title: Elucidation of protein adsorption behavior on polymeric surfaces: toward high-density, high-payload protein templates.
abstract: The elucidation of protein adsorption behavior on polymeric surfaces is very important, since their use as arrays and carriers of biomolecules is ever growing for a wide variety of bioapplications. We evaluate protein adsorption characteristics on chemically homogeneous and heterogeneous polymeric surfaces by employing polystyrene-block-polymethylmethacrylate (PS-b-PMMA) diblock copolymer, PS homopolymer, PMMA homopolymer, and PS/PMMA blend as protein templates. We also investigate distance-dependent protein adsorption behavior on the interfacial region between PS and PMMA. We observe selective protein adsorption exclusively onto PS areas for the chemically heterogeneous PS-b-PMMA and PS/PMMA blend templates. On blend films, protein adsorption is highly favored on the PS regions located near the PS:PMMA interface over that on the PS areas situated away from the interface. Protein density on PS domains is inversely proportional to the separation distance between two neighboring PS:PMMA interfaces. We also observe a higher protein density on the PS-b-PMMA than on the PS or PMMA homopolymer templates. This effect is due to the fact that chemically heterogeneous PS-b-PMMA presents periodically spaced PS:PMMA interfaces on the nanometer scale, whereas no such interfaces are present on homopolymer films. The density of protein molecules on the heterogeneous PS-b-PMMA surface is approximately 3-4-fold higher than on the homogeneous PS surface for the identical experimental conditions. These results demonstrate that self-assembling, chemically heterogeneous, nanoscale domains in PS-b-PMMA diblock copolymers can be used as excellent, high-payload, high-density protein templates. The unique advantages of the diblock copolymer may prove the spontaneously constructed protein nanotemplates to be highly suitable as functional substrates in many proteomics applications.
authors.affiliation: Department of Chemical Engineering, The Pennsylvania State University, 160 Fenske Laboratory, University Park, Pennsylvania 16802, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Kumar
authors.forename: Omkar
authors.initials: O
authors.lastname: Parajuli
authors.forename: Abhishek
authors.initials: A
authors.lastname: Gupta
authors.forename: Jong-in
authors.initials: JI
authors.lastname: Hahm
mesh_terms: D000818:Animals; D002417:Cattle; D005353:Fibronectins / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry*; D009419:Nerve Tissue Proteins / Q000737:chemistry*; D010316:Particle Size; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005353:Fibronectins; C029152:G-substrate; D007074:Immunoglobulin G; D008689:Methacrylates; D009419:Nerve Tissue Proteins; D011137:Polystyrenes; C522509:polystyrene-block-poly(methyl methacrylate); D012710:Serum Albumin, Bovine; D019904:Polymethyl Methacrylate; D006735:Horseradish Peroxidase