Tiny Crystals Pave The Way For Cancer Cure

Till date, the material called titanium oxide has been used to mass-produce artificial hips and knees. Now, the same material can be used in gene therapy. Researchers at the Northwestern University, USA have created extremely small crystals of titanium oxide, which ferry snippets of DNA into a cell's nucleus to repair a defective gene. This discovery may soon play a vital role in curing cancer, neurological diseases and other conditions, which occur due to defective genes. 

The crystals of titanium oxide have a diametre less than a few billionths of a metre. A nanometre scale measures such a small diametre. One nanometre equals one billionth of a metre. This is why the crystals are called nanocrystals. Existing gene therapy employs genetically modified viruses as vehicles to deliver snippets of DNA into a cell's nucleus. But a patient receiving such gene therapy may react adversely to those virus vehicles. As body does not show any adverse reactions to titanium oxide nanocrystals, it can overcome the drawback of virus aided gene therapy, said researchers Tatjana Paunesku and Grayle Woloschak of Northwestern University. 

Paunesku is a research assistant professor of radiology, and Woloschak is professor of radiology at the Feinberg School of Medicine at Northwestern University. They are also researchers at the Robert H. Lurie Comprehensive Cancer Centre of Northwestern University and at Argonne National laboratory.

 
In experiments published in a recent issue of Nature Materials, the research team showed that even in the combined form, nanocrystals of titanium oxide and the snippets of DNA retained their individual physical and biological activity. What is more, both of them possess the unique property of separating when exposed to light or x-rays. 

Armed with this insight, the researchers fitted the snippets of DNA into nanocrystals of titanium oxide and then delivered those nanocrystals into a cell's nucleus. Now, inside the nucleus, the delivered DNA binds with its 'evil twin' DNA strand, the defective gene, to form a double helix. Then the scientists exposed the nanocrystals to light or x-rays, which removed the defective gene. "We call it a 'Swiss army knife,'" said Paunesku. "Because, unlike today's drugs, we can inject 10 kinds of good genes all at once and target them in extremely specific or extremely broad ways." 

The titanium oxide nanocrystals can also deliver protein molecules to a definite target. "Right now, the research is still in the early stages of development and testing in a laboratory model is at least two years away," Woloschak said.