Chitosan as a Protective Matrix for the Squaraine Dye

Abstract

Chitosan was used as a protective matrix for the photosensitive dye-squaraine (2,4-bis[4-(dimethylamino)phenyl]cyclobutane-1,3-diol). The physicochemical properties of the obtained systems, both in solution and in a solid-state, were investigated. However, it was found that diluted chitosan solutions with a few percent additions of dye show an intense fluorescence, which is suppressed in the solid-state. This is related to the morphology of the heterogeneous modified chitosan films. The important advantage of using a biopolymer matrix is the prevention of dye degradation under the influence of high energy ultraviolet (UV) radiation while the dye presence improves the chitosan heat resistance. It is caused by mutual interactions between macromolecules and dye. Owing to the protective action of chitosan, the dye release in liquid medium is limited. Chitosan solutions with a few percent additions of squaraine can be used in biomedical imaging thanks to the ability to emit light, while chitosan films can be protective coatings resistant to high temperatures and UV radiation.

Towards a Bioactive Food Packaging: Poly(Lactic Acid) Surface Functionalized by Chitosan Coating Embedding Clove and Argan Oils

“…Amongst natural biopolymers, the amino-polysaccharide chitosan shows promising features as the incorporation matrix of bioactive additives, such as plant-derived oils or extracts [ 27 ]. Chitosan has gained attention in this field due to its many unique properties such as good film-forming ability, edibility, biodegradability, biocompatibility, nontoxicity and antimicrobial activity against fungi, Gram-positive bacteria and Gram-negative bacteria [ 20 , 28 , 29 , 30 ]. Moreover, chitosan has the ability to interact through its functional groups with different compounds in plant oils, promoting their entrapment [ 31 ].…”

Recent progress in the development of highly active dyeing photoinitiators based on 1,3-bis(p-substituted phenylamino)squaraines for radical polymerization of acrylates

“…This approach is extremely promising for the development of novel useful materials. 96 The examples presented above confirm the crucial role played by squaraine dyes in many areas of science and technology. Importantly, the application possibilities are not limited to the medical field.…”

Fluorescent Chitosan Modified with Heterocyclic Aromatic Dyes

“…Generally speaking, studies show a photoprotective effect of chitosan, which was also observed in composites of this polysaccharide with squaraine and porphyrazine-type dyes [ 47 , 48 ].…”