Inhibition of pulmonary surfactant adsorption by serum and the mechanisms of reversal by hydrophilic polymers: theory.
A theory based on the Smolukowski analysis of colloid stability shows that the presence of charged, surface-active serum proteins at the alveolar air-liquid interface can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the interface, consistent with the observations reported in the companion article (pages 1769-1779). Adding nonadsorbing, hydrophilic polymers to the subphase provides a depletion attraction between the surfactant aggregates and the interface, which can overcome the steric and electrostatic resistance to adsorption induced by serum. The depletion force increases with polymer concentration as well as with polymer molecular weight. Increasing the surfactant concentration has a much smaller effect than adding polymer, as is observed. Natural hydrophilic polymers, like the SP-A present in native surfactant, or hyaluronan, normally present in the alveolar fluids, can enhance adsorption in the presence of serum to eliminate inactivation.
Zasadzinski
Joseph A
JA
Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA. gorilla@engineering.ucsb.edu
Alig
T F
TF
Alonso
Coralie
C
Bernardino de la Serna
Jorge
J
Perez-Gil
Jesus
J
Taeusch
H William
HW
D000327:Adsorption; D001688:Biological Products / Q000737:chemistry; D001703:Biophysics / Q000379:methods*; D001798:Blood Proteins / Q000737:chemistry*; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D007249:Inflammation; D015233:Models, Statistical; D008962:Models, Theoretical; D008970:Molecular Weight; D009997:Osmotic Pressure; D010743:Phospholipids / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011312:Pressure; D011506:Proteins / Q000737:chemistry; D011650:Pulmonary Alveoli / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
D001688:Biological Products; D001798:Blood Proteins; D010743:Phospholipids; D011108:Polymers; D011506:Proteins; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; D006820:Hyaluronic Acid; C068291:poractant alfa; C117342:calfactant; C072197:beractant