Tore Curstedt (Sweden)

The root cause of RDS was first documented as early as 1959 by Mary Ellen Avery and Jere Mead at the Harvard School of Public Health. The disease occurs when preterm infants lack the surfactants in their lungs that normally reduce the surface tension of the alveoli and prevent pulmonary collapse. Over the next decade, the challenge for researchers consisted of finding an alternative that mimicked the same properties of "sticking" to the surface of the lungs but enabling air to "slide off". Finally, Curstedt resorted to a naturally occurring equivalent, the poractant alfa found in the lungs of pigs.

Poractant alfa belongs to a group of chemicals known as phospholipids, fatty acids with unique characteristics in contact with water. While conventional fat cells are known for repelling water, phospholipids have a two-sided effect: one side can bind to water, for instance on the surface of cells inside the lung, while the other side - the lipid side - repels water, thereby working as a protective layer on surfaces inside the body, such as the lungs. Administered through a breathing tube inserted into the trachea, Curstedt's surfactants coat the lung membranes of preterm infants, reducing surface tension and preventing RDS.

As a young researcher at the Karolinska Institutet's laboratory, Curstedt began experimenting with surfactants to treat lung disease in the mid-1970s. In the process, he became one of the world's foremost experts in the isolation, separation and identification of phospholipids, which proved the basis for his breakthrough discovery.

During a career as a laboratory physician spanning over 40 years, Curstedt has published about 200 original articles, more than 30 review articles and several book chapters. Retired since 2013 from his position as the assistant director heading the Karolinska University Laboratory, Curstedt is currently engaged in final clinical trials for bringing to market a cost-effective synthetic surfactant, manufactured entirely without animal products. Currently known by its working name CHF5633, the drug is expected to enter the market in 2019.

For his pioneering efforts in reducing infant mortality, Curstedt has received numerous awards, including the Swedish Heart-Lung Foundation's Lars Werkö Prize (2004; jointly with Bengt Robertson) and the Chiesi Prize for Excellence in Neonatology (2011).

The discovery of surfactants is a fascinating story highlighting the interplay between medicine and physics. Through years of study, Mary Ellen Avery and Jere Mead further developed findings by physiologist John Clements to discover that the tiny and delicate alveoli sacs in the human lungs are able to retain their shape thanks to reduced surface tension. Much like soap bubbles, where the soap reduces the pressure differential between the inside and the outside of the bubble, alveoli would collapse in the absence of surfactant, with their surface tension becoming too high.

Putting the science of bubble popping into physical terms, a principle known as the Young-Laplace equation, helps explain the maximum size a bubble can be without popping. The same principle helps researchers determine the reduced surface tension necessary for properly functioning alveoli in babies (and adults).