The company has tried to create new enthusiasm with with efforts to expand into hepatitis C, the viral liver disease that is looking like the next big drug market, and into other areas such as heart disease, cystic fibrosis, and pulmonary arterial hypertension.

FORBES: Gilead Tries To Revive Itself With $11 Billion Purchase Of Pharmasset

But in conditions such as cystic fibrosis or chronic obstructive pulmonary disease (COPD), the "brush" fails to work properly, they suggest, becoming squashed and trapping mucus, which then becomes stuck to cells.

BBC: 'Brush' offers clues to fighting lung disease

Professor Danny McAuley from the Centre for Infection and Immunity, a partner in developing the new nanomedicine, said that, if successful, this nanomedicine could also have application in other common lung disorders such as Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis.

BBC: lungs