Self‐assembly of Protein Nanoarrays on Block Copolymer Templates

Abstract

There is considerable interest in developing functional protein arrays on the nanoscale for high‐throughput protein‐based array technology, and for the study of biomolecular and cell interactions at the physical scale of the biomolecules. To these ends, self‐assembly based techniques may be desirable for the nanopatterning of proteins on large sample areas without the use of lithography equipment. We present a fast, general approach for patterning proteins (and potentially other biomolecules) on the nanoscale, which takes advantage of the ability of block copolymers to self‐assemble into ordered surface nanopatterns with defined chemical heterogeneity. We demonstrate nanoarrays of immunoglobulin and bovine serum albumin on polystyrene‐block‐poly(methyl methacrylate) templates, and illustrate the applicability of our technique through immunoassays and DNA sensing performed on the protein nanoarrays. Furthermore, we show that the pattern formation mechanism is a nanoscale effect originating from a combination of fluid flow forces and geometric restrictions templated by an underlying nanopattern with a difference in protein adsorption behavior on adjacent, chemically distinct surfaces. This understanding may provide a framework for extending the patterning approach to other proteins and material systems.

Controlling Protein Adsorption through Nanostructured Polymeric Surfaces

“…As presented in numerous studies, various proteins exhibit biased adsorption to one of the polymeric nanodomains (Figure 7a). [124][125][126][127] For instance, fibrinogen, horseradish peroxidase, or albumin, was found to selectively adsorb onto the PS nanodomains of the diblock copolymer surfaces (Figure 7b). [41] Furthermore, as shown in Figure 7c, protein adsorption is highly favored on the PS region close to the chemical interface defined by the two neighboring PS and PMMA nanodomains.…”

Modulation of Protein−Surface Interactions on Nanopatterned Polymer Films

“…[11][12][13][14][15][16][17] Previous reports have also explored the effect of a nanopattern on adsorption behavior. For example, the presence of chemical nanostripes with line widths close to that of individual proteins has been shown to induce proteins to preferentially adsorb with an orientation aligned with the nanopattern's anisotropy.…”

“…PS and PMMA have almost identical surface energies in air, [25][26][27] thus skin layer formation was minimized during PS-b-PMMA block copolymer self-assembly, and topographically flat polymer nanopatterned surfaces could be prepared. 17,24,25 The use of an in situ technique for quantifying protein adsorption ensured that the measurements reflected the native configurations of the proteins adsorbed on the nanopatterned surfaces. Moreover, unlike previous studies that employed an extreme contrast in hydrophobicity to generate a biomolecular response, such as with alkyl/poly(ethylene-oxide) 3,18 or oxide/metal 20 nanopatterns, the PS and PMMA used in this report are both poorly solvated in water and are comparatively similar in hydrophobicity.…”

Poly(vinylpyrrolidone-b-styrene) block copolymers tethered surfaces for protein adsorption and cell adhesion regulation

“…Fabricating polymer brushes on a solid substrate is wellknown, and it has been successfully used as an effective way to control surface properties [9]. Taking advantage of the fact that the block copolymer can form regular nanoscale patterns over a macroscopic area via a self-assembly process, spun-cast copolymer films have been utilized in protein patterning and protein adsorption regulating [10][11][12]. Very recently, George et al [8] reported a method for biomaterial surface modification that utilizes the self-assembly of block copolymers of poly(styrene-block-ethylene oxide) (PS-PEO) to generate microphase separated surfaces.…”