Structure of Water Incorporated in Sulfobetaine Polymer Films as Studied by ATR‐FTIR

Abstract

The structure and hydrogen bonding of water in the vicinity of a thin film of a sulfobetaine copolymer (poly[(N,N-dimethyl-N-(3-sulfopropyl)-3'-methacrylamidopropanaminium inner salt)-ran-(butyl methacrylate)], poly(SPB-r-BMA)), were analyzed with band shapes of O-H stretching of attenuated total reflection infrared (ATR-IR) spectra. The copolymer could be cast as a thin film, of approximate thickness 10 microm, on a ZnSe crystal for the ATR-IR spectroscopy. At an early stage of sorption of water into the polymer film, the O-H stretching band of the IR spectra for the water incorporated in the film was similar to that for free water. This is consistent with the tendency for another zwitterionic polymeric material, poly[(2-methacryloyloxyethylphosphorylcholine)-ran-(butyl methacrylate)] (poly(MPC-r-BMA). It is, however, contradictory to the drastic change in the O-H stretching band for water incorporated into films of polymers such as poly(2-hydroxyethyl methacrylate), poly(methyl methacrylate) and poly(butyl methacrylate). These results suggest that polymers with a zwitterionic structure do not significantly disturb the hydrogen bonding between water molecules incorporated in the thin films. The investigation into the blood-compatibility of both the poly(SPB-r-BMA) and the poly(MPC-r-BMA) films indicate a definite correlation between the blood-compatibility of the polymers and the lack of effect of the polymeric materials on the structure of the incorporated water.

Ultralow‐Fouling, Functionalizable, and Hydrolyzable Zwitterionic Materials and Their Derivatives for Biological Applications

“…[32,43,58,59] The ''graft-to'' method involves (i) the preparation of polymers containing nonfouling and adhesive groups, such as 3,4-dihydroxyphenylalanine (DOPA) groups [24,60] and polylysine segments, [61] and (ii) the direct attachment of the polymers onto the surface. pSB and pCB have been grafted to or from surfaces via several common adhesive linkers, including thiols for a gold surface, [43,45,47,50,51,62,63] silanes for a glass surface, [64] hydrophobic moieties for a hydrophobic surface, [41,65,66] or DOPA for various surfaces, [67,68] or via interpenetrating networks (IPNs) into polyurethane (SPU) matrices. [69] pSB-based hydrogels have also been prepared.…”

Anti‐Biofouling Properties of Polymers with a Carboxybetaine Moiety

“…[49] As mentioned in the Introduction, we have also found by FT-IR and Raman spectroscopies that the hydrogen-bonded network structure of water in the vicinity of zwitterionic polymers was not greatly different from that of pure water. [23][24][25][26][27] Small perturbation of the structure of water primarily hydrating zwitterionic polymer materials has also been reported, [50] and this indicates that the hydration layer at the surface of a zwitterionic polymer might not be so thick. Therefore, we speculate that the hydration layer around a protein molecule that is approaching the surface of zwitterionic polymer collides with the relatively thin hydration layer on the polymer.…”

“…[21,22] The solution behavior of zwitterionic polymers is often opposite to that of typical polyelectrolytes, exhibiting ''anti-polyelectrolyte'' behavior. Using Raman and IR spectroscopies, we have found that the hydrogen-bonded network structure of water in the vicinity of zwitterionic polymers (phosphobetaine, sulfobetaine and carboxybetaine polymers) was not greatly disturbed, [23][24][25][26][27] suggesting that the small perturbation effect of zwitterionic polymers on the structure of water at polymer-water interfaces is crucial for the biocompatibility of the polymers.…”

Effect of Zwitterionic Polymers on Wound Healing

“…15) Platelet adhesion and complement activation on the polymer surface of poly(CMB-r-BMA) showed a minimum value around 30% of the mole ratio of CMB. Polymers containing zwitterionic moieties such as 2-methacryloyloxyethylphosphorylcholine (MPC) 16) and 3-sulfo-N,N-dimethyl-N-3Ј-methacrylamidopropylpropanaminium inner salt (SPB) 17) also have excellent blood compatibility.…”