Bubbles contain lung-cancer drugs

Lung-cancer patients could be treated by inhaling tiny drug-containing bubbles with a new technique being developed by two competing scientific teams from the US and UK.

The inhalation treatment would replace intravenous injections of Cisplatin, a lung-cancer treatment drug usually administered in high doses.

The toxic drug poisons cells and causes side effects that severely debilitate patients as it travels around the blood stream.

Transave, a US biopharmaceutical company, and researchers at Strathclyde University have separately developed a method for delivering Cisplatin directly to the lungs using inhaled bubbles.

While the concept behind their techniques is relatively the same, the materials used to make the bubbles differ. The Transave bubble is based on a lipid and the Strathclyde University team has developed a bubble made of a surfactant, cholesterol and dicetylphosphate.

Katharine Carter, a member of the Strathclyde University research team, said the reagents that make up their bubble are more robust, and the manufacturing method has the potential to be much simpler.

Neither technique is commercially available; however, Transave has already taken its drug-delivery system to stage two clinical trials, while Strathclyde is still performing animal testing.

Carter said her team is not worried about its system being beaten to market. ‘It’s better to go in second because you can see things that you can maybe do better,’ she added.

The technique would work by placing drug-containing bubbles in the solution container of a nebuliser. Carter said their animal trials indicate a patient would only have to breathe in the bubbles for 6.5 minutes.

When the bubbles reach the lung, she added, they will be met by a vast amount of macrophages, which are white blood cells that break down pathogens with special enzymes.

Carter explained that these macrophages would recognise the bubbles as a pathogen and bust them open. ‘The drug will then be released locally at the cells and into the environment nearby,’ she said.

The Strathclyde University researchers are currently funded by Scottish Enterprise, but Carter said the team hopes to attain additional funding to start a spin-out company.

The team hopes to achieve this soon, she added, and begin clinical trials in the next six to eight months. Following that, the Strathclyde researchers plan to develop their product further and - depending on cash flow - sell the formulation themselves or to a large pharmaceutical company.

Carter said the team is hopeful its product will be commercially available in two years.

Siobhan Wagner