Nanoshells could enhance precision of cancer treatment

Researchers at UCLA have developed a degradable nanoscale shell to carry proteins to cancer cells and inhibit the growth of tumours without damaging healthy cells.

Developed at the UCLA Henry Samueli School of Engineering and Applied Science, the new nanoshells are expected to deliver a more precise and less invasive treatment of cancer tumours.

In a new study, published in Nano Today, a group led by Yi Tang, a professor of chemical and biomolecular engineering and a member of the California NanoSystems Institute at UCLA, reported developing tiny shells composed of a water-soluble polymer that deliver a protein complex to the nucleus of cancer cells. The shells themselves 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 in a statement.

‘This approach is potentially a new way to treat cancer,’ said Tang. ‘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.’

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 together, preserving their effectiveness on the cancer cells.

Tests done on human breast cancer cell lines in laboratory mice are said to have shown 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 and a graduate student in chemical and biomolecular engineering at UCLA.