A team of MIT engineers has equipped cells with tiny "backpacks" that could allow them to release chemotherapeutic agents, diagnose tumors, or become building blocks for tissue engineering.
Michael Rubner, director of MIT's Center for Materials Science and Engineering and lead author of an article about the work published online in the journal Nano Letters on November 5, believes this is the the first time anyone has succeeded in attaching such a synthetic patch to a cell.
Polymeric backpacks allow researchers to use cells to carry tiny charges and manipulate their movements using magnetic fields. Since each patch covers only a small part of the cell's surface, it does not interfere with the cell's normal functions or prevent it from interacting with the external environment.
"The goal is to disturb the cell as little as possible," said Robert Cohen, a professor of chemical engineering at MIT and one of the authors of the work.
The researchers worked with B and T cells, two types of immune cells that can locate and target various tissues in the body, including tumors, sites of infection, and lymphoid tissues; a trait that could be exploited for targeted drug or vaccine delivery.
Cell backpacks, loaded with chemotherapeutic agents, could target tumor cells, while cells equipped with a load of contrast agents could help identify tumors by binding to protein markers expressed by cancer cells.
It can also be applied in tissue engineering. These patches could be designed to allow researchers to line up cells in a certain pattern, eliminating the need for a tissue structure.
The polymeric patch system consists of three layers, each with a different function, stacked on one surface. The lower layer holds the polymer to the surface, the middle layer contains the charge, and the upper layer acts as a “hook” to catch and bind to the cells. Once the layers are in place, the cells are introduced into the system so that they flow over the surface and remain hooked on the polymeric hooks; then the patch is released from the surface, decreasing the temperature, and the cells float away with the backpacks attached to them.
By loading the backpacks with magnetic nanoparticles, the researchers can control cell movements using a magnetic field.