Washington, Feb 7 (IANS): A tiny capsule designed by US researchers could suppress cancers without damaging healthy cells, shows a study.

Yi Tang, professor of chemical and bio-molecular engineering from the University of California - Los Angeles (UCLA), study co-author, reported developing tiny shells composed of a water-soluble polymer that safely deliver a protein complex to the nucleus of cancer cells to engineer their death.

The cell-destroying material, apoptin, is a protein complex derived from an anaemia virus in birds.

This protein cargo accumulates in the nucleus of cancer cells and signals to the cell to undergo programmed self-destruction.

The shells, about 100 nanometers across, are roughly half the size of the smallest bug, degrade harmlessly in non-cancerous cells, the journal Nano Today reports.

The process does not present the risk of genetic mutation posed by gene therapies for cancer, or the risk to healthy cells caused by chemotherapy, which does not effectively discriminate between healthy and cancerous cells, Yi said, according to a California statement.

"This approach is potentially a new way to treat cancer."

"It is a difficult problem to deliver the protein if we don't use this vehicle. This is a unique way to treat cancer cells and leave healthy cells untouched," Yi said.

Tests done on human breast cancer cell lines in lab mice showed significant reduction in tumour growth.