Chitin

About: Chitin is a research topic. Over the lifetime, 6590 publications have been published within this topic receiving 253993 citations.

Novel fibers fabricated directly from chitin solution and their application as wound dressing

Abstract: For the first time, pure chitin fibers with relatively high strength, lustrous surface and circular cross section were spun directly from chitin solution dissolved in an NaOH–urea aqueous system with freezing. Subsequently, chitin nonwoven fabrics were constructed from the fresh wet fibers by hot pressing, and tested as wound dressings, showing excellent ability to accelerate healing, owing to the retainment of the intrinsic α-chitin structure.

Priming of the oxidative burst in rice and wheat cell cultures by ulvan, a polysaccharide from green macroalgae, and enhanced resistance against powdery mildew in wheat and barley plants

Abstract: The capacity of ulvan, a sulphated heteropolysaccharide, to prime the chitin- and chitosan-elicited oxidative burst in wheat and rice cells was tested. Gas-liquid chromatography showed that ulvan was composed of rhamnose, xylose, glucuronic acid, glucose and galactose. It contained very low amounts of proteins and ca. 19% sulphate groups. The polymer did not elicit the production of hydrogen peroxide in suspension-cultured wheat or rice cells. Furthermore, in both cell cultures, the simultaneous addition of ulvan and chitin hexamer or chitosan polymer did not significantly alter the intensity of the oxidative burst caused by the elicitors alone. However, pretreatment of wheat cells with ulvan increased the chitin-elicited oxidative burst about five- to sixfold, and that elicited by chitosan about twofold. In rice cells, the production of H2O2 elicited by chitin or chitosan was strongly primed by pretreatment with the same concentration of ulvan, increasing the burst triggered by the elicitors alone by 150 and 80 times, respectively. Pretreatment of whole plants with ulvan significantly reduced the symptom severity of Blumeria graminis infection, by 45% in wheat and by 80% in barley. Thus, the priming activity of ulvan on the oxidative burst correlates with a decrease of disease symptoms in infected plants. This is apparently the first report on priming activity of a natural algal polysaccharide.

Chitin Particles Are Multifaceted Immune Adjuvants

Abstract: Rationale: Chitin is a ubiquitous polysaccharide in fungi, insects, allergens, and parasites that is released at sites of infection. Its role in the generation of tissue inflammation, however, is not fully understood.Objectives: We hypothesized that chitin is an important adjuvant for adaptive immunity.Methods: Mice were injected with a solution of ovalbumin and chitin.Measurements and Main Results: We used in vivo and ex vivo/in vitro approaches to characterize the ability of chitin fragments to foster adaptive immune responses against ovalbumin and compared these responses to those induced by aluminum hydroxide (alum). In vivo, ovalbumin challenge caused an eosinophil-rich pulmonary inflammatory response, Th2 cytokine elaboration, IgE induction, and mucus metaplasia in mice that had been sensitized with ovalbumin plus chitin or ovalbumin plus alum. Toll-like receptor-2, MyD88, and IL-17A played critical roles in the chitin-induced responses, and MyD88 and IL-17A played critical roles in the alum-induced...