Surface modification of polyurethane via creating a biocompatible superhydrophilic nanostructured layer: role of surface chemistry and structure

Abstract

Advanced surface modification approaches of biomaterials alongside the advent of sophisticated analytical techniques have provided a great opportunity to understand how the physicochemical characteristics of materials determine cellÀsurface dynamics at molecular and atomic scale. However, there are still many contradictory reports, which are mainly due to inadequate information about the role of the two parameters of surface chemistry and structure and their synergistic effect as an adequate predictor of biological performance. Here, surface parameters were altered by grafting of poly ethylene glycol (PEG) on polyurethane (PU) surfaces through a superhydrophilic modification method. In this study, surface modification of PU films by PEG thin layer via grafting technique and TiO2 nanoparticle entrapment in the brush polymers was investigated. The surface modification led to a reduction in protein adsorption and bacterial attachment by 8.7 times and 71% respectively with no cytotoxicity effect on HeLa cells. It was also observed that when PU surface became superhydrophilic the bacterial adhesion becomes independent of bacterium type. In general, it was observed that the impact of topographical changes on the biocompatibility and biofilm formation becomes significantly more profound than that of the surface chemistry alteration.

Dexamethasone Reduces the Foreign Body Reaction to Intraneural Electrode Implants in the Peripheral Nerve of the Rat

“…To improve the long‐term functional outcome of implanted electrodes, different strategies have been developed. From the biomaterials field, different polymers (Sommakia et al, ; Skousen et al, ; Lee et al, ) and surface coatings (Cui et al, ; Balaji et al, ; Noorisafa et al, ) have been investigated to reduce the FBR. In fact, these coatings have been used as local delivery systems of active molecules or drugs to modulate the inflammatory reaction in subcutaneous (Norton et al, ; Hetrick et al, ) and brain (Mercanzini et al, ; Zhong et al, ) implants.…”

Enhancing anti-thrombogenicity of biodegradable polyurethanes through drug molecule incorporation

“…Significantly lower percentage of endothelial cells adhered and proliferated on the polymeric films compared to TCPS for both the time points (p < 0.0001). This reduction in cell performance on the PU-DPA samples is due to its hydrophobic nature, which can be improved by numerous surface modification strategies including physical modification by plasma treatment, etching, gamma irradiation, X-ray treatment; 43–45 chemical modification by grafting hydrophilic materials; 46–49 and bioactive modification by immobilization of endothelial cell adhesive peptides on to polymeric surface. 50–52 However, cellular viabilities on PU-DPA (80:20) and PU-DPA (70:30) were significantly higher than that for PU-DPA (90:10) and PU-DPA (100:0) at day 3 ( p < 0.05), which was also qualitatively verified by the electron micrographs of spread HUVECs seeded on PU-DPA films (Figure 7B).…”

Rapidly prototyping biocompatible surfaces with designed wetting properties via photolithography and plasma polymerization

“…A fourth structure, a braced or strut tetrahedral concept, was designed to maintain structural stiffness and limit lithographically written material volume while simultaneously utilizing the tip-writing resolution capabilities provided by direct laser writing. Such structures with a high stiffnessto-weight ratio are also interesting in situations requiring mechanical robustness, which drastically affects wetting behavior in applications (Kondrashov and Rühe 2014;Tian et al 2016), even more so if the full volumes were written. All four different surface geometry types were printed in matrices to cover an area of 2.5 × 2.5 mm 2 .…”

“…This manuscript demonstrates the validation of this manufacturing and design strategy, with direct laser writing's adaptability and processing speed with substrate coverage areas in the square millimeter range being ideal for the requirements of such a parametric study. Plasma polymerization of HMDSO and other organosilicons in and of itself has been reported before (Wagterveld et al 2006;Tsuruta et al 2006) to achieve superhydrophobic wetting conditions, but is used in this work as a method of increasing the parametric design space while simultaneously potentially opening application areas in which biocompatibility (Noorisafa et al 2016;Bo et al 2016;Ciasca et al 2016;Falde et al 2016) and larger substrate sizes are of importance.…”