Properties of mixed monolayers of clinical lung surfactant, serum albumin and hydrophilic polymers

It is now established that the surface activity of the clinically used lung surfactant is reduced by serum proteins and can be restored by adding the hydrophilic polymers. The mechanisms of lung surfactant inactivation by serum proteins and restoring effect by the hydrophilic polymers remain not completely understood.In this paper the state and rheological dilatational properties of surface films formed from clinical lung surfactant Exosurf, Survanta, Curosurf and Alveofact in the presence of serum albumin (BSA) and hydrophilic polymers polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and Dextran were studied. The obtained results suggest that the lung surfactant and BSA mixtures spread at air–water interface form a DPPC/BSA mixed monolayers with lower content of DPPC. The presence of hydrophilic polymers PVP, PEG and Dextran restore the DPPC content in the surface film. The effectiveness of the DPPC spreading and formation of better compacted film increases in order Exosurf, Survanta, Curosurf, Alveofact.The obtained results are in accordance with the generally admitted ideas about the mechanisms of serum protein inactivation and restoring effect of hydrophilic polymers based on the previously studies of the lung surfactant adsorption rate.

Graphical abstractMean molecular area (A¯) as a function of BSA molar ratio (XBSA), for a mixed Survanta/BSA, Alveofact/BSA, Curosurf/BSA, Survanta/BSA/PVP, Alveofact/BSA/PVP, Curosurf/BSA/PVP monolayers at surface pressure π = 15 mN m−1.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Surface films from clinical lung surfactants – LS with added BSA and hydrophilic polymers – HP are studied. ► From the state and rheological properties the effectiveness of LS film formation is estimated. ► The effectiveness of LS film formation increases in order Exosurf–Survanta–Curosurf–Alveofact. ► Surface activity of LS is reduced by BSA and can be restored by HP.