ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of hyaluronated poly(exo-7-oxabicyclo[2.2.1]hept-5-en-2,3-dicarboxylic anhydride) brushes via a combination of surface-initiated ring-opening metathesis polymerization and thiol-ene click reaction

Esra Altay Ozturk, Mehmet S. Eroglu, and Tuncer Caykara

Department of Chemistry, Faculty of Science, Gazi University, Anakara, Turkey

E-mail: mseroglu@marmara.edu.tr

Received: 7 September 2020  Accepted: 3 November 2020

Abstract:

Well-defined hyaluronated poly(exo-7-oxabicyclo[2.2.1]hept-5-en-2,3-dicarboxylic anhydride) [poly(EHDA)-HA] brushes on the hydroxyl-terminated silicon (Si–OH) surface were prepared through the combination of surface-initiated ring-opening metathesis polymerization (ROMP) and thiol-ene click reaction. This process was realized in four successive steps: (i) formation of self-assembled monolayer of (3-aminopropyl) triethoxysilane on the Si–OH surface (Si-APTES), (ii) bonding of EHDA monomer to the Si-APTES surface, (iii) synthesis of poly(EHDA) brushes via surface-initiated ROMP and (iv) coupling of thiolated hyaluronic acid (Th-HA) to poly(EHDA) chains via thiol-ene click reaction. Surface wettability, surface morphology and chemical compositions of poly(EHDA)-HA brushes were characterized by contact angle measurements, atomic force, microscopy and X-ray photoelectron spectroscopy, respectively. Grafting density (σ, chains nm⁻²) and average distance between grafting points (D, nm) of the poly(EHDA) brushes were measured to be 0.50 chains nm⁻² and 1.65 nm, independent of the [catalyst]/[monomer] ratios, which indicated that high grafting was created on the silicon substrate. However, low amounts of HA molecules were bonded to poly(EHDA) chains due to the high volume of Th-HA chains creating some steric hindrances. Biocompatible property of the poly(EHDA)-HA brushes are useful candidate for making advanced biological devices to control the behavior of biomolecules on surfaces.

Keywords: Exo-7-oxabicyclo[2.2.1]hept-5-en-2,3-dicarboxylic anhydride; Surface-initiated ring-opening metathesis polymerization (ROMP); Thiol-ene click reaction; Grafting density

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01418-5

Chemical Papers 75 (4) 1629–1638 (2021)