Tunable Bioadhesive Copolymer Hydrogels of Thermoresponsive Poly(N-isopropyl acrylamide) Containing Zwitterionic Polysulfobetaine

Abstract

This work describes a novel tunable bioadhesive hydrogel of thermoresponsive N-isopropylacrylamide (NIPAAm) containing zwitterionic sulfobetaine methacrylate (SBMA). This novel hydrogel highly regulates general bioadhesive foulants through the adsorption of plasma proteins, the adhesion of human platelets and cells, and the attachment of bacteria. In this investigation, nonionic hydrogels of polyNIPAAm, zwitterionic hydrogels of polySBMA, and three copolymeric hydrogels of NIPAAm and SBMA (poly(NIPAAm-co-SBMA)) were prepared. The copolymeric hydrogels exhibited controllable temperature-dependent swelling behaviors and showed stimuli-responsive phase characteristics in the presence of salts. The interactions of these hydrogels with biomolecules and microorganisms were demonstrated by protein adsorption, cell adhesion, and bacterial attachment, which allowed us to evaluate their bioadhesive properties. An enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies was used to measure different plasma protein adsorptions on the prepared hydrogel surfaces. At a physiological temperature, the high content of the nonionic polyNIPAAm in poly(NIPAAm-co-SBMA) hydrogel exhibits a high protein adsorption due to the interfacial exposure of polyNIPAAm-rich hydrophobic domains. A relatively high content of polySBMA in poly(NIPAAm-co-SBMA) hydrogel exhibits reduced amounts of protein adsorption due to the interfacial hydration of polySBMA-rich hydrophilic segments. The attachment of platelets and the spreading of cells were only observed on polyNIPAAm-rich hydrogel surfaces. Interestingly, the incorporation of zwitterionic SBMA units into the polyNIPAAm gels was found to accelerate the hydration of the cell-cultured surfaces and resulted in more rapid cell detachment. Such copolymer gel surface was shown to be potentially useful for triggered cell detachment. In addition, the interactions of hydrogels with bacteria were also evaluated. The polySBMA-rich hydrogels exhibited evident antimicrobial properties when they were incubated with Gram-positive bacteria ( S. epidermidis ) and Gram-negative bacteria ( E. coli ). This work shows that the bioadhesive properties of poly(NIPAAm-co-SBMA) hydrogels can be effectively controlled via regulated nonionic and zwitterionic molar mass ratios. The tunable-bioadhesive behavior of temperature-sensitive poly(NIPAAm-co-SBMA) makes this biocompatible hydrogel appropriate for biomedical applications.

Charged hydrophilic polymer brushes and their relevance for understanding marine biofouling

“…In contrast, the air bubble contact angle in ASW increased on PSBMA, compared to the contact angle in deionized water. This increase might be a result of the unique antipolyelectrolyte behavior of PSBMA, i.e., chain expansion due to a viscosity increase in the presence of salt ions, as has been reported previously (Chang et al 2009, Chang et al 2010. It is useful to compare the contact angles obtained with sessile droplets in air with those obtained underwater on the hydrated films.…”

Hydrogel-coated feed spacers in two-phase flow cleaning in spiral wound membrane elements: A novel platform for eco-friendly biofouling mitigation

“…Hydrogel-based materials have been reported to have good anti-biofouling properties and have great potential to be applied as antifouling coatings (Chang et al 2010).…”

Thermo-Responsive Hydrogels for Stimuli-Responsive Membranes

“…Polysulfobetaines have also gained much interest as a biocompatible material with high protein fouling resistance [50]. Copolymerizations with other biocompatible thermo-responsive polymers have formed temperature triggered cell-detachment surfaces [57].…”