Washington: Researchers have developed daisy-shaped, nanoscale structures that are made predominantly of anti-cancer drugs and are capable of introducing a 'cocktail' of multiple drugs into cancer cells.
The researchers, who were part of the joint biomedical engineering programme at North Carolina State University and the University of North Carolina at Chapel Hill, began with a solution that contains a polymer called polyethylene glycol (PEG) to make the 'nanodaisies'.
The PEG forms long strands that have much shorter strands branching off to either side.
Researchers directly linked the anti-cancer drug camptothecin (CPT) onto the shorter strands and introduced the anti-cancer drug doxorubicin (Dox) into the solution.
PEG is hydrophilic, meaning it likes water. CPT and Dox are hydrophobic, meaning they don't like water. As a result, the CPT and Dox clustered together in the solution, wrapping the PEG around themselves.
This resulted in a daisy-shaped drug cocktail, only 50 nanometres in diameter, which can be injected into a cancer patient.
Once injected, the nanodaisies float through the bloodstream until they are absorbed by cancer cells.
One of the reasons the researchers chose to use PEG is because it has chemical properties that prolong the life of the drugs in the bloodstream.
Once in a cancer cell, the drugs are released.
"We found that this technique was much better than conventional drug-delivery techniques at inhibiting the growth of lung cancer tumours in mice," said Dr Zhen Gu, senior author of the paper and an assistant professor in the joint biomedical engineering programme.
"And based on in vitro tests in nine different cell lines, the technique is also promising for use against leukemia, breast, prostate, liver, ovarian and brain cancers," Gu said.
The study is published in the journal Biomaterials.