Researchers study cell binding methods

Three IU researchers from the Department of Chemistry studied how cell membrane-coated nanoparticles, or particles the size of a nanometer, bind to target cells in 2016. Their work was published last month in American Chemical Society's journal ACS Nano.

For size comparison, the diameter of a human hair is 2.5 nanometers. 

The team hopes that the knowledge they gained and the help of inquiries by future scientists can make vaccines and drug delivery more effective.

The research team is studying the process strictly for knowledge. For example, it's like if a new chemical was discovered. The researchers' first goal is to learn all they can about the chemical, and then think about the real-world applications. The same method is being used here. 

Corresponding author Yan Yu said the research had a simple goal: to start examining the bonding process of a nanoparticle unit and an artificial cell membrane.

The research used two different nanoparticles as a unit and then color-coded both as a way of keeping the particles identifiable, graduate student Yanqi Yu said.

“We wanted those particles to be in color, so we can track them,” Yanqi Yu said.

Yan Yu said she characterized her team’s approach as having a magnifying glass amplifying the different movements and interactions of the nanoparticle binding process.

“Normally, you would just see this one phenomenon, but actually if you zoom in, you would see there are many different subsets of stages in this normal particle binding process,” Yan Yu said.

The theory behind the movement of nanoparticles when bonded to a target cell is that the particle is effectively stuck during the process, Yanqi Yu said. However, the research team found a different occurrence. 

Yan Yu said when the nanoparticle movements rock back and forth, the particle is in the first stage and attempting to bond to the artificial cell membrane. The rocking movement is used to attract more molecules and strengthen the bond.

When the bond is at the required level, the nanoparticle takes on a more circling movement is next, Yan Yu said.

One of the more trendy types is particles coated with cell membranes taken from real cells so it is harder for the immune system to differentiate between foreign organisms and self.

“One of the emerging types of drug delivery particles is actually particles that have been coated with cell membranes from real cells,” Yan Yu said.

Yanqi Yu said it is important that as few particles are attacked by the body’s immune system as possible because the fewer particles transporting the drug, the lesser effect it will have overall.

“If you camouflage the particular particle with a cell membrane from the patient’s old body, the patient won’t recognize the particle as a pathogen,” Yanqi Yu said.

The research being conducted is about gaining more knowledge about nanoparticle binding, Yan Yu said. However, later on, the findings may improve drug delivery methods and the efficiency of vaccines.