Scientists have developed water-soluble polymer shells that deliver destructive material into the nucleus of cancer cells, leaving healthy cells untouched. The degradable nanoscale shells, or “nanocapsules,” are approximately half the size of the smallest bacterium.

Yi Tang, a professor of chemical and biomolecular engineering and a member of the California NanoSystems Institute at the University of California–Los Angeles (UCLA), led the group that created the nanocapsules, which are about 100 nanometers in size. As the team explained in Nanotoday as well as in a statement issued by UCLA, the nanocapsules release the protein complex apoptin to the innermost part of the tumor cell, where it accumulates. Apoptin induces apoptosis, or programmed self-destruction of the cell.

The process does not present the risk of genetic mutation posed by gene therapy, nor does it damage healthy cells as occurs in chemotherapy, according to the researchers. The shells, developed under mild physiological conditions so as not to alter the chemical structure of the proteins, degrade harmlessly in noncancerous cells.

Tang’s team reported that in tests done on human breast cancer cell lines implanted in laboratory mice, tumor growth was significantly reduced after the nanocapsules were delivered.