Antimicrobial Cost-Effective Transparent Hydrogel Films from Renewable Gum Karaya/Chitosan Polysaccharides for Modern Wound Dressings

Abstract

The newest trends in wound healing management and the development of the next generation of dressings are pointing toward natural polymeric materials with important beneficial properties such as antimicrobial effects, renewability, easier process of preparation, and biological activity. Here, we present the preparation and in vitro evaluation of a unique biopolymeric blend composed of natural polymers based on the positively charged polysaccharide chitosan and negatively charged gum karaya. A plate lysis assay of gum karaya and chitosan solution mixtures proved the synergistic antimicrobial effect against specific strains of both Gram-positive and Gram-negative bacteria and yeast. This polymeric mixture was used for hydrogel film preparation and determination of the composition effect on physical properties (swelling behavior in different solvents, pH, diffusion mechanism, hydrolytic stability, mechanical and optical properties). While the pure gum karaya with poly(vinyl alcohol) exhibited the highest hydrolytic degradation (68%), the mixture of poly(vinyl alcohol) and gum karaya with chitosan (in the 25:75 ratio) exhibited the lowest degradation value (41%) due to the strong physical interactions. Cytotoxicity tests performed with hydrogel extracts using two different in vitro models, adherent fibroblasts (NIH3T3) and non-adherent suspension B-lymphocytes (BaF3), exhibited excellent biocompatibility and no cytotoxicity. As expected, the antimicrobial activity of 3-day film extracts showed a significantly improved antimicrobial effect of mixtures involving a chitosan biopolymer. The physical and biological properties of prepared biopolymer-based hydrogels meet the requirements of modern wound dressings.

Karaya/Gellan-Gum-Based Bilayer Films Containing 3,3′-Diindolylmethane-Loaded Nanocapsules: A Promising Alternative to Melanoma Topical Treatment

“…When comparing the different films in the transmittance spectrum, a reduction was noted in the vehicle film after the incorporation of free DIM or nanocapsules. Similar results were obtained by other studies that developed films containing nanosystems, and this effect was attributed to the ability of colloidal systems to scatter light [ 24 , 46 , 69 ]. Regarding the film containing the free bioactive, the reduction in transmittance may be suggestive of crystals of the bioactive, considering its lipophilicity and insertion in a hydrophilic matrix [ 10 ].…”

“…Another polysaccharide that stands out is karaya gum, obtained from exudative lesions on the stem of Sterculia urens , a tree typical of India and Africa [ 42 , 43 ]. Although this gum has essential properties such as bioadhesion behavior and control of the release of substances, few studies have been dedicated to preparing films of karaya gum for pharmaceutical purposes [ 44 , 45 , 46 , 47 ]. Furthermore, using karaya gum in developing these films was associated with other polymeric materials, in its deacetylated or cross-linked form, with no incorporation of nanostructured systems.…”

Gums as Macromolecular Crowding Agents in Human Skin Fibroblast Cultures

“…Gum gellan (GG) has been used as a scaffold for skin [46], intervertebral disc [47], and dental [48] applications. Gum karaya (GK) has also been used as part of drug delivery vehicles [49,50]. Gum xanthan (GX) has been used extensively in the development of skin substitutes [51,52].…”