title: Sub-micron tailoring of bi-soft segment asymmetric polyurethane membrane surfaces with enhanced hemocompatibility properties.
abstract: Enhancement of membrane hemocompatibility is achieved through the control of the surface morphology. Bi-soft segment integrally skinned poly(ester urethane urea) (PEUU) membranes containing polycaprolactone (PCL) as a second soft segment are synthesized with PCL-diol ranging from 0% to 15% (w/w). Scanning electron microscopy and atomic force microscopy characterized membrane asymmetry and sub-micron roughnesses, R(a), of top dense surfaces as major assets to the development of platelet/membrane surface interactions. Here we show that the top dense surfaces of asymmetric PEUU membranes can be tailored with different morphologies when the ratio of the two soft segments PPO/PCL varies. A strong correlation between the top surface roughnesses, R(a) and platelet deposition is identified. The membrane with 15% (w/w) of PCL-diol, PEUU 85, shows the smoothest top dense layer with a R(a) as low as 1 nm which is 5 times below the characteristic value of the PEUU membrane with a single soft segment. The PEUU 85 asymmetric membrane displayed minimal platelet deposition and inhibition of extreme stages of platelet activation.
authors.affiliation: ICEMS and Department of Chemical and Biological Engineering, Instituto Superior Tecnico, Technical University of Lisbon, 1049-001 Lisboa, Portugal.
authors.forename: Mónica
authors.initials: M
authors.lastname: Faria
authors.forename: Pedro
authors.initials: P
authors.lastname: Brogueira
authors.forename: Maria Norberta
authors.initials: MN
authors.lastname: de Pinho
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry*; D001792:Blood Platelets / Q000187:drug effects; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D015539:Platelet Activation / Q000187:drug effects; D011140:Polyurethanes / Q000009:adverse effects / Q000737:chemistry*; D011817:Rabbits; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011140:Polyurethanes