Engineering Research Centre of Plant Growth Regulators, Ministry of Education, College of Agronomy and Biotechnology, China Agricultural University, Beijing, PR China.
Pest Manag Sci. 2012 Mar;68(3):437-43. doi: 10.1002/ps.2288. Epub 2011 Oct 14.
The aim of this work is to prepare a controlled-release formulation of uniconazole using porous hollow silica nanoparticles (PHSNs) as carrier, and to investigate the biological effects on rice growth.
PHSNs with a shell thickness of ~15 nm and a particle size of 80-100 nm were synthesised through a sol-gel route using nanosized calcium carbonate particles as templates. Simple immersing (SI) and supercritical fluid drug loading (SFDL) technologies were employed to load uniconazole into PHSNs with loading efficiencies of ~22 and ~26% respectively. The prepared uniconazole-loaded PHSNs (UCZ-PHSNs) by SI and SFDL both demonstrated sustained release properties, and the latter showed better controlled release ability with a slower release rate. Compared with free uniconazole, UCZ-PHSNs exhibited a weaker growth retardation effect in the early stage but more significant retardation ability in later stages for agar-cultured rice seedlings. For the rice that grew in clay, UCZ-PHSNs demonstrated a weaker plant height retardation effect than free uniconazole at the early jointing stage by foliar spraying, but exhibited a stronger retardation capacity than free uniconazole by being applied into soil before seedling transplantation.
The results indicated that the prepared UCZ-PHSNs possessed good controlled-release properties and had improved retardation effects on rice growth. It is recommended that UCZ-PHSNs be applied into soil before seedling transplantation rather than administered by foliar spraying at the early jointing stage.
本工作旨在制备一种使用多孔中空硅纳米粒子（PHSNs）作为载体的咪鲜胺控释制剂，并研究其对水稻生长的生物效应。
通过纳米碳酸钙颗粒作为模板的溶胶-凝胶路线合成了壳厚约 15nm、粒径为 80-100nm 的 PHSNs。采用简单浸渍（SI）和超临界流体药物加载（SFDL）技术将咪鲜胺分别负载到 PHSNs 中，载药效率约为 22%和 26%。通过 SI 和 SFDL 制备的载咪鲜胺的 PHSNs（UCZ-PHSNs）均表现出持续释放特性，后者具有更好的控制释放能力，释放速度较慢。与游离咪鲜胺相比，UCZ-PHSNs 在琼脂培养的水稻幼苗早期表现出较弱的生长抑制作用，但在后期表现出更强的抑制能力。对于在粘土中生长的水稻，通过叶面喷施，UCZ-PHSNs 在早期分孽期比游离咪鲜胺表现出较弱的株高抑制作用，但在移栽前施入土壤中比游离咪鲜胺表现出更强的抑制能力。
结果表明，所制备的 UCZ-PHSNs 具有良好的控释性能，对水稻生长的抑制作用得到改善。建议在移栽前将 UCZ-PHSNs 施入土壤，而不是在早期分孽期进行叶面喷施。
