Shanshan Guo1, Dominik Jańczewski2, Xiaoying Zhu3, Robert Quintana4, Tao He4, Koon Gee Neoh5. 1. NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Kent Ridge, Singapore 117576, Singapore. 2. Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Singapore; Laboratory of Technological Processes, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. Electronic address: dominik.janczewski@ch.pw.edu.pl. 3. Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Singapore. Electronic address: zhux@imre.a-star.edu.sg. 4. Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Singapore. 5. NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Kent Ridge, Singapore 117576, Singapore; Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Singapore. Electronic address: chenkg@nus.edu.sg.
Abstract
HYPOTHESIS: Electrostatic interactions play an important role in adhesion phenomena particularly for biomacromolecules and microorganisms. Zero charge valence of zwitterions has been claimed as the key to their antifouling properties. However, due to the differences in the relative strength of their acid and base components, zwitterionic materials may not be charge neutral in aqueous environments. Thus, their charge on surfaces should be further adjusted for a specific pH environment, e.g. physiological pH typical in biomedical applications. EXPERIMENTS: Surface zeta potential for thin polymeric films composed of polysulfobetaine methacrylate (pSBMA) brushes is controlled through copolymerizing zwitterionic SBMA and cationic methacryloyloxyethyltrimethyl ammonium chloride (METAC) via surface-initiated atom transfer polymerization. Surface properties including zeta potential, roughness, free energy and thickness are measured and the antifouling performance of these surfaces is assessed. FINDINGS: The zeta potential of pSBMA brushes is -40 mV across a broad pH range. By adding 2% METAC, the zeta potential of pSBMA can be tuned to zero at physiological pH while minimally affecting other physicochemical properties including dry brush thickness, surface free energy and surface roughness. Surfaces with zero and negative zeta potential best resist fouling by bovine serum albumin, Escherichia coli and Staphylococcus aureus. Surfaces with zero zeta potential also reduce fouling by lysozyme more effectively than surfaces with negative and positive zeta potential.
HYPOTHESIS: Electrostatic interactions play an important role in adhesion phenomena particularly for biomacromolecules and microorganisms. Zero charge valence of zwitterions has been claimed as the key to their antifouling properties. However, due to the differences in the relative strength of their acid and base components, zwitterionic materials may not be charge neutral in aqueous environments. Thus, their charge on surfaces should be further adjusted for a specific pH environment, e.g. physiological pH typical in biomedical applications. EXPERIMENTS: Surface zeta potential for thin polymeric films composed of polysulfobetaine methacrylate (pSBMA) brushes is controlled through copolymerizing zwitterionic SBMA and cationic methacryloyloxyethyltrimethyl ammonium chloride (METAC) via surface-initiated atom transfer polymerization. Surface properties including zeta potential, roughness, free energy and thickness are measured and the antifouling performance of these surfaces is assessed. FINDINGS: The zeta potential of pSBMA brushes is -40 mV across a broad pH range. By adding 2% METAC, the zeta potential of pSBMA can be tuned to zero at physiological pH while minimally affecting other physicochemical properties including dry brush thickness, surface free energy and surface roughness. Surfaces with zero and negative zeta potential best resist fouling by bovine serum albumin, Escherichia coli and Staphylococcus aureus. Surfaces with zero zeta potential also reduce fouling by lysozyme more effectively than surfaces with negative and positive zeta potential.
Authors: Shifeng Guo; Robert Quintana; Marco Cirelli; Zi Siang Desmond Toa; Vivek Arjunan Vasantha; E Stefan Kooij; Dominik Jańczewski; G Julius Vancso Journal: Langmuir Date: 2019-05-30 Impact factor: 3.882
Authors: Esther van Andel; Stefanie C Lange; Sidharam P Pujari; Edwin J Tijhaar; Maarten M J Smulders; Huub F J Savelkoul; Han Zuilhof Journal: Langmuir Date: 2018-09-28 Impact factor: 3.882