新型阿维菌素纳米控释剂的制备及性能研究
Fabrication of Novel Avermectin-porous Hollow Silica Nanoparticles (Av-PHSN) Carrier and Its Properties
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摘要: 提出利用无机-有机双模板法,即以纳米碳酸钙(平均粒径为70 nm左右)作为无机模板,表面活性剂吸附在其表面作为有机模板,以硅酸钠为硅源,通过溶胶-凝胶法,制备出空心多孔SiO2纳米颗粒,其粒径很小,平均约100 nm,壁厚大约15 nm,孔径约4.5 nm。首次采用空心多孔SiO2纳米颗粒作为控释载体对阿维菌素进行载药研究。结果表明:空心多孔SiO2纳米颗粒对阿维菌素有较强的吸附能力,包埋率高达62.5%;其对阿维菌素的吸附主要为物理吸附;初步观察发现,空心多孔SiO2纳米颗粒能够保护阿维菌素不被紫外光降解。阿维菌素纳米控释剂(Av-PHSN)在连续不断搅拌的溶出介质中的控制释放时间可长达33 h以上,这表明新型空心多孔SiO2纳米控释剂具有很好的缓释效果。因此,空心多孔SiO2纳米颗粒可望作为理想的新一代农药保护型控释载体。Abstract: Porous hollow silica nanoparticles (PHSN) with a diameter of ~100 nm and a pore size of ~4.5 nm were synthesized via a sol-gel route and using inorganic CaCO3 nanoparticles as templates. The as-synthesized PHSN were subsequently employed as novel pesticide carriers to study the controlled release behaviors of avermectin. The avermectin loaded PHSN (Av-PHSN) samples were characterized by BET, TG and IR. It showed that the encapsulation amount of avermectin in the PHSN carriers could reach 62.5% by a simple immersing loading method, and most adsorption of avermectin on the Av-PHSN carriers might be physical. Avermectin was released slowly into a bulk solution for about 2 000 minutes, thus exhibited a typical sustained release pattern without any burst effect. In addition, Av-PHSN carriers exhibited remarkable UV-shielding properties for avermectin. Therefore, it showed that the PHSN carriers have a promising future in applications of sustained pesticide release.
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