Chitosan can stop or postpone the death of the suckling mice challenged with foot-and-mouth disease virus

In the study, a method called "hardening in liquid phase" for preparing chitosan granules with glutaraldehyde as crosslinker and Tween 80 as surfactant and paraffin liquid as dispersant was established. The chitosan granules were light yellow and insoluble in water or oil, but they swelled in acid solution and narrowed in neutral or alkaline solution. Furthermore, some of characteristics of the chitosan granules were revealed. (a) Stability: Their shapes were stable at pH 7.0 and pH 8.0 and -30°C~120°C. The shelf life is at least one year in vitro at room temperature. (b) Safety: Some experiments of their lethal effect to suckling mice and pathogenicity to mature mice proved the chitosan granules were harmless. (c) Antiviral activity: Some suckling mice injected with chitosan granules were still alive or delayed death compared with control group when they challenged with foot-and-mouth disease virus (FMDV). Such anti-FMDV capacity could maintain 1 week and was the strongest on the third day.