Nanostructured polymer brushes and protein density gradients on diamond by carbon templating

Abstract

Micro- and nanostructured polymer brushes on diamond can be directly prepared by carbon templating and amplification of the latent structures by photografting of a broad variety of vinyl monomers such as styrenes, acrylates and methacrylates. Even template structures with lateral dimensions as small as 5 nm can be selectively amplified and defined polymer brush gradients of a variety of functional polymers are realizable by this technique. Furthermore, conjugation with a model protein (GFP) results in protein density gradients of high loading and improved chemical stability. The effective functionalization of chemically and biologically inert diamond surfaces with stable functional polymer brushes, the possibility of structuring by the carbon templating technique and the direct biofunctionalization are crucial steps for the development of diamond based biosensors

Tailored Poly(2‐oxazoline) Polymer Brushes to Control Protein Adsorption and Cell Adhesion

“…Analog to our previous reports,63–65 POx‐based BBBs (POx‐BBBs) on ATMS‐SAMs were prepared by a two‐step polymerization of (a) SIPGP of IPOx to PIPOx brushes and (b) SI‐LCROP of MeOx, EtOx, and n PrOx from surface bond macroinitiator brushes. The general reaction is outlined in Scheme .…”

“…SIPGP results in a homogeneous 56 ± 3 nm thick PIPOx brush. The consecutive SI‐LCROP for 4 h at 80 °C resulted in a significant thickness increase to 140 ± 10 nm because of the stretching of the bottle‐brush backbone by the side chain crowding 63, 65. The water contact angle values slightly decreased from 49 ± 2 (PIPOx) to 44 ± 2° (PMeOx‐Pip).…”

“…This concept could be readily used to prepare grafted BBBs of different compositions and on various surfaces. Here, the BBB stem was grafted by means of self‐initiated photografting and photopolymerization (SIPGP) directly on glassy carbon63 or diamond64, 65 as both substrates are suitable for biosensing. Moreover, the BBB architecture and the POx chemistry allows for multiple functionalizations at the side chain pendant and terminal positions.…”

“…Moreover, the BBB architecture and the POx chemistry allows for multiple functionalizations at the side chain pendant and terminal positions. Hole transporting groups (carbazole)64 as well as large model proteins (e.g., GFP)65 have been introduced and demonstrating the versatility of the system for biosensing purposes. However, as glassy carbon and especially diamond shows already exceptional biocompatibility66 the protein repellant properties of the POx‐BBB coatings were not addressed.…”

Poly(2‐oxazoline)s as Polymer Therapeutics

“…[138] These results highlight the potential of POx as ideal alternatives to PEG for protein conjugation to modulate the delivery, protein activity and stability. Hutter et al [139] prepared patterned bottle-brush brushes (BBBs) of poly(2-isopropenyl-2-oxazoline-g-PEtOx) on diamond by carbon templating [140] and coupled green fluorescence protein (GFP) onto the pendant PEtOx chain ends. Besides the surprisingly high conjugation efficiency onto the BBBs, it was found that for polymer-brush-GFP conjugate the protein keeps its native state and the protein stability significantly improved as compared to the free GFP.…”