Protein‐resistant polyurethane via surface‐initiated atom transfer radical polymerization of oligo(ethylene glycol) methacrylate

Abstract

Protein-resistant polyurethane (PU) surfaces were prepared by surface-initiated simultaneous normal and reverse atom transfer radical polymerization (s-ATRP) of poly(oligo(ethylene glycol) methacrylate) (poly (OEGMA)). Oxygen plasma treatment was employed for initial activation of the PU surface. The grafted polymer chain length was adjusted by varying the molar ratio of monomer to sacrificial initiator in solution from 5:1 to 200:1. The modified PU surfaces were characterized by water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Protein adsorption experiments from tris-buffered saline (TBS) and plasma were carried out to evaluate the protein-resistance of the surfaces. Adsorption from single and binary protein solutions as well as from plasma was significantly reduced after modification. Adsorption decreased with increasing poly(OEGMA) chain length. Fibrinogen (Fg) adsorption on the 200:1 monomer/initiator surface was in the range of 3-33 ng/cm(2) representing 96-99% reduction compared with the unmodified PU. Fg adsorption from 0.01-10% plasma was as low as 1-5 ng/cm(2). Moreover, binary protein adsorption experiments using Fg and lysozyme (Lys) showed that protein size is a factor in the protein resistance of these surfaces.

Interfacial interactions of apolipoprotein AI and high density lipoprotein: Overlooked phenomena in blood‐material contact

“…Results presented here show that while albumin represents ∼50%, and apo AI ∼1%, of the total protein present in plasma, the adsorption of albumin was less than that of apo AI. Recent data reported for fibrinogen adsorption from plasma to the same PU used in this work, showed a strong Vroman effect 47. The maximum adsorption observed was 0.12 μg/cm 2 and occurred at ∼0.5% plasma for a 2 h exposure; adsorption decreased to ∼0.04 μg/cm 2 at higher plasma concentration.…”

Low‐Pressure Plasma Methods for Generating Non‐Reactive Hydrophilic and Hydrogel‐Like Bio‐Interface Coatings – A Review

“…Oehr et al also used argon plasma treatment to immobilize ethylene oxide onto siloxane plasma polymer substrates. Besides Ar plasma treatment, oxygen plasma treatment has also been used to generate peroxide radicals on polymeric substrate surfaces, which can then be used to immobilize PEG by surface‐initiated simultaneous normal and reverse atom transfer radical polymerization (s‐ATRP) of poly(oligo(ethylene glycol)methacrylate) …”

Protein‐resistant polyurethane by sequential grafting of poly(2‐hydroxyethyl methacrylate) and poly(oligo(ethylene glycol) methacrylate) via surface‐initiated ATRP

“…PU films were prepared by solution casting as described in previous work 19. PU/DMF (7% w/v) solution was added to a glass Petri dish and dried at 65°C for 5 days.…”

“…PU surfaces with sequentially grafted poly(HEMA) and poly(OEGMA) (referred to as PU/PH/PO) were prepared in five steps. Polyurethane disks were treated in an oxygen plasma produced by glow discharge (Micro‐RIE Series 800, Technics, USA) at constant power of 100 W and pressure 200 mTorr for 5 min 19, 22. The surfaces were then exposed to air for 5 min and stored in toluene for further modification with initiator. The freshly oxygen‐plasma‐treated PU disks (referred to as PU/OH) were immersed in 2‐bromoisobutyryl bromide (BIBB)/pyridine/toluene solution (volume ratio: 1.3:1:25) to form a layer of ATRP initiator, as described in previous work 19, 20.…”

“… Polyurethane disks were treated in an oxygen plasma produced by glow discharge (Micro‐RIE Series 800, Technics, USA) at constant power of 100 W and pressure 200 mTorr for 5 min 19, 22. The surfaces were then exposed to air for 5 min and stored in toluene for further modification with initiator. The freshly oxygen‐plasma‐treated PU disks (referred to as PU/OH) were immersed in 2‐bromoisobutyryl bromide (BIBB)/pyridine/toluene solution (volume ratio: 1.3:1:25) to form a layer of ATRP initiator, as described in previous work 19, 20. After 16 h reaction, the ATRP‐initiator‐immobilized PU disks (referred to as PU/initiator) were rinsed several times with ethanol for 2 h and stored in ethanol. s‐ATRP of HEMA was carried out from PU/initiator surfaces with EBIB as sacrificial initiator in solution.…”