Researchers led by University of California - Los Angeles have developed a degradable nanoscale shell to carry proteins to cancer cells and stunt the growth of tumours.
The team led by Yi Tang developed tiny shells composed of a water-soluble polymer that safely deliver a protein complex to the nucleus of cancer cells to induce their death.
The shells, which at about 100 nanometres are roughly half the size of the smallest bacterium, degrade harmlessly in non-cancerous cells.
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, Tang said.
"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," Tang said in a statement.
The cell-destroying material, apoptin, is a protein complex derived from an anemia virus in birds. This protein cargo accumulates in the nucleus of cancer cells and signals to the cell to undergo programmed self-destruction.
The polymer shells are developed under mild physiological conditions so as not to alter the chemical structure of the proteins or cause them to clump, preserving their effectiveness on the cancer cells.
Tests done on human breast cancer cell lines in laboratory mice showed significant reduction in tumour growth.
"Delivering a large protein complex such as apoptin to the innermost compartment of tumour cells was a challenge, but the reversible polymer encapsulation strategy was very effective in protecting and escorting the cargo in its functional form," said Muxun Zhao, lead author of the research.
The study was published in the journal Nano Today.