Preparation and properties of chitosan nanocapsules loaded with tebuconazole

Tebuconazole-loaded nanocapsules were synthesized by self-assembly method,with cores of tebuconazole and walls of chitosan and polymethylmethacrylate.The mean particle diameter(D50) and particle dispersion index(PDI) of the nanocapsules were 220 nm and 0.23,characterized by dynamic light scattering(DLS) and transmission electron microscope(TEM).The drug loading efficiency,encapsulation rate and release characteristics of the nanocapsules in vitro at 192 h were 21.8%,85.7% and 65.97% respectively,measured by high performance liquid chromatography.The fungicidal activity of tebuconazole-loaded nanocapsules against three kinds of wood and bamboo fungus was tested by poisoned medium method.Compared with the same mass concentration(48.2 mg/L) of tebuconazole ethyl acetate solution,tebuconazole-loaded nanocapsules exhibited lower fungicidal activity within 20 days,but maintained higher fungicidal activity as time prolonged.The inhibition rate of the tebuconazole-loaded nanocapsules against Trichoderma viride,Penicillam citrinum and Aspergillus niger were 70.6%,66.4% and 89.1% respectively on the 40th day.The results of present study would provide useful information for the development of wood and bamboo nanocapsules preservative.