title: Chitosan enhances the in vitro surface activity of dilute lung surfactant preparations and resists albumin-induced inactivation.
abstract: Chitosan is a natural, cationic polysaccharide derived from fully or partially deacetylated chitin. Chitosan is capable of inducing large phospholipid aggregates, closely resembling the function of nonionic polymers tested previously as additives to therapeutic lung surfactants. The effects of chitosan on improving the surface activity of a dilute lung surfactant preparation, bovine lipid extract surfactant (BLES), and on resisting albumin-induced inactivation were studied using a constrained sessile drop (CSD) method. Also studied in parallel were the effects of polyethylene glycol (PEG, 10 kD) and hyaluronan (HA, 1240 kD). Both adsorption and dynamic cycling studies showed that chitosan is able to significantly enhance the surface activity of 0.5 mg/mL BLES and to resist albumin-induced inactivation at an extremely low concentration of 0.05 mg/mL, 1000 times smaller than the usual concentration of PEG and 20 times smaller than HA. Optical microscopy found that chitosan induced large surfactant aggregates even in the presence of albumin. Cytotoxicity tests confirmed that chitosan has no deleterious effect on the viability of lung epithelial cells. The experimental results suggest that chitosan may be a more effective polymeric additive to lung surfactant than the other polymers tested so far.
authors.affiliation: Department of Mechanical and Industrial Engineering, University of Toronto, Ontario, Canada.
authors.forename: Yi Y
authors.initials: YY
authors.lastname: Zuo
authors.forename: Hamdi
authors.initials: H
authors.lastname: Alolabi
authors.forename: Arash
authors.initials: A
authors.lastname: Shafiei
authors.forename: Ningxi
authors.initials: N
authors.lastname: Kang
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Policova
authors.forename: Peter N
authors.initials: PN
authors.lastname: Cox
authors.forename: Edgar
authors.initials: E
authors.lastname: Acosta
authors.forename: Michael L
authors.initials: ML
authors.lastname: Hair
authors.forename: A Wilhelm
authors.initials: AW
authors.lastname: Neumann
mesh_terms: D000418:Albumins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D000818:Animals; D002417:Cattle; D048271:Chitosan / Q000737:chemistry* / Q000633:toxicity; D004339:Drug Compounding; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D006820:Hyaluronic Acid; D008168:Lung / Q000166:cytology / Q000187:drug effects; D010743:Phospholipids / Q000737:chemistry; D011092:Polyethylene Glycols; D011663:Pulmonary Surfactants / Q000737:chemistry*; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000418:Albumins; D010743:Phospholipids; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D006820:Hyaluronic Acid; D048271:Chitosan