Anti-biofouling 3D porous systems: the blend effect of oxazoline-based oligomers on chitosan scaffolds

Abstract

The production, characterization and anti-biofouling activity of 3D porous scaffolds combining different blends of chitosan and oxazoline-based antimicrobial oligomers is reported. The incorporation of ammonium quaternized oligo(2-oxazoline)s into the composition of the scaffold enhances the stability of the chitosan scaffold under physiological conditions as well as its ability to repel protein adsorption. The blended scaffolds showed mean pore sizes in the range of 18-32 μm, a good pore interconnectivity and high porosity, as well as a large surface area, ultimate key features for anti-biofouling applications. Bovine serum albumin (BSA) adhesion profiles showed that the composition of the scaffolds plays a critical role in the chitosan-oligooxazoline system. Oligobisoxazoline-enriched scaffolds (20% w/w, CB8020) decreased protein adsorption (BSA) by up to 70%. Moreover, 1 mg of CB8020 was able to kill 99.9% of Escherichia coli cells upon contact, demonstrating its potential as promising material for production of tailored non-fouling 3D structures to be used in the construction of novel devices with applications in the biomedical field and water treatment processes.

Hybrid Monoliths for Magnetically‐Driven Protein Separations

“…In addition, porosity values are similar for all monoliths (82–91%). High porosity values were expected due to the freeze‐drying method employed in monoliths production, which normally generates high porosities . The specific surface area values obtained for all monoliths were within the range 0.5 and 3.0 m 2 g −1 , which is in agreement with obtained values of porosity, since the surface area varies inversely to the porosity …”

“…The addition of MNPs to the structures kept the same trend of their mechanical behavior concerning monolith's material, and hydration degree. Additionally, the obtained values are in the range of similar 3D porous structures …”

Antimicrobial activity of new green-functionalized oxazoline-based oligomers against clinical isolates

“…These two oxazoline-based oligomers were obtained by cationic ring opening polymerization (CROP) in supercritical carbon dioxide which presents several advantages comparatively to conventional synthetic routes using organic solvents (see Supplementary Information for details on the synthesis and chemical characterization of the oligomers) (Correia et al 2011 ). Among them, oligomers intrinsic blue fluorescence (Bonifácio et al 2012 ), well-defined degrees of polymerization (generally are small polymers, oligomers), low polydispersity, high purity avoiding extensive purification in the end of the procedure are very important features when envisaging biomedical applications as, for example, 3D structures modification to confer antimicrobial and self-desinfection properties (Correia et al 2013 ). This work acts as a follow-up study of Correia et al ( 2011 ), expanded the antimicrobial efficiency of the selected oligomers against clinical isolates.…”

Supercritical carbon dioxide design strategies: from drug carriers to soft killers

“…By varying the antimicrobial polymer concentration in the casting solution, the hydrophilicity, permeability, BSA adhesion profiles and bacterial killing activity of CHT-based scaffolds could be tuned. Scaffold containing 20% (w/w) of oligo(2-bisoxazoline) quaternized with N,N-dimethyldodecylamine in its composition was the three-dimensional structure with best performance in repelling protein and killing Escherichia coli upon contact (1 mg of scaffold killed 99.9% of an initial E. coli inoculum of 5 × 10 5 CFU ml −1 ) [101]. Regrettably, the physical immobilization of OOxs-DDA in the blend impaired their activity against S. aureus cells as the antimicrobial oligomer cannot diffuse through the thicker peptidoglycan layer to be effective in the inner membrane.…”