Pulmonary surfactant adsorption is increased by hyaluronan or polyethylene glycol

Kinematic viscosity of therapeutic pulmonary surfactants with added polymers

“…The reduction of surfactant viscosity caused by polymers like PEG or dextran correlates with their ability to change a diffuse three-dimensional surfactant matrix into a mostly fluid suspension (large free volume) of large aggregate clusters. This clustering occurred with the addition of PEG or dextran to the surfactants, but not with HA, in agreement with results from freeze fracture electron microscopy [18] and measurements of turbidity [17]. A similar mechanism may lie behind the low viscosities associated with the large aggregation of surfactants caused by addition of other polymers like chitosan [27].…”

“…Ten microliters of surfactant or surfactant polymer mixture, preincubated for 20 minutes at either 23 or 37°C, were sandwiched between a slide and a cover glass and examined by light microscopy. Photomicrographs were first examined to find whether flocculation was similar to previously reported results with similar polymer-surfactant mixtures studied using freeze fracture electron microscopy or spectroscopy [17, 18]. Images were then processed to improve contrast and converted into two-component (surfactant aggregates and apparent free volume) two-dimensional maps.…”

Reductions of phospholipase A2inhibition of pulmonary surfactant with hyaluronan

“…The concentrations of HA and sPLA 2 were chosen for their potential relevance when treating lung injury with HA surfactant mixtures. The concentration of HA is the lowest that improves surface activity and reduces surfactant inhibition with serum [20,23,42]. This concentration of HA is effective at 1/20 the concentration necessary to achieve the similar effect with nonionic polymers [43], and it is effective at improving lung function when added to therapeutic surfactant after experimental lung injury [20].…”

Transient Exposure of Pulmonary Surfactant to Hyaluronan Promotes Structural and Compositional Transformations into a Highly Active State

“…Moreover, the persistence length, a measure for the stiffness of a polymer chain, is particularly large for HA (19), presumably because of hydrogen bonds between adjacent saccharide units and watercaging of the glycosidic linkages (22). Together, these effects lead to an overlap concentration for HA that is about 10 times lower than that of other polymers (17,(23)(24)(25) used to enhance surfactant activity, such as PEG or dextran (3,10,11). Specific features observed in previous studies, such as the aggregation of surfactant complexes in the presence of polymers (4), led us to hypothesize that physical (i.e.…”

“…Previous work by us and others (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) has shown that a range of polymers can enhance surfactant activity, among them hyaluronan (HA). 2 HA is a naturally occurring linear polysaccharide with repeating disaccharide units of glucuronic acid and N-acetylglucosamine, linked via alternating ␤ 1-4 and ␤ 1-3 glycosidic bonds.…”