Bioactive transparent films based on polysaccharides and cholinium carboxylate ionic liquids

Abstract

Novel antibacterial and biocompatible transparent films based on chitosan or pullulan and two bioactive ionic liquids (ILs), cholinium hexanoate and cholinium citrate, were prepared. These ILs were selected based on their MIC values against several microbial strains, film-forming ability when blended with the polysaccharides and biocompatibility against designated human cell lines. The films were obtained through simple casting of polysaccharide aqueous solutions containing different amounts of the ILs (20 and 40 wt% with respect to the amount of polysaccharide). The physical properties of the films were investigated using transmittance measurements, thermal analysis, mechanical testing and antibacterial assays. In general, the addition of both ILs does not affect the optical transparency (up to 80% transmittance within 400-700 nm) of the films but decreased their stiffness (acting as plasticizers) and thermal stability. All chitosan-based films showed antibacterial activity against S. aureus and K. pneumoniae but for pullulan only those with cholinium citrate were bioactive.

Anti-inflammatory and antioxidant nanostructured cellulose membranes loaded with phenolic-based ionic liquids for cutaneous application

“…Pure BC membranes and BC-ILs do not cause any decrease in cell viability (above >90%) for both cell lines. These observations are in line with existent reports in literature showing good biocompatibility profiles for either BC (Helenius et al, 2006; Jeong et al, 2010) and cholinium-based ILs (Sintra et al, 2015; Tomé et al, 2015). …”

“…BC presents also the highest tensile stress (3.76 ± 9.3 GPa) followed by BC-[Chol][Caf] and BC-[Chol] 2 [Ell], which presents tensile stress values approximately 30% lower than BC. BC-[Chol][Gal] presents the lowest tensile stress, (0.94 ± 0.35 GPa), and taking into account its lower elongation at break, can be considered the most fragile membrane (Tomé et al, 2015). Although some modifications to the main mechanical characteristics of BC were provoked by the incorporation of ILs, they do not compromise the application in skin care treatments.…”

Ionic Liquid Stabilized Gelatin–Lignin Films: A Potential UV‐Shielding Material with Excellent Mechanical and Antimicrobial Properties

“…Choline citrate was synthesized by following the procedure published elsewhere. [14] In brief, choline bicarbonate and equimolar citric acid were mixed while maintaining the reaction temperature at < 5 8C. The reaction was carried out for 24 hw ith continuous stirring at room temperature.…”

“…[13] The use of ILs derived from biological molecules for biomass processing have been shown to provide additional advantages in terms of development of sustainable bioactive biomaterials. [14] Recently,w ec onstructedaUV-resistant film from the IL-processed residual biomass of cinnamomum cassia bark and chitosan. [15] The films showede xcellent UV-light resistance andm echanical properties but lacked transparency and bioactivity.…”

An Overview on Antioxidants Activity of Polysaccharide Edible Films and Coatings Contains Essential Oils and Herb Extracts in Meat and Meat Products

“…Application of antioxidants in biodegradable edible films and coatings improved properties and preservation of food . Among various edible films/ coatings, polysaccharide biopolymers were used in a wide range in foods because of their desirable properties, margin of safety, and structure diversity (Tomé et al, 2015). This overview discusses the rationale of using edible film/ coatings for polysaccharides contains essential oils and plant extracts in food products.…”