RMU Professor Finds Way to Send Chemotherapy Drug Directly to Tumor

Aug 8, 2012

A Robert Morris University (RMU) professor has created a computer simulation that showed incredibly small particles, or nanoparticles, could be manipulated into carrying a chemotherapy drug directly to a cancerous tumor. Since current chemotherapy drugs have more of an indirect route, the drug kills healthy cells as well as the cancerous ones, causing severe side effects, and limiting the dosage that can be given to patients.

Nanoparticles have long been known as a way to fight cancer because of their tendency to gather in high volumes near a cancerous tumor, since the area surrounding a tumor is slightly more acidic than healthy regions. As many as thirty times more nanoparticles accumulate at a cancerous site compared to normal, healthy tissue sites.

Gavin Buxton, assistant professor of physics at RMU, said the study explored whether or not a chemotherapy drug could be inserted inside a manipulated nanoparticle that gathered at a cancerous tumor, and have the drug released from there.

A computer simulation showed it's possible.

Using a simulation, Buxton theoretically put a chemotherapy drug inside an optimized nanoparticle with a hydrophilic core surrounded by a hydrophobic layer. The nanoparticle was then encapsulated by another hydrophilic, or “water-liking” layer.

“We considered the drug to be trapped inside. It couldn’t escape because of the hydrophobic [water-rejecting] layer,” Buxton said, “but then the particle itself was also biocompatible because it had this layer of hydrophilic polymer on the outside.”

Buxton said because of the nanoparticle’s mixture of water-liking and water-rejecting layers, the body in the computer simulation would not try to remove the nanoparticle, therefore making the nanoparticle capable of staying in the bloodstream longer and increasing the likelihood of the cancer drug inside the nanoparticle attacking the cancerous tumor, not healthy cells. When the nanoparticle starts to disintegrate and become more fluidic, Buxton said the hydrophobic layer surrounding the drug began to break off like a bubble bursting in the acidic tumor area.

“The more that you made it hydrophobic, the better it was at encapsulating the drug, but also the faster and larger the holes were when it started to break off,” Buxton said. “The drug kind of went through the holes and escaped from the particle.”

Buxton said their next steps include trying to interest a medical researcher as well as trying to use a hydrophilic and hydrophobic drug in the same particle. He added most chemotherapy drugs are hydrophobic, but can differ in chemical makeup.

“In terms of our research, I think one of the things we’re interested in is maybe co-encapsulating two different drugs, Buxton said. “This study that we just published was only looking at a hydrophilic drug.”