Shape, like size, impacts emerging nano-medicine therapies' efficacy

Washington, August 6 : Nanotechnology researchers at the University of North Carolina at Chapel Hill have discovered that tiny particles behave differently within cells depending upon their shapes, sizes, and surface chemistry.

Published in the online edition of the journal PNAS, their findings may be helpful in developing effective nanomedicines for cancer.

Dr. Joseph DeSimone, Chancellor's Eminent Professor of Chemistry in UNC's College of Arts and Sciences, has revealed that his research team used a special technique to make particles with specific shapes, sizes, and surface charges for their study.

He said that their purpose was to optimise particle attributes for specific therapeutic objectives.

"This would mean that we could deliver lower dosages of drugs to specific cells and tissues in the body and actually be more effective in treating the cancer," he said.

Having created particles of different dimensions, he added, the group changed one variable at a time, and experimented with different surface chemistries.

Dr. DeSimone says that the different particles were later incubated with human cervical carcinoma epithelial (HeLa) cells, and the group monitored each type to see which ones the cells absorbed most effectively.

He said that the long, rod-shaped particles were found to be internalised by cells about four times faster than lower aspect ratio particles.

Such particles also travelled significantly further into the cell, he added.

Stephanie Gratton, a graduate student in DeSimone's lab, said that the same phenomenon is found in natural organisms.

"If we can design particles that rely on the same mechanisms that nature has perfected for bacteria, we may unlock the key for delivering therapeutics more efficiently and effectively to treat and cure disease," she said.

Liquidia Technologies, a UNC spin-off company, is developing engineered nanoparticles for delivery of nucleic acids and small molecule therapeutics.

The company's chief executive officer, Neal Fowler, said that the new findings could prove of interest to the biopharmaceutical industry.

"We are delighted to contribute to the important work that Professor DeSimone and his students are undertaking in the field of nanomedicine. This work answers key questions about the role of particle shape and size that industry leaders have been asking for some time," Fowler said.

ANI