Controlled growth of protein resistant PHEMA brushes via S-RAFT polymerization

Abstract

The reversible addition-fragmentation chain transfer polymerization of 2-hydroxyethyl methacrylate (HEMA) from surfaces (S-RAFT) using an R-group-attached chain transfer agent (CTA) is presented. The approach was exploited for the efficient preparation of well-defined PHEMA brushes of up to 50 nm thickness in a controlled fashion without using any cytotoxic catalyst. The chemical composition, morphology and wettability of the samples were assessed by X-ray photoelectron spectroscopy, atomic force microscopy and water contact angle measurements, while the growth kinetics were studied by monitoring the dry thickness via spectroscopic ellipsometry. The mechanism and kinetics of the RAFT polymerization on the surfacein the presence of a sacrificial CTA and of solvent mixtures with different polaritieswere investigated. A marked effect of the concentration of the sacrificial CTA on the kinetics was observed. Importantlyand for the first timethe living PHEMA brushes were exploited as macroRAFT agents for chain extension, and thicknesses up to 70 nm were achieved. The prepared PHEMA brushes were challenged with protein solutions demonstrating their resistance to fouling.

Synthesis and Postpolymerization Modification of Thermoresponsive Coatings Based on Pentaerythritol Monomethacrylate: Surface Analysis, Wettability, and Protein Adsorption

“…7. Surprisingly, we observe high adsorption of BSA on the PPM coatings although previous reports [50][51][52][53][54] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 21 increases by more than 60% for temperature raised above the transition temperature. Enhanced temperature-sensitive BSA adsorption is most probably due to insertion of characteristic groups.…”

“…Surprisingly, adsorption of bovine serum albumin to PPM brushes, observed with fluorescence microscopy, was higher than on glass in contrast to similar hydroxyl-containing layers reported as non-fouling [50][51][52][53][54]. Moreover, influence of post-polymerization modification on protein adsorption was revealed.…”

Polymer Brushes Interfacing Blood as a Route Toward High Performance Blood Contacting Devices

“…Polymer brushes grown from the surface of the substrate have become the powerful alternative to ultra‐thin polymer coatings. With the advent of surface initiated reversible deactivation radical polymerization, such as (photoinduced) atom transfer radical polymerization (ATRP), reversible addition fragmentation transfer (RAFT) polymerization, and single electron transfer radical polymerization (SET‐LRP), it has been possible to prepare ultra‐thin coatings with an unique level of control over composition, structure, and properties. However, only few types of these brushes; based on 2‐hydroxyethethyl methacrylate, oligo(ethylenglycol) methylether methacrylate (MeOEGMA), hydroxyethyl acrylamide, oxazolines, carboxybetaines (CB), and N ‐(2‐hydroxypropyl) methacrylamide have shown a real reduction or even complete suppression of BP fouling .…”

Surface Plasmon Resonance: Advances of Label-Free Approaches in The Analysis of Biological Samples

“…Due to the pseudo-living nature of the control radical polymerizations, it is possible to prepared multiblock copolymers on which each block has a particular function, that is, resistance to fouling, immobilization of BRE, thermo/pH-responsiveness and even the possibility to exploit the end-group for further (orthogonal) reactions. Therefore, these techniques expand the synthetic platelet enabling the surface chemist to tailor the surface properties [26][27][28][29]. Various polymer brushes have been presented as antifouling because they resisted the fouling from model single protein solutions.…”