Protein Adsorption on Poly(N-vinylpyrrolidone)-Modified Silicon Surfaces Prepared by Surface-Initiated Atom Transfer Radical Polymerization

Abstract

Well-controlled poly(N-vinylpyrrolidone) (PVP)-grafted silicon surfaces were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) with 1,4-dioxane/water mixtures as solvents and CuCl/5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (Me6TATD) as a catalyst. The thickness of the PVP layer on the surface increased with reaction time, suggesting that the ATRP grafting of N-vinylpyrrolidone (NVP) from the silicon surfaces was a well-controlled process. The water contact angle and X-ray photoelectron spectroscopy (XPS) were used to characterize the modified surfaces. The protein adsorption property of the PVP-grafted surfaces was evaluated using a radiolabeling method. Compared with unmodified silicon surfaces, a Si-PVP60 surface with a PVP thickness of 15.06 nm reduced the level of adsorption of fibrinogen, human serum albumin (HSA), and lysozyme by 75, 93, and 81%, respectively. Moreover, the level of fibrinogen adsorption decreases gradually with an increase in PVP thickness. However, no significant difference in fibrinogen adsorption was found when the PVP layer was thicker than the critical thickness of 13.45 nm.

Surface Modification to Control Protein/Surface Interactions

“…Very recently, we prepared wellcontrolled poly(N-vinylpyrrolidone) (PVP)-grafted silicon surfaces for the first time using SI-ATRP. [26] It was found that surfaces with thick grafted layers showed a dramatic reduction in the level of adsorption of three model proteins (fibrinogen, human serum albumin, and lysozyme) with varying properties. As the thickness of the PVP layer increased, the water contact angle (WCA) gradually decreased and then remained constant beyond a ''critical'' thickness of $13 nm.…”

Efficient delivery of ursolic acid by poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) nanoparticles for inhibiting the growth of hepatocellular carcinoma in vitro and in vivo

“…11 Recently, it was reported that the capability of PVP to prevent protein adsorption was correlated with its coating and molecule weight. 13,14 It was found that the nanoparticles coated by PVP, with molecular weight of 2,500 and 4,800 Da, were rapidly removed from blood due to complement components and immunoglobulins adsorption. 14 In this report, we loaded UA into poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) (PVP-b-PCL) nanoparticles and performed physiochemical characterization.…”

Droplet microfluidics: A tool for biology, chemistry and nanotechnology

“…Examples include modification by silane (e.g. PEG-silane or silane with fluorinated groups) and polyelectrolyte multilayers (PEMs) that can be used to modulate hydrophobicity, charge and to add biological specificity to surfaces [19]. For multiphase droplet generation, channel surface properties differ at different stages of droplet synthesis, depending on the continuous phase at different positions in the chip, while for singlephase droplet systems typically the continuous phase does not change and a uniform surface chemistry is used along the channel [20,21].…”