If you don’t supply enough oxygen, like the body would do with its blood supply, the organ cells might either die or not function properly.” Bhatia has been addressing the oxygenation problem by adding specific fluorocarbons to the gel that are non-toxic, FDA approved and have a high capacity for dissolved oxygen.

The cartilage-replacement research is attracting the most attention from companies looking for patents. Bhatia’s task is to customize gels that mimic the cushioning provided by diverse cartilage in the elbows, knees, ankles, shoulders and other locations. Think of trying to construct a custom-fitted football uniform with padding altered to protect various joints. “We’re trying to tailor cartilage for many different parts of the body,” says Bhatia.

Other possible applications for this cell-encapsulation technique include: time-release capsules for anti-inflammatory agents during tissue implants; disease treatment for liver disease, for instance, through implantation of encapsulated cells; and the production of pharmaceuticals and plant-derived products from plant cell cultures.