title: Protein-resistant hyperbranched polyethyleneimine brush surfaces.
abstract: A novel hyperbranched polyethyleneimine (PEI) modified gold surface has been designed, fabricated, and investigated with respect to its ability to resist non-specific adsorption of proteins. The facile synthesis strategy, based on self-assembly, involves immobilization of polyethyleneimine to gold surfaces modified with 11-mercaptoundecanoic acid (MuDA) monolayers using traditional carbodiimide chemistry. The hyperbranched polymer brushes were characterized by X-ray photoelectron spectroscopy (XPS). Reflection absorption infrared spectroscopy (RAIRS) and ellipsometry measurements showed the thickness of the PEI brushes increases with adsorption solution ionic strength. Polymer brush surface concentrations can be improved from 2560 to 3880chains/μm(2) by changing the ionic strength of the adsorption solution (PBS) by varying NaCl concentration from 0 to 650mM. Protein adsorption (pH 7.4) was evaluated under flow injection analysis (FIA) conditions using a quartz crystal microbalance (QCM). The PEI brushes suppress protein adsorption, for example, cytochrome C, bovine serum albumin (BSA), and ribonuclease A, to less than 0.08μg/cm(2) and the protein resistance increases with increasing ionic strength of the carrier solution, performance comparable to that achieved with comparable PEG-coated surfaces. The PEI brushes were exceptionally stable, with adsorption characteristics maintained after 6months storage in aqueous conditions (pH 7.4, 25°C, PBS). The potential of hyperbranched PEI structures as protein-resistant surfaces is discussed.
authors: Bioorganic & Biophysical Chemistry Laboratory, Linnæus University Centre for Biomaterials Chemistry, Linnæus University, Kalmar, Sweden.
authors: Subramanian
authors: S
authors: Suriyanarayanan
authors: Hung-Hsun
authors: HH
authors: Lee
authors: Bo
authors: B
authors: Liedberg
authors: Teodor
authors: T
authors: Aastrup
authors: Ian A
authors: IA
authors: Nicholls
mesh_terms: D000327:Adsorption; D057219:Biofouling / Q000517:prevention & control; D045304:Cytochromes c / Q000737:chemistry; D005227:Fatty Acids; D006046:Gold / Q000737:chemistry; D009994:Osmolar Concentration; D056951:Photoelectron Spectroscopy; D011094:Polyethyleneimine / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012259:Ribonuclease, Pancreatic / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013438:Sulfhydryl Compounds; D013499:Surface Properties
chemical_list: C505222:11-mercaptoundecanoic acid; D005227:Fatty Acids; D011506:Proteins; D013438:Sulfhydryl Compounds; D012710:Serum Albumin, Bovine; D006046:Gold; D011094:Polyethyleneimine; D045304:Cytochromes c; D012259:Ribonuclease, Pancreatic