Properties of phospholipid monolayer deposited on a fluorinated polyurethane

A simple procedure for surface modification of polyurethane by the Langmuir-Blodgett (LB) method using the amphiphile 1,2-distearoyl-sn-glycero-3-phosphocholine dihydrate (DSPC) was developed. The polyurethane containing the fluorinated moiety was prepared via the perfluoro-containing chain extender 2,2,3,3-tetrafluoro-1,4-butanediol. The fluorinated polyurethane (FPU) films were prepared by spin coating and dipping methods. The spin-coated FPU films exhibited hydrophobic characteristic and, thus, enhanced the transferability of DSPC. Held at constant pressure of 45 mN/m, the DSPC monolayer was transferred successfully to FPU films with a near-unity transfer ratio. The in vitro platelet adhesion assay revealed that the FPU modified with DSPC monolayer was more platelet compatible than the unmodified FPU substrates with no pseudopods and flattening of adherent platelets as well as lower platelet adhesion density. Moreover, the DSPC monolayer remained intact after platelet adhesion testing. In addition, the platelet compatibility of the unmodified FPU was affected by the film preparation methods. This might be attributed to the distinctive surface micromorphology formed. This simple DSPC deposition scheme by a LB technique would be very useful to further enhance the platelet compatibility of hydrophobic substrate and can be utilized for biomedical application in which the flow shear rate is not too high.