Study: Once-toxic peptide may deliver large molecules

Researchers in the U.K. are taking a hard line on the delivery of biologics to treat a variety of diseases using new delivery methods to get the large molecules safely past the cell membrane.

Ishwar Singh of the University of Lincoln is developing a safe way to use cell-penetrating peptides (CPPs) to deliver biologics directly to tumors and other target sites. Although CPPs are known as a highly toxic material, the team is looking for ways to render them nontoxic but still able to selectively pass through cell membranes in cancer cells.

"Large molecule drugs are just that--too big to pass through to the diseased cells," Singh said in a statement. "The challenge is to find a way to deliver these large molecules to the cells."

Large molecules, which can include proteins, nucleic acids, sugars and other complex compounds, present a daunting challenge for delivery specialists. Finding a way to deliver the fragile material to the target without disrupting its main function is a thin line that requires, in this case, a delivery mechanism with possibly dangerous side effects.

"CPPs are known to facilitate the delivery of therapeutic biologics into target cells," he explained. "Unfortunately, current CPPs are highly toxic, which has prevented their widespread use. The aim of our project is to develop a nontoxic drug delivery method which enables CPPs to selectively pass through cell membranes of cancer cells, delivering the drug to the target site without causing toxicity."

Over time, Singh and his lab hope to use the method to treat conditions such as multiple sclerosis and cystic fibrosis, as well as some drug-resistant cancers.

- here's the University of Lincoln report