Conformation Variation and Tunable Protein Adsorption through Combination of Poly(acrylic acid) and Antifouling Poly(N-(2-hydroxyethyl) acrylamide) Diblock on a Particle Surface.

Zun Wang,Xuhong Guo,Kaimin Chen,Chen Hua

doi:10.3390/polym12030566

Abstract

Adsorption and desorption of proteins on biomaterial surfaces play a critical role in numerous biomedical applications. Spherical diblock polymer brushes (polystyrene with photoiniferter (PSV) as the core) with different block sequence, poly(acrylic acid)-b-poly(N-(2-hydroxyethyl) acrylamide) (PSV@PAA-b-PHEAA) and poly(N-(2-hydroxyethyl) acrylamide)-b-poly(acrylic acid) (PSV@PHEAA-b-PAA) were prepared via surface-initiated photoiniferter-mediated polymerization (SI-PIMP) and confirmed by a series of characterizations including TEM, Fourier transform infrared (FTIR) and elemental analysis. Both diblock polymer brushes show typical pH-dependent properties measured by dynamic light scattering (DLS) and Zeta potential. It is interesting to find out that conformation of PSV@PAA-b-PHEAA uniquely change with pH values, which is due to cooperation of electrostatic repulsion and steric hindrance. High-resolution turbidimetric titration was applied to explore the behavior of bovine serum albumin (BSA) binding to diblock polymer brushes, and the protein adsorption could be tuned by the existence of PHEAA as well as apparent PAA density. These studies laid a theoretical foundation for design of diblock polymer brushes and a possible application in biomedical fields.

Highlights

Interaction between protein and functional biomaterials is of great importance due to a wide range of biomedical applications such as controlled drug release [1,2], gene delivery [3], biosensors [4], medical device coating [5] and so on
Water used in this work was purified using reverse osmosis (Millipore Milli-RO, Darmstadt, Germany) and subsequent ion exchange (Millipore Milli-Q)
Brushes kinds of diblock polymer brusheswere were synthesized synthesized and characterized by TEM, Fourier transform infrared (FTIR),FTIR, Two Two kinds of diblock polymer brushes andfully fully characterized by TEM, element analysis, dynamic light scattering (DLS) and so on

Summary

Introduction

Interaction between protein and functional biomaterials is of great importance due to a wide range of biomedical applications such as controlled drug release [1,2], gene delivery [3], biosensors [4], medical device coating [5] and so on. Polymer brushes acting as typical protein carriers have been widely studied in the past few years [8]. It is well-established that polymer brushes with core-shell structures are ideal models and promising candidates due to well-defined surface polymer chains and large surface-to-volume ratios [9], as well as superior stability [10]. Diblock polymer brushes could combine two blocks with different structures and tune the comprehensive protein adsorption behavior as a whole [11,12,13,14]. Protein adsorption to polymer brushes is a highly complicated process, which is often controlled by surface properties such as hydrophilicity/hydrophobicity; surface potential; roughness and external parameters, including pH, temperature, salt concentration, etc. It is not likely that a single factor is solely responsible for the adsorption behavior but, rather, a combination of many [20]

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