Fluorinated Methacrylate-Grafted P(VDF-CTFE) and Albumin Layers for Reducing Fibrinogen Adsorption

Abstract

The use of extracorporeal devices is growing rapidly for the treatment of the fatal cardiovascular and kidney failures. Even though there has been much clinical progress in the past few decades to reduce fatality, these improvements are insufficiently supported by the development in medical devices. Particularly, it is imperative that the blood-contacting medical devices have nonprotein-fouling materials that can efficiently prevent blood coagulation. Herein, perfluoromethyl methacrylates (PFMMAs) with short perfluorinated side groups (−CF3, −CF2CF3, and −(CF2)2CF3) are strategically grafted into poly­(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) to reduce protein adhesion. On the basis of the type of the perfluorinated side group, the surface energies of the graft copolymers are controlled in the range of 11.1–18.7 mN m–1. The graft copolymer with the lowest surface energy showed the lowest protein adsorption for both albumin and fibrinogen, as compared with the other graft copolymers and PMMA. Interestingly, albumin pretreatment of the surface remarkably reduces the amount of adsorbed fibrinogen from 2069 ng cm–2 (without albumin pretreatment) to 5.6 ng cm–2. This indicates that the graft copolymer is practically useful for various blood-contacting devices because fibrinogen is the key glycoprotein that induces blood coagulation.

Access to Fluorinated Polymer Surfaces with Outstanding Mechanical Property, High Optical Transparency, and Low Surface Energy via Nonafluoro-tert-Butyl Group Introduction

“…The experimental F/C ratios of NFtB-19.7, −38.1, −57.4, and −77.3 were similar to or lower than the corresponding theoretical values, which indicated similar surface occupancies of carbon and fluorine atoms or rather the formation of carbon-enriched surfaces. It has been reported that functional groups with lower surface energies prefer to be located at the surface–air interface rather than inside the polymer film. ,,, Particularly, linear fluorocarbon chains have a strong tendency to migrate toward the surface due to their extremely lower surface energies . The F/C ratios of the films of P­(MMA–HFBMA) copolymers with linear fluorocarbon tails (−CF 2 CF 2 CF 3 ) in the HFBMA unit were indicative of fluorine-enriched compositions over the whole range of copolymer ratios (Figure S5).…”

“…It has been reported that functional groups with lower surface energies prefer to be located at the surface−air interface rather than inside the polymer film. 7,20,49,50 Particularly, linear fluorocarbon chains have a strong tendency to migrate toward the surface due to their extremely lower surface energies. 51 The F/C ratios of the films of P(MMA−HFBMA) copolymers with linear fluorocarbon tails (−CF 2 CF 2 CF 3 ) in the HFBMA unit were indicative of fluorine-enriched compositions over the whole range of copolymer ratios (Figure S5).…”

“…Fluorinated compounds have received much attention because of their thermal and chemical inertness, low refractive index, and water and oil repellency, finding applications in the fields of water treatment, self-cleaning coatings, , fuel cell membranes, and biomedical devices . These advantageous properties originate from the low polarizability of fluorine atoms and the high strength of C–F bonds, which can substitute C–H bonds with only small conformational changes. , Consequently, the use of fluoro-functionalization (or fluorination) to enhance material properties has attracted much interest, especially in the field of industrial polymer production.…”